WorldWideScience

Sample records for backfill soils

  1. 分层填土作用在挡土墙上的主动土压力%Active Soil Pressure on Retaining Wall With Layered Backfills

    Institute of Scientific and Technical Information of China (English)

    杨雪强

    2001-01-01

    基于土的塑性极限分析理论,考虑墙后分层填土的滑动变形协调条件,探讨了分层填土作用在挡土墙上主动土压力的计算方法,得出了一些有益的结论.%Based on soil plasticity and limit analysis theory,together with sliding harmonious condition of layered backfills,calculating method of active soil pressure on retaining wall with layered backfills is proposed,and corresponding conclusions are also made in this paper.

  2. Experimental Evaluation of Backfill in Scour Holes around Offshore Monopiles

    DEFF Research Database (Denmark)

    Sørensen, Søren Peder Hyldal; Ibsen, Lars Bo; Frigaard, Peter

    2010-01-01

    . Currently there is no knowledge concerning the relative density, and hereby also the strength and deformation properties of the backfilled soil material. The strength of the backfilled soil and the time scale of respective erosion and backfilling is of high importance when designing the steel structure...

  3. Geotechnical considerations in mine backfilling in Australia

    Energy Technology Data Exchange (ETDEWEB)

    N. Sivakugan; R.M. Rankine; K.J. Rankine; K.S. Rankine [James Cook University, Townsville, Qld. (Australia). School of Engineering

    2006-07-01

    Mine backfilling can play a significant role in the overall operation of a mine operation. In the Australian mining industry, where safety is a prime consideration, hydraulic systems are the most common backfills deployed. Many accidents reported at hydraulic fill mines worldwide have mainly been attributed to a lack of understanding of their behaviour and barricade bricks. There are two basic types of backfilling strategies. The first, uncemented backfilling, does not make use of binding agents such as cement, and their characteristics can be studied using soil mechanics theories. A typical example of uncemented backfilling is the use of hydraulic fills that are placed in the form of slurry into the underground voids. The second category, cemented backfilling, makes use of a small percentage of binder such as Portland cement or a blend of Portland cement with another pozzolan such as fly ash, gypsum or blast furnace slag. This paper describes the findings from an extensive laboratory test programme carried out in Australia on more than 20 different hydraulic fills and several barricade bricks. A limited description of paste backfills is also provided, and the usefulness of numerical modelling as an investigative tool is highlighted. 21 refs., 10 figs., 1 tab.

  4. Discussion on counter-digging and backfill methods of low filling soil roadbed%谈低填方土质路基工程反挖回填施工方法

    Institute of Scientific and Technical Information of China (English)

    赵伟

    2012-01-01

    Combining with roadbed counter-digging and backfill engineering at contraction section of national highway line No. 208 reconstruction project, this thesis introduces counter-digging and backfill methods of low filling soil roadbed, and summarizes some technological points, which has laid a foundation for the application of counter-digging method in roadbed engineering.%结合国道208线改建工程某合同段路基反挖回填工程施工实例,介绍了低填方土质路基反挖回填施工方法,并总结了一些技术要点,为推广该施工方法在路基工程中的应用奠定了基础。

  5. A New Mode of Coal Mining Under Buildings with Paste-Like Backfill Technology

    Institute of Scientific and Technical Information of China (English)

    崔建强; 孙恒虎; 黄玉诚

    2002-01-01

    The formation of the paste-like backfill technology was introduced briefly in this paper. From the actual cases of coal mines, a new mode of coal mining un der buildings with the technology was proposed. And its specificity was analyzed , and a further introduction to the full-sand-soil solidifying material was given. The main parts of the backfill system, such as the backfill preparation system, the pipeline transportation system, the backfill systems in fully-mechanized mining faces and the backfill process, were presented emphatically.

  6. RESEARCH ON ACTIVE EARTH PRESSURE BEHIND RIGID RETAINING WALL FROM CLAYEY BACKFILL CONSIDERING SOIL ARCHING EFFECTS%考虑土拱效应的黏性填土挡土墙主动土压力研究

    Institute of Scientific and Technical Information of China (English)

    涂兵雄; 贾金青

    2012-01-01

    Analytical expressions for the active earth pressure ratio and active earth pressure are derived, against on a rigid retaining wall from clayey backfill undergoing horizontal translation) considering the soil arching effects and the influence of soil-wall friction angle, wall adhesion and cohesion of backfill. The results show that the active earth pressure ratio and active earth pressure are related to soil-wall friction angle, depth of the point and the internal friction angle, cohesion, unit weight of the backfill. The theoretical comparisons between the analytical expressions proposed for active earth pressure ratio and active earth pressure and the existing classical theory, the previous research results show great agreement with each other, so as to verity the correctness of the results in this paper.%以墙后填土为黏性土的刚性挡土墙为研究对象,考虑挡土墙后的土拱效应,以及墙土摩擦角、墙土黏结力、墙后填土黏聚力的影响,推导挡土墙在平动模式下的主动土压力系数和主动土压力解析解.结果表明,考虑土拱效应的主动土压力系数和主动土压力均与墙土摩擦角、计算点深度以及墙后填土的内摩擦角、黏聚力及重度有关.通过将求解的主动土压力系数和主动土压力与现有经典理论解及前人理论研究成果对比,发现结果完全吻合,验证该研究结果的正确性.

  7. On the risk of liquefaction of buffer and backfill

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, R. [Geodevelopment AB, Lund (Sweden)

    2000-10-01

    The necessary prerequisites for liquefaction of buffers and backfills in a KBS-3 repository exist but the stress conditions and intended densities practically eliminate the risk of liquefaction for single earthquakes with magnitudes up to M=8 and normal duration. For buffers rich in expandable minerals it would be possible to reduce the density at water saturation to 1,700 - 1,800 kg/m{sup 3} or even less without any significant risk of liquefaction, while the density at saturation of backfills with 10 - 15% expandable clay should not be reduced to less than about 1,900 kg/m{sup 3}. Since the proposed densities of both buffers and backfills will significantly exceed these minimum values it is concluded that there is no risk of liquefaction of the engineered soil barriers in a KBS-3 repository even for very significant earthquakes.

  8. Backfilling and closure of the deep repository. Assessment of backfill concepts

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarsson, David; Boergesson, Lennart [Clay Technology AB, Lund (Sweden); Keto, Paula [Saanio Riekkola Oy (Finland); Tolppanen, Pasi [Jaakko Poeyry Infra (Finland); Hansen, Johanna [Posiva Oy, Helsinki (Finland)

    2004-06-01

    This report presents the results from work made in Phase 1 of the joint SKB-Posiva project 'Backfilling and Closure of the Deep Repository' aiming at selecting and developing materials and techniques for backfilling and closure of a KBS-3 type repository for spent nuclear fuel. The aim of phase 1, performed as a desk study, was to describe the potential of the suggested backfill concepts in terms of meeting SKB and Posiva requirements, select the most promising ones for further investigation, and to describe methods that can be used for determining the performance of the concepts. The backfilling concepts described in this report differ from each other with respect to backfill materials and installation techniques. The concepts studied are the following: Concept A: Compaction of a mixture of bentonite and crushed rock in the tunnel. Concept B: Compaction of natural clay with swelling ability in the tunnel. Concept C: Compaction of non-swelling soil type in the tunnel combined with application of pre-compacted bentonite blocks at the roof. Concept D: Placement of pre-compacted blocks; a number of materials are considered. Concept E: Combination of sections consisting of a) crushed rock compacted in the tunnel and b) pre-compacted bentonite blocks. The bentonite sections are installed regularly above every disposal hole. Concept F: Combination of sections consisting of a) crushed rock compacted in the tunnel and b) pre-compacted bentonite blocks. The distance between the bentonite sections is adapted to the local geology and hydrology.The assessment of the concepts is based on performance requirements set for the backfill in the deposition tunnels for providing a stable and safe environment for the bentonite buffer and canister for the repository service time. In order to do this, the backfill should follow certain guidelines, 'design criteria' concerning compressibility, hydraulic conductivity, swelling ability, long-term stability, effects on

  9. The Buffer and Backfill Handbook. Part 2: Materials and techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Geodevelopment AB, Lund (Sweden)

    2001-12-01

    Improved technology and prospection yielding more pure and homogeneous raw materials for preparing buffers and backfills will ultimately outdate the clays and ballast materials described in the present part of the Handbook. It describes experimentally investigated materials of potential use in repositories but other, more suitable materials will replace them in the future. The Handbook will hence have to be reviewed regularly, making room for superior materials in future, upgraded Handbook versions. Buffer is the term for dense clay used for embedment of canisters with highly radioactive waste, while backfill is soil used for filling tunnels and shafts in repositories. Examples of soil materials of potential use as buffers and backfills in repositories of KBS-3 type are described in this part of the Handbook. They are: smectitic clay materials intended for preparation of buffers (canister-embedding clay) and used as clay component in artificially prepared tunnel and shaft backfills consisting of mixtures of clay and ballast. Ballast materials intended for backfilling of tunnels and shafts and used as components of artificially prepared backfills. Smectitic natural clay soils intended for use as buffers and backfills. Very fine-grained smectite clay used as grout for sealing rock fractures. In this part of the Handbook for Buffers and Backfills, description of various candidate materials will be made with respect to their mineral composition and physical properties, with respect to the groundwater chemistry that can be expected in a deep repository in Swedish bedrock. Chapter 3 deals with smectitic clay materials intended for embedment of heat-producing canisters with highly radioactive waste. Focus is on the nature of the buffer constituents, i. e. the smectite content, the non-expanding clay minerals colloidal and the accessory non-clay minerals as well as amorphous matter and organic substances. The dominant part of the chapter describes the occurrence and origin

  10. Horizontal roof gap of backfill hydraulic support

    Institute of Scientific and Technical Information of China (English)

    张强; 张吉雄; 邰阳; 方坤; 殷伟

    2015-01-01

    For the backfill hydraulic support as the key equipment for achieving integration of backfilling and coal mining simultaneously in the practical process, its characteristics will directly influence the backfill body’s compression ratio. Horizontal roof gap, as a key parameter of backfilling characteristics, may impact the backfilling effect from the aspects of control of roof subsidence in advance, support stress, backfilling process and the support design. Firstly, the reason why horizontal roof gap exists was analyzed and its definition, causes and connotation were introduced, then adopting the Pro/E 3D simulation software, three typical 3D entity models of backfill hydraulic supports were built, based on the influence of horizontal roof gap on backfilling effect, and influence rules of four factors, i.e. support height, suspension height, suspension angle and tamping angle, were emphatically analyzed on horizontal roof gap. The results indicate that, the four factors all have significant impacts on horizontal roof gap, but show differences in influence trend and degree, showing negative linear correlation, positive linear correlation, positive semi-parabolic correlation and negative semi-parabolic correlation, respectively. Four legs type is the most adaptive to the four factors, while six legs (II) type has the poorest adaptability, and the horizontal roof gap is small under large support height, small suspension height, small suspension angle and large tamping angle situation. By means of optimizing structure components and their positional relation and suspension height of backfill scrape conveyor in the process of support design and through controlling working face deployment, roof subsidence in advance, mining height and backfilling during engineering application, the horizontal roof gap is optimized. The research results can be served as theoretical basis for support design and guidance for backfill support to have better performance in backfilling.

  11. Flowable Backfill Materials from Bottom Ash for Underground Pipeline

    Directory of Open Access Journals (Sweden)

    Kyung-Joong Lee

    2014-04-01

    Full Text Available The purpose of this study was to investigate the relationship between strength and strain in manufacturing controlled low strength materials to recycle incineration bottom ash. Laboratory tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. The optimum mixing ratios were 25%–45% of in-situ soil, 30% of bottom ash, 10%–20% of fly ash, 0%–3% of crumb rubber, 3% of cement, and 22% of water. Each mixture satisfied the standard specifications: a minimum 20 cm of flowability and 127 kPa of unconfined compressive strength. The average secant modulus (E50 was (0.07–0.08 qu. The ranges of the internal friction angle and cohesion for mixtures were 36.5°–46.6° and 49.1–180 kPa, respectively. The pH of all of the mixtures was over 12, which is strongly alkaline. Small-scale chamber tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. Vertical deflection of 0.88–2.41 mm and horizontal deflection of 0.83–3.72 mm were measured during backfilling. The vertical and horizontal deflections of controlled low strength materials were smaller than that of sand backfill.

  12. Colonization of compacted backfill materials by microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Lucht, L.M.; Stroes-Gascoyne, S.; Miller, S.H.; Hamon, C.J.; Dixon, D.A

    1997-11-01

    Experiments were carried out to investigate the occurrence of pore clogging in backfill by bacterial activity. Four differently prepared and treated backfill materials were used to determine the effects of the quality and preparation method of the backfill materials on the occurrence of pore clogging. The backfills were compacted in permeameters which were infused with either groundwater or sterile distilled water. A constant pressure was applied to increase the rate of saturation. Results showed different inflow rates for the four materials despite the use of the same packing method for each specimen, the same dry density for each backfill and indications of similar initial pore volumes. These differences were likely caused by the fact that the two slowest-flowing permeameters contained a mixture of Na-bentonite and illitic shale simulating a glacial lake clay. Hydraulic conductivities measured ranged from 5 x 10{sup -11} m/s to 5 x 10{sup -12} m/s for the backfills containing glacial lake clay and 4 x 10{sup -12} m/s to 9 s 10{sup -13} m/s for the backfills containing a mixture of Na-bentonite and illitic shale. Weekly samples of outflow from the permeameters were analyzed microbially. Aerobic heterotrophs were low initially but stabilized around 10{sup 6} to 10{sup 7} colony forming units (CFU)/mL after about one week. Anaerobic heterotrophs stabilized at around 10{sup 2} to 10{sup 3} CFU/mL. Sulphate-reducing bacteria (SRB) were measured by the most probable number (MPN) method. Results showed low initial numbers but they stabilized around 10{sup 4} MPN/mL after one to two months. No significant numbers of aerobic or anaerobic sulphur oxidizing bacteria were found. Enumeration of methanogens indicated that they were generally present in the permeameters that contained non-autoclaved backfill. Results are partially inconclusive because of the lack of confirmation of methane gas present in the headspace of part of the MPN culture tubes. Microbial pore clogging

  13. A Historical Review of WIPP Backfill Development

    Energy Technology Data Exchange (ETDEWEB)

    Brush, L.H.; Krumhansl, J.L.; Molecke, M.A.; Papenguth, H.W.

    1999-07-15

    Backfills have been part of Sandia National Laboratories' [Sandia's] Waste Isolation Pilot Plant [WIPP] designs for over twenty years. Historically, backfill research at Sandia has depended heavily on the changing mission of the WIPP facility. Early testing considered heat producing, high level, wastes. Bentonite/sand/salt mixtures were evaluated and studies focused on developing materials that would retard brine ingress, sorb radionuclides, and withstand elevated temperatures. The present-day backfill consists of pure MgO [magnesium oxide] in a pelletized form and is directed at treating the relatively low contamination level, non-heat producing, wastes actually being disposed of in the WIPP. It's introduction was motivated by the need to scavenging CO{sub 2} [carbon dioxide] from decaying organic components in the waste. However, other benefits, such as a substantial desiccating capacity, are also being evaluated. The MgO backfill also fulfills a statutory requirement for assurance measures beyond those needed to demonstrate compliance with the US Environmental Protection Agency [EPA] regulatory release limits. However, even without a backfill, the WIPP repository design still operates within EPA regulatory release limits.

  14. Performance of cemented coal gangue backfill

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qin-li; WANG Xin-min

    2007-01-01

    Possibility of cemented gangue backfill was studied with gangue of Suncun Coal Mine, Xinwen Coal Group, Shandong,and fly ash of nearby thermal power plant, in order to treat enormous coal gangue on a large scale and to recovery safety coal pillars.The results indicate that coal gangue is not an ideal aggregate for pipeline gravity flow backfill, but such disadvantages of gangue as bad fluidity and serious pipe wear can be overcome by addition of fly ash. It is approved that quality indexes such as strength and dewatering ratio and piping feature of slurry can satisfy requirement of cemented backfill if mass ratio of cement to fly ash to gangue higher middle and long term comprehensive strength.

  15. Implementation of Paste Backfill Mining Technology in Chinese Coal Mines

    OpenAIRE

    Qingliang Chang; Jianhang Chen; Huaqiang Zhou; Jianbiao Bai

    2014-01-01

    Implementation of clean mining technology at coal mines is crucial to protect the environment and maintain balance among energy resources, consumption, and ecology. After reviewing present coal clean mining technology, we introduce the technology principles and technological process of paste backfill mining in coal mines and discuss the components and features of backfill materials, the constitution of the backfill system, and the backfill process. Specific implementation of this technology a...

  16. Numerical calculation of backfilling of scour holes

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Baykal, Cüneyt; Fuhrman, David R.;

    2014-01-01

    A fully-coupled hydrodynamic and morphologic CFD model is presented for simulating backfilling processes around structures. The hydrodynamic model is based on Reynolds-averaged Navier-Stokes equations, coupled with two-equation k-ω turbulence closure. The sediment transport model consists of sepa...

  17. Assessment of backfill design for KBS-3V repository

    Energy Technology Data Exchange (ETDEWEB)

    Keto, Paula (B+tech, Eurajoki (Finland)); Dixon, David (AECL, Harwell (United Kingdom)); Jonsson, Esther; Gunnarsson, David (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Boergesson, Lennart (Clay Technology AB, Lund (Sweden)); Hansen, Johanna (Posiva (Finland))

    2009-12-15

    Posiva and SKB initiated a joint programme BACLO (Backfilling and Closure of the Deep repository) in 2003 with the aim to develop methods and materials for backfilling of deposition tunnels. This report summarises the work done in the third and final phase of the BACLO programme. The main objective of this phase was to study how the various processes active during backfill installation and saturation as well as technical constraints affect its design basis. The work focused on the performance and technical feasibility of a block backfill concept, which calls for filling the majority of the tunnel volume with pre-compacted backfill blocks and the remaining volume with bentonite pellets. Several backfill composition alternatives were chosen for study and they consisted of clay materials with differing amounts of swelling minerals. A large body of information was gained on the effect of different processes on the performance of these backfill options, e.g. water inflow, piping, erosion, self-healing, homogenisation and interaction between backfill and buffer in various laboratory and small-scale field tests. More practical tests included e.g. studies how the blocks and pellets could be installed to the deposition tunnel. Based on the new information on the effect of the processes investigated and the estimated achievable block filling degree and backfill density, recommendations were made concerning material selection, backfill layout and technical issues. In addition, issues requiring further attention to verify the long-term performance of the proposed backfill concept are identified and listed

  18. Implementation of Paste Backfill Mining Technology in Chinese Coal Mines

    Directory of Open Access Journals (Sweden)

    Qingliang Chang

    2014-01-01

    Full Text Available Implementation of clean mining technology at coal mines is crucial to protect the environment and maintain balance among energy resources, consumption, and ecology. After reviewing present coal clean mining technology, we introduce the technology principles and technological process of paste backfill mining in coal mines and discuss the components and features of backfill materials, the constitution of the backfill system, and the backfill process. Specific implementation of this technology and its application are analyzed for paste backfill mining in Daizhuang Coal Mine; a practical implementation shows that paste backfill mining can improve the safety and excavation rate of coal mining, which can effectively resolve surface subsidence problems caused by underground mining activities, by utilizing solid waste such as coal gangues as a resource. Therefore, paste backfill mining is an effective clean coal mining technology, which has widespread application.

  19. Implementation of paste backfill mining technology in Chinese coal mines.

    Science.gov (United States)

    Chang, Qingliang; Chen, Jianhang; Zhou, Huaqiang; Bai, Jianbiao

    2014-01-01

    Implementation of clean mining technology at coal mines is crucial to protect the environment and maintain balance among energy resources, consumption, and ecology. After reviewing present coal clean mining technology, we introduce the technology principles and technological process of paste backfill mining in coal mines and discuss the components and features of backfill materials, the constitution of the backfill system, and the backfill process. Specific implementation of this technology and its application are analyzed for paste backfill mining in Daizhuang Coal Mine; a practical implementation shows that paste backfill mining can improve the safety and excavation rate of coal mining, which can effectively resolve surface subsidence problems caused by underground mining activities, by utilizing solid waste such as coal gangues as a resource. Therefore, paste backfill mining is an effective clean coal mining technology, which has widespread application.

  20. Tunnel backfill erosion by dilute water

    Energy Technology Data Exchange (ETDEWEB)

    Olin, M. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2014-03-15

    The goal was to estimate smectite release from tunnel backfill due to dilute groundwater pulse during post glacial conditions. The plan was to apply VTT's two different implementations (BESW{sub D} and BESW{sub S}) of well-known model of Neretnieks et al. (2009). It appeared difficult to produce repeatable results using this model in COMSOL 4.2 environment, therefore a semi-analytical approximate approach was applied, which enabled to take into account both different geometry and smectite content in tunnel backfill as compared to buffer case. The results are quite similar to buffer results due to the decreasing effect of smaller smectite content and the increasing effect of larger radius. (orig.)

  1. Some characteristics of potential backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, D.R.

    1983-05-01

    A backfill material is one of the multiple barriers that may be involved in the disposal of nuclear waste. Such backfill should be a desiccant with the hydrous product having acceptable stability; it should sorb any released radioisotopes, and it should reseal any breached site. The backfill must also have acceptable thermal conductivity. This report presents data on the rate of hydration and the nature of the product of reaction of some candidate backfill materials with water and with brine. Thermal conductivity data is reported for both the reactants and the products. Granular MgO at 150/sup 0/C completely hydrates in less than 10 hours. At 60/sup 0/C and 20/sup 0/C, such extensive hydration requires about 100 and 1000 hours, respectively. The product of the reaction is stable to more than 300/sup 0/C. A doped discalcium silicate was less reactive and the product contains less water of crystallization than the MgO. The reaction product of dicalcium silicate is cementous, but it has low thermal stability. Bentonite readily reacts with water and expands. The reaction product has the properties of vermiculite, which indicates that magnesium ions have diffused into the bentonite structure and are not simply adsorbed on the surface. If bentonite is emplaced in a saline environment, the properties of vermiculite, the reaction product, should also be considered. The thermal conductivity of MgO, discalcium silicate, and bentonite is primarily dependent on the porosity of the sample. A slight increase in thermal conductivity was found with increased temperature, in contrast to most rocks. If the conductive data for the different materials is equated to the same porosity, MgO has the superior thermal conductivity compared to bentonite or discalcium silicate.

  2. Hydraulic calculation of gravity transportation pipeline system for backfill slurry

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qin-li; HU Guan-yu; WANG Xin-min

    2008-01-01

    Taking cemented coal gangue pipeline transportation system in Suncun Coal Mine, Xinwen Mining Group, Shandong Province, China, as an example, the hydraulic calculation approaches and process about gravity pipeline transportation of backfill slurry were investigated. The results show that the backfill capability of the backfill system should be higher than 74.4m3/h according to the mining production and backfill times in the mine; the minimum velocity (critical velocity) and practical working velocity of the backfill slurry are 1.44 and 3.82m/s, respectively. Various formulae give the maximum ratio of total length to vertical height of pipeline (L/H ratio) of the backfill system of 5.4, and then the reliability and capability of the system can be evaluated.

  3. A simplified DEM numerical simulation of vibroflotation without backfill

    Science.gov (United States)

    Jiang, M. J.; Liu, W. W.; He, J.; Sun, Y.

    2015-09-01

    Vibroflotation is one of the deep vibratory compaction techniques for ground reinforcement. This method densities the soil and improves its mechanical properties, thus helps to protect people's lives and property from geological disasters. The macro reinforcement mechanisms of vibroflotation method have been investigated by numerical simulations, laboratory and in-situ experiments. However, little attention has been paid on its micro - mechanism, which is essential to fully understand the principle of the ground reinforcement. Discrete element method (DEM), based on discrete mechanics, is more powerful to solve large deformation and failure problems. This paper investigated the macro-micro mechanism of vibroflotation without backfill under two conditions, i.e., whether or not the ground water was considered, by incorporating inter-particle rolling resistance model in the DEM simulations. Conclusions obtained are as follows: The DEM simulations incorporating rolling resistance well replicate the mechanical response of the soil assemblages and are in line with practical observations. The void ratio of the granular soil fluctuates up and down in the process of vibroflotation, and finally reduces to a lower value. It is more efficient to densify the ground without water compared to the ground with water.

  4. Backfilling of trenches exposed to waves

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Fredsøe, Jørgen

    1997-01-01

    This paper treats the numerical prediction of initial and long-term morphology of small pipeline trenches. For this purpose a refined flow and sediment transport description is applied such that the entire mathematical problem is formulated and solved on a curvilinear grid using a k - ε turbulence...... of a particle in waves and L the trench length, is investigated in detail, and an optimal KC-number for the backfilling rate is found. Coherent structures in the non-uniform unsteady trench-flow are shown to dominate the deposition rate when present. The importance of a detailed description of the flow...

  5. 30 CFR 816.105 - Backfilling and grading: Thick overburden.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Backfilling and grading: Thick overburden. 816...-SURFACE MINING ACTIVITIES § 816.105 Backfilling and grading: Thick overburden. (a) Definition. Thick... surrounding terrain. (b) Performance standards. Where thick overburden occurs within the permit area,...

  6. 露天坑回填土石混合体的渗流特性及颗粒元数值分析%PERMEABILITY CHARACTERISTICS OF ROCK AND SOIL AGGREGATE OF BACKFILLING OPEN-PIT AND PARTICLE ELEMENT NUMERICAL ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    高谦; 刘增辉; 李欣; 李俊华

    2009-01-01

    Combining with the backfilling(RSA) engineering in stope III of Sijiaying open-pit to underground iron mining of Hebei Iron and Steel Group Mining Co.,Ltd.,the permeability of rock and soil aggregate(RSA) is studied systematically by laboratory test,in-situ experiment and numerical simulation. The results show that there is an approximation linear relationship between the permeability coefficient of RSA and its non-uniform degree,and the permeability coefficient of RSA is directly proportional to the void ratio. The permeability of RSA can be reduced effectively by controlling the gradation of particle size of waste rock backfilled and reducing the average particle size and non-uniformity reasonably. The influence order to the seepage discharge of RSA is determined by particle element numerical orthogonal tests. The relationship formulas of the effects of four factors(thickness of back-packing,head pressure,porosity,particle diameter) on the seepage are obtained by quadratic stepwise regression analysis,and it can provide a calculation tool for impermeability of RSA.%针对土石混合体的渗透性,结合唐钢司家营铁矿III采场露天转井下的回填土石混合体工程,采用室内试验、现场试验和数值模拟的方法对其进行系统地研究,得出土石混合体的渗透系数与其非均匀度近似存在线性关系,渗透系数与混合土的孔隙比成正比;合理控制回填废石的粒径级配,降低平均粒径与非均匀度,可有效降低回填土石混合体的渗透性.通过颗粒元数值正交试验确定对土石混合体的渗流量影响顺序,并二次逐步回归出回填层厚度,水头压力,孔隙率,平均粒径对渗流量的关系式,为土石混合体防渗抗渗提供计算工具.

  7. Strata movement controlling effect of waste and fly ash backfillings in fully mechanized coal mining with backfilling face

    Institute of Scientific and Technical Information of China (English)

    Zhang Jixiong; Zhang Qiang; Huang Yanli; Liu Jinwei; Zhou Nan; Zan Dongfeng

    2011-01-01

    A fully mechanized coal mining with backfilling (FMCMB) provides advantages of safety and efficiency for coal mining under buildings,railways,and water bodies.According to the field geological conditions,we analyzed the controlling effect of strata movement by the waste and fly ash backfilling in FMCMB face.Based on the key strata theory,we established the equivalent mining thickness model,and analyzed the action of the bulk factor of backfilling body to the equivalent mining thickness.In addition,we numerically simulated the controlling function of the strata movement by backfilling bodies with different strength.And the numerical simulation result show that the deformation of stratum and the subsidence of surface can be controlled by FMCMB.The result provides references to the effective execution of fully mechanized coal mining with solid waste backfilling in goal.

  8. Application of paste backfill in underground coal fires

    Energy Technology Data Exchange (ETDEWEB)

    Drebenstedt, C.; Masniyom, M. [Technische Univ., Freiberg (Germany)

    2009-07-01

    Coal fires are common in most coalfields around the world, and most particularly in China. The main countries affected by coal fires include China, India, the United States, Australia, Indonesia and South Africa. The fires cause sinkholes; large-scale subsidence; air pollution in the form of greenhouse gases; global warming; loss of mining productivity; contamination of drinking water; damage of flora and fauna; and a high safety risk. Therefore, protecting the economically valuable coal resources and the environment is of significant national and international importance. This paper discussed the use of paste backfill in the Wuda Inner Mongolia coalfield to cool down the burning coal and cut off the air supply to prevent coal fires. The study investigated backfill materials and techniques suited for underground coal fires. The paper presented the results of laboratory tests that were conducted on physical, chemical and mechanical properties of different backfill materials and mixtures, with particular attention to materials generated as by-products and other cheaply available materials such as fly ash from power plants. The characteristics of backfill materials, grain size analysis, and chemical composition of backfill were also identified. It was concluded that backfilling voids enhance the stability of the mine, thereby improving safety for the workforce. 4 refs., 2 tabs., 4 figs.

  9. Closure of the Brewer Gold Mine by pit backfilling

    Energy Technology Data Exchange (ETDEWEB)

    Lewis-Russ, A.; Lupo, J.F. [Titan Environmental Corp., Englewood, CO (United States); Bronson, J.M. [Titan Environmental Corp., Tempe, AZ (United States)] [and others

    1996-12-31

    Brewer Gold Mine, located in north-central South Carolina, is implementing an innovative reclamation plan that includes backfilling the main Brewer open pit with mine waste. The primary goals of the closure are to reduce acid rock drainage and minimize or eliminate long-term operation and maintenance requirements by restoring the site property to approximate pre-mining topography. The plan calls for consolidation of approximately 200 acres of waste into approximately 20 hectares (50 acres). Much of the material to be backfilled into the pit, including spent heap leach material and waste rock, has acid-generating potential. Therefore, the backfill design integrated geochemical properties of the backfill materials with expected post-closure conditions. A prime consideration was the final position of the water table. Since mining at the site started in the early 1800`s, no records exist of the original groundwater levels. Therefore, the design incorporates a large anoxic limestone drain to control the final groundwater level. Additional amendments are to be placed in targeted areas of the backfill to maximize their utilization. A low-permeability cap system that includes a GEOSYNTHETIC clay liner has been designed to limit infiltration into the backfill.

  10. Status of Research on Magnesium Oxide Backfill

    Energy Technology Data Exchange (ETDEWEB)

    PAPENGUTH,HANS W.; KRUMHANSL,JAMES L.; BYNUM,R. VANN; WANG,YIFENG; KELLY,JOHN W.; ANDERSON,HOWARD; NOWAK,E. JAMES

    2000-07-31

    For the WIPP, chemical and physical characteristics of MgO suggest it to be the most beneficial backfill choice, particularly because it has the ability to buffer the aqueous chemical conditions to control actinide volubility. In the current experimental program, the authors are developing a technical basis for taking credit for the complete set of attributes of MgO in geochemical, hydrogeological, and geomechanical technical areas, resulting in an improved conceptual model for the WIPP such as the following. Water uptake by MgO will delay the development of mobile actinides and gas generation by microbes and corrosion. Reduced gas generation will reduce or even eliminate spallings releases. As MgO hydrates, it swells, reducing porosity and permeability, which will inhibit gas flow in the repository, in turn reducing spallings releases. Hydration will also result in a self-sealing mechanism by which water uptake and swelling of MgO adjacent to a groundwater seep cuts off further seepage. Reaction with some groundwaters will produce cementitious materials, which will help to cement waste particles or produce a cohesive solid mass. Larger particles are less likely to be entrained in a spallings release. If sufficient water eventually accumulates in a repository to support microbial gas generation, magnesium carbonate cements will form; also producing good cohesion and strength.

  11. Backfilling of deposition tunnels: Use of bentonite pellets

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David (Atomic Energy of Canada Limited (Canada)); Sanden, Torbjoern (Clay Technology AB (Sweden)); Jonsson, Esther (Swedish Nuclear Fuel and Waste Mangaement Co. (Sweden)); Hansen, Johanna (Posiva Oy (Finland))

    2011-02-15

    The state of knowledge related to use of bentonite pellets as part of backfill or other gap filling components in repository applications is reviewed. How the pellets interact with adjacent sealing materials and the surrounding rock mass is a critical aspect in determining backfill behaviour. The key features and processes that determine how the pellet component of the KBS-3V deposition tunnel backfill will behave are discussed and recommendations related to what additional information needs to be developed are provided. Experiences related to pellet material composition, size, shape, placement options and more importantly, the density to which they can be placed all indicate that there are significant limitations to the achievable as-placed density of bentonite pellet fill. Low as-placed density of the pellet fill component of the backfill is potentially problematic as the outermost regions of tunnel backfill will be the first region of the backfill to be contacted by water entering the tunnels. It is also through this region that initial water movement along the length of the deposition tunnels will occur. This will greatly influence the operations in a tunnel, especially with respect to situations where water is exiting the downstream face of still open deposition tunnels. Pellet-filled regions are also sensitive to groundwater salinity, susceptible to development of piping features and subsequent mechanical erosion by through flowing water, particularly in the period preceding deposition tunnel closure. A review of the experiences of various organisations considering use of bentonite-pellet materials as part of buffer or backfill barriers is provided in this document. From this information, potential options and limitations to use of pellets or pellet-granule mixtures in backfill are identified. Of particular importance is identification of the apparent upper-limits of dry density to which such materials can to be placed in the field. These bounds will

  12. Experimental and Numerical Study of Wave-Induced Backfilling Beneath Submarine Pipelines

    DEFF Research Database (Denmark)

    Bayraktar, Deniz; Ahmad, Joseph; Eltard-Larsen, Bjarke

    Through complementary experimental and numerical efforts, the present paper aims to make a significant contribution to the overall understanding of backfilling processes beneath submarine pipelines. For this purpose, we aim to simplify the experimental backfilling process to an elementary two...

  13. Use of Dilute Flowable Backfill for Corrosion Mitigation of Buried Pipe

    Science.gov (United States)

    2010-02-01

    Engineers Engineer Research & Development Center Construction Engineering Research Laboratory Flowable Backfill Design Specifications Mix Composition ...US Army Corps of Engineers Engineer Research & Development Center Construction Engineering Research Laboratory Use of Dilute Flowable Backfill for...1. REPORT DATE FEB 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Use of Dilute Flowable Backfill for

  14. The Buffer and Backfill Handbook. Part 3: Models for calculation of processes and behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Geodevelopment AB, Lund (Sweden)

    2003-01-15

    nature. They are coupled to other processes and affected by various restrictions such as limited access to water and transient interaction with dissolved species. This makes the issue of coupled models very important but almost all the models and codes that are being used in predicting the behaviour of buffers and backfills in a repository are simplified and incomplete with respect to the hydrothermal processes. This is because of the lack of understanding of the involved physico-chemical mechanisms, for which consideration of the behaviour of the clay on the microstructural level is required. Chapter 3 deals with microstructural issues focusing on particle interaction and void distribution in buffers and backfills with special respect to swelling pressure and permeation of fluids and gas. Chapter 4 deals with heat transport in fully and partly water saturated buffer clays. It includes mathematical formulation of empirically deduced material models of heat conductivity and gives examples of how this quantity can be evaluated from laboratory experiments. Chapter 5 deals with flow of water in liquid and vapour form in fully and partly water saturated buffers and backfills. The presented material models are intended for practical use and imply that potential theory in the form of Navier/Stoke's laws for analytical solution or numerical methods are valid. Chapter 6 gives the basis of currently used material models for anion and cation diffusion through smectitic soil. Complexation may cause considerable deviation from theoretically derived migration rates and only diffusive transport of species that do not undergo chemical reactions is treated here. Focus is on outlining the formulation of theoretical models for evaluation of diffusion coefficients from controlled experiments. As for water transport, the solution of practical 2 and 3D problems is made by use of potential theory, applying analytical or numerical techniques, which are not treated here. Chapter 7 deals

  15. 30 CFR 819.19 - Auger mining: Backfilling and grading.

    Science.gov (United States)

    2010-07-01

    ... of the highwall shall be stable and not pose a hazard to the public health and safety or to the... health and safety or to the environment. ... authority that the backfill, designed by a qualified registered professional engineer, has a minimum...

  16. 30 CFR 816.102 - Backfilling and grading: General requirements.

    Science.gov (United States)

    2010-07-01

    ..., acid- and toxic-forming materials, and combustible materials exposed, used, or produced during mining.... 816.102 Section 816.102 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT...-SURFACE MINING ACTIVITIES § 816.102 Backfilling and grading: General requirements. (a) Disturbed...

  17. 30 CFR 817.102 - Backfilling and grading: General requirements.

    Science.gov (United States)

    2010-07-01

    .... 817.102 Section 817.102 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT...-UNDERGROUND MINING ACTIVITIES § 817.102 Backfilling and grading: General requirements. (a) Disturbed areas... leaching of toxic materials. (d) Spoil may be placed on the area outside the mined-out surface area...

  18. Backfilling of KBS-3V deposition tunnels - possibilities and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Wimelius, Hans (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Pusch, Roland (Geodevelopment International AB, Lund (Sweden))

    2008-12-15

    By definition for the SKB repository concept, the backfill of KBS-3V deposition tunnels must be so designed that transport of dissolved matter is controlled by diffusion and not by advective water flow. This requires that the hydraulic conductivity of the backfill does not exceed about E-10 m/s. The backfilling materials also have to adequately resist compression caused by upward expansion of the buffer. It must also exert an effective pressure of at least 100 kPa on the rock in order to provide support to the rock and minimize spalling of the rock. These criteria are fulfilled by several approaches and options for backfill materials, placed and compacted layer wise or in the form of blocks of compacted clay powder. Based on the experience from comprehensive lab studies and considering practical issues, SKB has selected a concept where the major part of the backfill consists of stacked blocks that are surrounded by clay pellets. Using this concept a basis for a detailed evaluation, a study of three different techniques for placing the blocks has been undertaken. The three block placement techniques examined are the 'Block', 'Robot', and 'Module' methods. They involve different block sizes and techniques for handling and placing the blocks but the same way of preparing the foundation bed of the blocks and placing the pellet filling. The blasted tunnels have a varying cross section, caused by the orientation of the blast-holes. This requires that a varying fraction of blocks be installed in the backfilling along the blasted tunnel interval if sufficiently high density and low hydraulic conductivity is to be achieved. The efficiency of filling will depend on the type of clay used in the blocks. For example, using Friedland clay for block preparation, the filling efficiency must be 80% while it can be reduced to 60% if more smectite-rich clay is used. The use of a clay with high smectite content increases margins and is concluded to be

  19. The Buffer and Backfill Handbook. Part 3: Models for calculation of processes and behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Geodevelopment AB, Lund (Sweden)

    2003-01-15

    nature. They are coupled to other processes and affected by various restrictions such as limited access to water and transient interaction with dissolved species. This makes the issue of coupled models very important but almost all the models and codes that are being used in predicting the behaviour of buffers and backfills in a repository are simplified and incomplete with respect to the hydrothermal processes. This is because of the lack of understanding of the involved physico-chemical mechanisms, for which consideration of the behaviour of the clay on the microstructural level is required. Chapter 3 deals with microstructural issues focusing on particle interaction and void distribution in buffers and backfills with special respect to swelling pressure and permeation of fluids and gas. Chapter 4 deals with heat transport in fully and partly water saturated buffer clays. It includes mathematical formulation of empirically deduced material models of heat conductivity and gives examples of how this quantity can be evaluated from laboratory experiments. Chapter 5 deals with flow of water in liquid and vapour form in fully and partly water saturated buffers and backfills. The presented material models are intended for practical use and imply that potential theory in the form of Navier/Stoke's laws for analytical solution or numerical methods are valid. Chapter 6 gives the basis of currently used material models for anion and cation diffusion through smectitic soil. Complexation may cause considerable deviation from theoretically derived migration rates and only diffusive transport of species that do not undergo chemical reactions is treated here. Focus is on outlining the formulation of theoretical models for evaluation of diffusion coefficients from controlled experiments. As for water transport, the solution of practical 2 and 3D problems is made by use of potential theory, applying analytical or numerical techniques, which are not treated here. Chapter 7 deals

  20. Effect of Initial Backfill Temperature on the Deformation Behavior of Early Age Cemented Paste Backfill That Contains Sodium Silicate

    Directory of Open Access Journals (Sweden)

    Aixiang Wu

    2016-01-01

    Full Text Available Enhancing the knowledge on the deformation behavior of cemented paste backfill (CPB in terms of stress-strain relations and modulus of elasticity is significant for economic and safety reasons. In this paper, the effect of the initial backfill temperature on the CPB’s stress-strain behavior and modulus of elasticity is investigated. Results show that the stress-strain relationship and the modulus of elasticity behavior of CPB are significantly affected by the curing time and initial temperature of CPB. Additionally, the relationship between the modulus of elasticity and unconfined compressive strength (UCS and the degree of hydration was evaluated and discussed. The increase of UCS and hydration degree leads to an increase in the modulus of elasticity, which is not significantly affected by the initial temperature.

  1. Backfilling of KBS-3V deposition tunnels - possibilities and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Wimelius, Hans (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Pusch, Roland (Geodevelopment International AB, Lund (Sweden))

    2008-12-15

    By definition for the SKB repository concept, the backfill of KBS-3V deposition tunnels must be so designed that transport of dissolved matter is controlled by diffusion and not by advective water flow. This requires that the hydraulic conductivity of the backfill does not exceed about E-10 m/s. The backfilling materials also have to adequately resist compression caused by upward expansion of the buffer. It must also exert an effective pressure of at least 100 kPa on the rock in order to provide support to the rock and minimize spalling of the rock. These criteria are fulfilled by several approaches and options for backfill materials, placed and compacted layer wise or in the form of blocks of compacted clay powder. Based on the experience from comprehensive lab studies and considering practical issues, SKB has selected a concept where the major part of the backfill consists of stacked blocks that are surrounded by clay pellets. Using this concept a basis for a detailed evaluation, a study of three different techniques for placing the blocks has been undertaken. The three block placement techniques examined are the 'Block', 'Robot', and 'Module' methods. They involve different block sizes and techniques for handling and placing the blocks but the same way of preparing the foundation bed of the blocks and placing the pellet filling. The blasted tunnels have a varying cross section, caused by the orientation of the blast-holes. This requires that a varying fraction of blocks be installed in the backfilling along the blasted tunnel interval if sufficiently high density and low hydraulic conductivity is to be achieved. The efficiency of filling will depend on the type of clay used in the blocks. For example, using Friedland clay for block preparation, the filling efficiency must be 80% while it can be reduced to 60% if more smectite-rich clay is used. The use of a clay with high smectite content increases margins and is concluded to be

  2. Backfilling technology and strata behaviors in fully mechanized coal mining working face

    Institute of Scientific and Technical Information of China (English)

    Zhang Qiang; Zhang Jixiong; Huang Yanli; Ju Feng

    2012-01-01

    Based on the principle of fully mechanized backfilling and coal mining technology and combined with theXingtai Coal Mine conditions,we mainly optimized the coal mining equipment and adjusted the coal mining method in the Xingtai Coal Mine 7606 working face for implementation this technology,Firstly,we define the practical backfilling process as the "(from backfilling scraper conveyor's) head to tail backfilling,step by step swinging up of the tamping arm.gradual compacting,moving formed backfilling scraper conveyor when the second tamping arm cannot pass and connecting the immediate roof by back material push front material movement".Meanwhile,the stress changes of backfill body in coal mined out area was monitored by stress sensors,and the roof caving law was analyzed by monitoring the dynamic subsidence of -210 west roadway of this face.The site tests results show that using this new backfilling and coal mining integrated technology,the production capacity in the 7606 working face can reach to 283,000 ton a year,and 282,000 ton of solid materials (waste and fly ash) is backfilled,which meets the needs of high production and efficiency.The goaf was compactly backfilled with solid material and the strata behavior was quite desirable,with an actual maximum vertical stress of the backfill body of 5.5 MPa.Backfill body control the movement of overburden within a certain range,and there is no collapses of major areas in the overlying strata upon backfilled gob.The maximum subsidence and speed were 231 mm and 15.75 mm/d respectively,which proved the practical significance of this integrated technology.

  3. Radon emanation from backfilled mill tailings in underground uranium mine.

    Science.gov (United States)

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekananda; Patnaik, R Lokeswara; Sethy, Narendra Kumar

    2014-04-01

    Coarser mill tailings used as backfill to stabilize the stoped out areas in underground uranium mines is a potential source of radon contamination. This paper presents the quantitative assessment of radon emanation from the backfilled tailings in Jaduguda mine, India using a cylindrical accumulator. Some of the important parameters such as (226)Ra activity concentration, bulk density, bulk porosity, moisture content and radon emanation factor of the tailings affecting radon emanation were determined in the laboratory. The study revealed that the radon emanation rate of the tailings varied in the range of 0.12-7.03 Bq m(-2) s(-1) with geometric mean of 1.01 Bq m(-2) s(-1) and geometric standard deviation of 3.39. An increase in radon emanation rate was noticed up to a moisture saturation of 0.09 in the tailings, after which the emanation rate gradually started declining with saturation due to low diffusion coefficient of radon in the saturated tailings. Radon emanation factor of the tailings varied in the range of 0.08-0.23 with the mean value of 0.21. The emanation factor of the tailings with moisture saturation level over 0.09 was found to be about three times higher than that of the absolutely dry tailings. The empirical relationship obtained between (222)Rn emanation rate and (226)Ra activity concentration of the tailings indicated a significant positive linear correlation (r = 0.95, p radon emanation rate from the backfill material of similar nature.

  4. Effects of grouting, shotcreting and concrete leachates on backfill geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Miguel; Arcos, David; Duro, Lara [Enviros Consulting, Valldoreix, Barc elona (Spain)

    2007-11-15

    The use of concrete to seal open fractures (grouting) and to impermeabilise the deposition tunnels (shotcreting) has been envisaged in the construction of a high level nuclear waste (HLNW) repository according to SKB designs. Nevertheless, the geochemical effect of using concrete in the repository is not fully understood. Concrete degradation due to the interaction with groundwater can affect the performance of other repository barriers, such as the backfill material used for sealing the deposition tunnels. One of the main effects of concrete degradation is the generation of alkaline plumes. For this reason, SKB is currently planning to use a type of concrete whose degradation result in lower pH values than those developed with Ordinary Portland Cement (OPC). In order to assess the long-term geochemical effect of including low-pH concrete elements in a HLNW repository, we performed a 2D reactive-transport model of a backfilled deposition tunnel that intersects a hydraulic conductive fracture which has been partially grouted. An additional case has been modelled where part of the deposition tunnel walls were covered with a shotcrete layer. The modelling results predict the development of a high-alkalinity plume, larger in the case of considering a grouted fracture, accompanied by the precipitation of CSH-phases in the fracture. However, the effect on the backfill material is only significant if concrete is in contact with the backfill (shotcrete case). In order to conduct these models, and considering that at the beginning of the present work there was not a specific composition for such a low-pH concrete, its composition has been assumed in order to meet the expected geochemical evolution of concrete degradation according to SKB expectations. This is a pH of pore water of around 11 and the degradation of CSH phases resulting in a source for Ca and Si into the system. For this reason, jennite and tobermorite have been selected, although it is known that jennite is

  5. Mechanical analysis of roof stability under nonlinear compaction of solid backfill body

    Institute of Scientific and Technical Information of China (English)

    Li Meng⇑; Zhang Jixiong; Liu Zhan; Zhao Xu; Huang Peng

    2016-01-01

    Based on the compaction characteristic test and the nonlinear compaction deformation characteristics of backfill material, this paper applies the theory of nonlinear elastic foundation of thin plate to establish a mechanical model of backfill body and roof in solid dense backfill coal mining. This study critically anal-yses the deflection equation of the roof by the energy method, derives the conditions of roof breakage and combined with concrete engineering practice analyses, determines roof movement regularity and stabil-ity in solid dense backfill mining. Analysis of the engineering practice of the 13,120 backfill panel of Pingmei 12# mine shows the theoretical maximum of roof convergence in backfill mining to be 415 mm which is in significant agreement with the measured value. During the advancing process of solid backfill mining at the panel, the maximum tensile stress on the roof is less than its tensile strength which does not satisfy the conditions for roof breakage. Drilling results on the roof and ground pressure monitoring show that the integrity of roof is strong, which is consistent with the theoretical calculations described in this study. The results presented in the study provide a basis for further investigation into strata movement theory in solid dense backfill mining.

  6. 30 CFR 816.106 - Backfilling and grading: Previously mined areas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Backfilling and grading: Previously mined areas...-SURFACE MINING ACTIVITIES § 816.106 Backfilling and grading: Previously mined areas. (a) Remining... opertions where the volume of all reasonably available spoil is demonstrated in writing to the...

  7. 30 CFR 817.106 - Backfilling and grading: Previously mined areas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Backfilling and grading: Previously mined areas...-UNDERGROUND MINING ACTIVITIES § 817.106 Backfilling and grading: Previously mined areas. (a) Remining... operations where the volume of all reasonably available spoil is demonstrated in writing to the...

  8. Particle Flow Characteristics and Transportation Optimization of Superfine Unclassified Backfilling

    Directory of Open Access Journals (Sweden)

    Ke-ping Zhou

    2017-01-01

    Full Text Available In order to investigate the high volume fraction problem of the solid phase in superfine unclassified backfilling pipeline transportation, characteristic parameters were obtained by fitting to test data with an R–R particle size distribution function; then, a Euler dense-phase DPM (Discrete phase model model was established by applying solid–liquid two-phase flow theory and the kinetic theory of granular flow (KTGF. The collision and friction of particles were imported by the UDF (User-define function function, and the pipeline fluidization system, dominated by interphase drag forces, was analyzed. The best concentration and flow rate were finally obtained by comparing the results of the stress conditions, flow field characteristics, and the discrete phase distributions. It is revealed that reducing the concentration and flow rate could control pressure loss and pipe damage to a certain degree, while lower parameters show negative effects on the transportation integrity and backfilling strength. Indoor tests and field industrial tests verify the reliability of the results of the numerical simulations. Research shows that the model optimization method is versatile and practical for other, similar, complex flow field working conditions.

  9. The Buffer and Backfill Handbook. Part 1: Definitions, basic relationships and laboratory methods

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Geodevelopment AB, Lund (Sweden)

    2002-04-01

    Part 1 of this Handbook is focused on description of fundamental issues of soil physical and chemical arts and on soil mechanical definitions and relationships. Part 2 comprises a material data basis including also preparation and field testing methods. Part 3 provides a collection of physical and mathematical models and examples of how they can and should be applied. The present document, which has been prepared by Geodevelopment AB in co-operation with Scandia Consult AB and Clay Technology AB, Sweden, and with TVO, Finland, makes up Part 1. Most of the data and information emanate from the work that Geodevelopment AB and Clay Technology AB have performed for SKB but a number of results from experiments made in and for other organizations have been included as well. A significant number of experimental procedures and ways of characterizing buffers and backfills are included. The experience from the comprehensive international Stripa Project, concerning both systematic material investigations in the laboratory and the full-scale field experiments, has contributed significantly to this report. However, similar and additional information gained from later work in SKB's Aespoe Hard Rock Laboratory and from NAGRA and also from other waste-isolation projects have helped to make this document of assumed international interest.

  10. Design and application of solid, dense backfill advanced mining technology with two pre-driving entries

    Institute of Scientific and Technical Information of China (English)

    Zhang Qiang; Zhang Jixiong; Guo Shuai; Gao Rui; Li Weikang

    2015-01-01

    New solid backfill mining technology provides unique technical advantages for‘three-under’ coal min-ing which refers to coal resources trapped under buildings, railways, and water bodies. This technology has a much higher recovery rate and can effectively control the surface subsidence. However, successful application of this technology depends heavily on geological conditions. To avoid the disadvantages asso-ciated with downward mining and overhead backfilling with this new technology, a new advanced solid backfill mining design with two pre-driving entries is proposed here to ensure the backfill effect. Taking Huayuan coal mine as an example, this paper tests the double gob-side entries retaining with no pillar left scheme and optimizes an integrated technology setup for backfill mining and gob-side entry retain-ing. Field applications show that the recovery rate increased from 40%for strip mining to 85%for backfill mining. Moreover, the new backfill technology allowed for better control over the surrounding rock deformation caused by the gob-side entry retaining effect and better control of ground subsidence as compared to strip mining.

  11. Research on U-steel yieldable support with backfill technology in rock roadway

    Institute of Scientific and Technical Information of China (English)

    LUO Yong; CHANG Ju-cai

    2009-01-01

    The loading on U-steel yieldable support cannot be organically combined with the law of strata behaviors from the surrounding rocks of roadway. In order to effectively solve the problem, U-steel yieldable support with backfill material and the performance requirements of backfill material were analyzed on the basis of structural mechanics. The mechanical properties of backfill material selected were tested in the laboratory, and the test results show that the ratio of the backfill material complies with the requirements of backfill technology; it can effectively optimize the relationship between the support and the surrounding rock, and the filling layer can avoid the partial stress concentration and fully improve the support performance. Compared with U-steel yieldable support with gangue filling, the filed application shows that the supporting result of U-steel yieldable support with backfill technology is satisfactory, the stress on U-steel yieldable support with backfill technology decreases greatly and distributes uniformly, convergence of the surrounding rock of roadway is decreased by more than 50%, and the surrounding rocks of roadway are controlled effectively.

  12. Research on U-steel yieldable support with backfill technology in rock roadway

    Energy Technology Data Exchange (ETDEWEB)

    Yong Luo; Ju-cai Chang [Huainan Mining Group Co. Ltd., Huainan (China). Postdoctoral Scientific Research Station

    2009-12-15

    The loading on U-steel yieldable support cannot be organically combined with the law of strata behaviors from the surrounding rocks of roadway. In order to effectively solve the problem, U-steel yieldable support with backfill material and the performance requirements of backfill material were analyzed on the basis of structural mechanics. The mechanical properties of backfill material selected were tested in the laboratory, and the test results show that the ratio of the backfill material complies with the requirements of backfill technology; it can effectively optimize the relationship between the support and the surrounding rock, and the filling layer can avoid the partial stress concentration and fully improve the support performance. Compared with U-steel yieldable support with gangue filling, the filed application shows that the supporting result of U-steel yieldable support with backfill technology is satisfactory, the stress on U-steel yieldable support with backfill technology decreases greatly and distributes uniformly, convergence of the surrounding rock of roadway is decreased by more than 50%, and the surrounding rocks of roadway are controlled effectively.

  13. Realizing of Optimization of Binder Backfill Material Under Certain Strength with Fuzzy Sets

    Institute of Scientific and Technical Information of China (English)

    崔明义; 胡华

    2001-01-01

    The main factors deciding the compressive strength of binder backfill body are tailing density and binder dosage in binder backfill materials. Based on the antecedent of certain pulp density, the method of increasing the tailing density and reducing the binder dosage, or the manner of cutting down the tailing density and gaining the binder dosage are taken to guarantee the strength of backfill body. The problem that should be solved is how to determine the tailing density and the binder dosage rationally. This paper tries to realize the correct selection of the tailing density and the binder dosage in computer with the method of fuzzy mathematics.

  14. FY:15 Transport Properties of Run-of-Mine Salt Backfill ? Unconsolidated to Consolidated.

    Energy Technology Data Exchange (ETDEWEB)

    Dewers, Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Heath, Jason E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Leigh, Christi D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-28

    The nature of geologic disposal of nuclear waste in salt formations requires validated and verified two-phase flow models of transport of brine and gas through intact, damaged, and consolidating crushed salt. Such models exist in other realms of subsurface engineering for other lithologic classes (oil and gas, carbon sequestration etc. for clastics and carbonates) but have never been experimentally validated and parameterized for salt repository scenarios or performance assessment. Models for waste release scenarios in salt back-fill require phenomenological expressions for capillary pressure and relative permeability that are expected to change with degree of consolidation, and require experimental measurement to parameterize and validate. This report describes a preliminary assessment of the influence of consolidation (i.e. volume strain or porosity) on capillary entry pressure in two phase systems using mercury injection capillary pressure (MICP). This is to both determine the potential usefulness of the mercury intrusion porosimetry method, but also to enable a better experimental design for these tests. Salt consolidation experiments are performed using novel titanium oedometers, or uniaxial compression cells often used in soil mechanics, using sieved run-of-mine salt from the Waste Isolation Pilot Plant (WIPP) as starting material. Twelve tests are performed with various starting amounts of brine pore saturation, with axial stresses up to 6.2 MPa (~900 psi) and temperatures to 90°C. This corresponds to UFD Work Package 15SN08180211 milestone “FY:15 Transport Properties of Run-of-Mine Salt Backfill – Unconsolidated to Consolidated”. Samples exposed to uniaxial compression undergo time-dependent consolidation, or creep, to various degrees. Creep volume strain-time relations obey simple log-time behavior through the range of porosities (~50 to 2% as measured); creep strain rate increases with temperature and applied stress as expected. Mercury porosimetry

  15. Groundwater flow evaluation through backfilling materials of a surface coal mining site of Northeast Mexico

    Science.gov (United States)

    Gutierrez-Ojeda, C.; Martínez-Morales, M.; Ortíz-Flores, G.

    2013-05-01

    Surface coal mining at the Allende-Piedras Negras aquifer system requires the complete dewatering and removal of the aquifer. The aquifer contains several geologic layers of variable hydraulic conductivity. Backfilling material is composed of a mixture of permeable and impermeable layers and it was initially considered as impermeable. Exploratory drillings, pumping tests and a geophysical survey were performed in the backfilling materials and the surrounding unaltered materials in order to evaluate the natural groundwater flow modification due to the mining activities. Results of geophysical survey evidenced a saturated water table within the back filling material which was verified by exploratory drilling. Pumping tests showed that unaltered materials have a mean hydraulic conductivity of 34.5 m/day while the backfilling of 5.3 m/day. Although the mining activities reduce the hydraulic conductivity by almost an order of magnitude, it was corroborated the existence of a groundwater flow through the backfilling materials.

  16. Effects of bituminous layer as backfill material on mechanical behavior in tunnel model

    OpenAIRE

    Moriyoshi, Akihiro; Takano, Shin-ei; Urata, Hiroyuki; Suzuki, Tetsuya; Yoshida, Takaki

    2001-01-01

    This paper describes the effects of bituminous material as a backfill material on mechanical behavior in model tunnel in laboratory. It is known that load spreading and relaxation of bituminous material are good properties. Then if we use bituminous material as a backfill material of tunnel, the tunnel will have waterproof, good load spreading property. We used new bituminous material (Aquaphalt) which can solidify in water. We conducted relaxation test in tension for new bituminous mat...

  17. REQUIREMENT OF FLUIDITY OF HIGH WATER CONTENT MATERIALS FORTHE GETWAY-SIDE BACKFILLING TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    QiTaiyue; MaNianjie

    1996-01-01

    Through analyzing the effects of water consumption, diameter of solid particle, and flow velocity on the fluidity of high water content material slurry, the relationship among the fluidity, the isotropy of the slurry, and the pumping facilities applied in getway-side backfilling has been found. And the requirment of fluidity of high water content material for the design of getway-side backfilling technique is put forward in the paper.

  18. Design, production and initial state of the backfill and plug in deposition tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Boerjesson, Lennart; Gunnarsson, David; Johannesson, Lars-Erik; Jonsson, Esther

    2010-12-15

    The report is included in a set of Production reports, presenting how the KBS-3 repository is designed, produced and inspected. The set of reports is included in the safety report for the KBS-3 repository and repository facility. The report provides input on the initial state of the backfill and plug in deposition tunnels for the assessment of the long-term safety, SR-Site. The initial state refers to the properties of the engineered barriers once they have been finally placed in the KBS-3 repository and will not be further handled within the repository facility. In addition, the report provides input to the operational safety report, SR-Operation, on how the backfill and plug shall be handled and installed. The report presents the design premises and reference designs of the backfill and plug in deposition tunnels and verifies their conformity to the design premises. It also describes the production of the backfill from excavation and delivery of backfill material to installation in the deposition tunnel, and gives an outline of the installation of the plug. Finally, the initial states of the backfill and plug and their conformity to the reference designs and design premises are presented

  19. Mechanical interaction buffer/backfill. Finite element calculations of the upward swelling of the buffer against both dry and saturated backfill

    Energy Technology Data Exchange (ETDEWEB)

    Boergesson, Lennart (Clay Technology AB, Lund (Sweden)); Hernelind, Jan (5T-Engineering AB, Vaesteraas (Sweden))

    2009-10-15

    The mechanical interaction between the buffer material in the deposition hole and the backfill material in the deposition tunnel is an important process in the safety assessment since the primary function of the backfill is to keep the buffer in place and not allow it to expand too much and thereby loose too much of its density and barrier properties. In order to study the upwards swelling of the buffer and the subsequent density reduction a number of finite element calculations have been performed. The calculations have been done with the FE-program Abaqus with 3D-models of a deposition hole and the deposition tunnel. In order to refine the modelling only the two extreme cases of completely un-wetted (dry) and completely water saturated (wet) backfill have been modelled. For the wet case the influence of different factors has been studied while only one calculation of the dry case has been done. The calculated upwards swelling of the buffer varied between 2 and 15 cm for the different wet cases while it was about 10 cm for the dry case. In the wet reference case the E-modulus of the block and pellets fillings was 50 MPa and 3.24 MPa respectively, the friction angle between the buffer and the rock and canister was 8.7 deg and there were no swelling pressure from the backfill. There is a strong influence of the friction angle on both the upwards swelling and the canister heave. The friction is important for preventing especially canister displacements. The unrealistic case of no friction yielded strong unacceptable influence on the buffer with an upwards swelling of 15 cm and a strong heave of 5 cm of the canister. The influence of the backfill stiffness is as expected strong. Both buffer swelling and canister heave are twice as large at the E-modulus E = 25 MPa than at the E-modulus E = 100 MPa. The influence of the stiffness of the pellets filling is not strong since there are no pellets on the floor in the model used. The influence of the swelling pressure of the

  20. Use of fly ash in backfill at Kidd Creek Mines

    Energy Technology Data Exchange (ETDEWEB)

    Yu, T.R.; Counter, D.B. (Kidd Creek Mines Ltd., Timmins, ON (Canada))

    1988-01-01

    In an effort to increase productivity, the use of fly ash from thermal power plants as a binder for consolidated backfill was studied. From laboratory and underground tests for its cementitious properties and environmental effects, it was found that a portion of Portland cement could be replaced by the same amount of type C fly ash (produced from subbituminous coal or lignite) to produce an acceptable consolidated rockfill product for use at an Ontario mine. The environmental concerns in terms of dust control and emanation of radon gas were unfounded from measurements. The dust count was comparable to the use of Portland cement only, or with ground blast furnance slag, and the radiation readings were low, averaging one-seventh the regulation level. Since May 1984, a total of over 100,000 tonnes of fly ash has been consumed as a binder blended with Portland cement, producing over four million tonnes of consolidated rockfill. To date, the fill in the stopes has performed very satisfactorily, while yielding considerable cost savings. 9 refs.

  1. Dessicant materials screening for backfill in a salt repository

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, D.R.

    1980-10-01

    Maintaining an anhydrous environment around nuclear waste stored in a salt repository is a concern which can be alleviated by using a desiccant material for backfilling. Such a desiccant should desiccate a brine yet be non deliquescent, the hydrated product should have moderate thermal stability, and the desiccant should have a high capacity and be readily available. From a literature search MgO and CaO were identified for detailed study. These oxides, and an intimate mixture of the two obtained by calcining dolomite, were used in experiments to further determine their suitability. They proved to be excellent desiccants with a high water capacity. The hydrates of both have moderate thermal stability and a high water content. Both MgO and CaO react in an alkaline chloride brine forming oxychloride compounds with different waters of crystallization. Some of these compounds are the Sorel Cements. CaO hydrates to Ca(OH)/sub 2/ which carbonates with CO/sub 2/ in air to form CaCO/sub 3/ and release the hydrated water. Thus the intimate mixture of CaO and MgO from calcined dolomite may serve as a desiccant and remove CO/sub 2/ from the repository atmosphere.

  2. Optimization of backfill pellet properties AASKAR DP2 - Laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Linus; Sanden, Torbjoern [Clay Technology AB, Lund (Sweden)

    2012-12-15

    Bentonite pellets are planned to be used as a part of the backfill in the Swedish spent nuclear fuel deep repository concept KBS-3. This report describes testing and evaluation of different backfill pellet candidates. The work completed included testing of both pellet material and pellet type. The materials tested were sourced from India (ASHA), Greece (IBECO, 2 products) and Wyoming USA (MX-80 clay). The majority of the tests were completed on the ASHA clay as well as the IBECO-RWC-BF products, with only limited testing of the others. The pellets tested were manufactured using both extrusion and roller compaction techniques and had different sizes and geometries. The following tests have been performed and are presented in this report: 1. General tests. Water content, bulk density and dry density have been determined for both the pellet filling and the individual pellets. The compressibility of the pellet filling was tested with CRS-tests and the strength of the individual pellets was tested with a special compression test. The water content varied from 11.3% to 18.7% and was highest for the extruded pellets. The dry density was somewhat higher for the roller-compacted pellets and their compressibility was lower. The strength of the individual pellets was generally higher for the extruded pellets. 2. Erosion. The pellet filling will be exposed to groundwater inflow when installed in the tunnel. This flow could possibly cause significant erosion on the pellet filling. Erosion tests have been performed with comparisons in erosion resistance made on the various material- and pellet-types. The influence of variations in water salinity and flow rates was also tested. The IBECO extruded 6- and 10- mm diameter rods and the compacted Posiva spec.-A pellet filling seem to have the lowest tendency to erode. It is also the IBECO extruded pellet filling that withstands variations in water salinity and flow rates best. 3. Water storing capacity. The pellet filling

  3. Vertical transportation system of solid material for backfilling coal mining technology

    Institute of Scientific and Technical Information of China (English)

    Ju Feng; Zhang Jixiong; Zhang Qiang

    2012-01-01

    For transportation of solid backfill material such as waste and fly ash from the surface to the bottom of the shaft in a fully mechanized backfilling coal backfilling coal mining technology,we developed a new vertical transportation system to transport this type of solid backfill material.Given the demands imposed on safely in feeding this material,we also investigated the structure and basic parameter of this system.For a mine in the Xingtai mining area the results show that:(1) a vertical transportation system should include three main parts,i.e.,a feeding borehole,a maintenance chamber and a storage silo; (2) we determined that 486 mm is a suitable diameter for bore holes,the diameter of the storage silo is 6 m and its height 30 m in this vertical transportation system; (3) a conical buffer was developed to absorb the impact during the feeding process.To ensure normal implementation of fully mechanized backfilling coal mining technology and the safety of underground personnel,we propose a series of security technologies for anti-blockage,storage silo cleaning.high pressure air release and aspiration.This vertical transporting system has been applied in one this particular mine,which has fed about 4 million tons solid material with a feeding depth of 350 m and safely exploited 3 million tons of coal.

  4. Design and construction of the backfilled pit cover system at Whistle Mine, Canada : a case study

    Energy Technology Data Exchange (ETDEWEB)

    Ayres, B.K.; O' Kane, M. [O' Kane Consultants Inc., Saskatoon, SK (Canada); Lanteigne, L. [Inco Ltd., Sudbury, ON (Canada)

    2005-07-01

    This paper describes the design and construction of an engineered cover system developed during the decommissioning of Inco's Whistle Mine in Sudbury, Ontario. The process involved the relocation of 6.4 million tonnes of acid-generating waste rock to the open pit from 2 adjacent stockpiles. The cover system, which works as a barrier to minimize the entry of atmospheric oxygen and water to the underlying material, was developed for backfilling the pit to reduce acid-rock drainage. The effectiveness of a range of cover systems was determined through geochemical modelling. Field trials were also conducted at the site to monitor the performance of the cover system and to estimate full-scale construction costs. A calibrated model of covered waste rock was developed using the VADOSE/W two-dimensional soil-atmosphere model and field data. Net percolation and oxygen infiltration through various cover system alternatives were predicted for site-specific climate conditions. The runoff management and final landform for the pit cover system was determined through erosion and landform evolution numerical modelling. The long-term performance of the pit cover system is affected by physical process such as erosion, slope instability, wet-dry cycles, freeze-thaw cycles, consolidation, extreme climate events and brush fires. Efforts were made to minimize the chemical processes that affect liner performance such as osmotic consolidation, dispersion, dissolution, acidic hydrolysis, mineralogical consolidation, sorption, salinization and oxidation. It was noted that the performance of the liner is also influenced by biological processes such as root penetration, burrowing animals, bioturbation, human intervention, bacteriological clogging and the establishment of vegetation. 12 refs., 2 tabs., 10 figs.

  5. Effect of localized water uptake on backfill hydration and water movement in a backfilled tunnel: half-scale tests at Aespoe Bentonite Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D. [Atomic Energy of Canada Limited, Chalk River (Canada); Jonsson, E. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hansen, J. [Posiva Oy, Olkiluoto (Finland); Hedin, M. [Aangpannefoereningen, Stockholm (Sweden); Ramqvist, G. [Eltekno AB, Figeholm (Sweden)

    2011-04-15

    The report describes the outcome of the work within the project 'SU508.20 Impact of water inflow in deposition tunnels'. Project decision SKB doc 1178871 Version 3.0. Two activity plans have been used for the field work: AP TD SU50820-09-019 and AP TD SU 50820-09-071. SKB and Posiva have been examining those processes that may have particularly strong effects on the evolution of a newly backfilled deposition tunnel in a KBS-3V repository. These assessments have involved the conduct of increasingly large and complex laboratory tests and simulations of a backfilled tunnel section. In this series of four tests, the effect of water inflow into a backfilled tunnel section via an intersecting fracture feature was evaluated. The tests included the monitoring of mock-ups where water entered via the simulated fractures as well as evaluation of what the effect of isolated tunnel sections caused by localized water inflow would have on subsequent evolution of these isolated sections. It was found that even a slowly seeping fracture can have a substantial effect on the backfill evolution as it will cause development of a gasket-like feature that effectively cuts of air and water movement from inner to outer regions of the backfilled tunnel. Water entering via these fractures will ultimately move out of the tunnel via a single discrete flow path, in a manner similar to what was observed in previous 1/2-scale and smaller simulations. If the low-rate of water inflow from fracture is the only source of water inflow to the tunnel this will result in hydraulic behaviour similar to that observed for a single inflow point in previous tests. The presence of a fracture feature will however result in a larger proportion of water uptake by the process of suction than might occur in a point inflow situation and hence a more uniform water distribution will be present in the pellet fill. This also results in a greater tendency for water to be absorbed into the adjacent block fill

  6. The repair of ground cover of Bolivia-Brazil gas pipeline near Paraguay River crossing, in a swamp soft soil region, using geo synthetics reinforced backfilling; Reparo da cobertura do gasoduto Bolivia-Brasil junto ao Rio Paraguai, em trecho com solo mole, utilizando aterro reforcado com geosinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Cesar Augusto; Jorge, Kemal Vieira; Bechuate Filho, Pedro [TBG - Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Campo Grande, MS (Brazil). Gerencia Regional Centro Oeste (CRGO); Teixeira, Sidnei H.C. [Geohydrotech Engenharia S.C. Ltda., Braganca Paulista, SP (Brazil)

    2005-07-01

    TBG - Transportadora Gasoduto Bolivia-Brasil S.A, executes routine maintenance works at the Gas Pipeline Right of Way, seeking its integrity. In the wetlands of Pantanal, near the Paraguay river crossing, the organic-alluvial soil was submitted to the process of subsidence. This process, associated with the river water flow erosion, shrank the soil volume and diminished or extinguished the pipeline land cover. The pipeline was exposed to the environment, and submitted to tension stresses and the risk of low cycle fatigue during the floods. The cathodic protection system also had to be evaluated, specially in the drought. To mitigate the problem, the embankment technique was adopted using sandy soil, reinforced with polyester geo-webs and with woven polipropene geo-textiles. The solution also used geo-webs with soil-cement as protection elements against the degradation of the geo-textiles blankets. Some monitoring works are associated with those interventions: monitoring of cathodic protection; topographical verification of horizontal and vertical displacements of the pipeline; levels of land covering, and rainfalls and flood measurement. The base of the embankment was built with hydraulic transported soil, and at the end consistently supported the gas pipeline. (author)

  7. Study on Key Technology of Using Shell Sand as Backfill for Sea Reclamation

    Institute of Scientific and Technical Information of China (English)

    LI Neng-hui; QU Yi-rong; HE Wen-qin; CHEN Hui

    2005-01-01

    The results of a study on the key technology of using shell sand, a kind of sea sand, as backfill for sea reclamation are described briefly. Laboratory tests show that the physical and mechanical properties of shell sand are as good as normal quartz sand. Based on the chemical test and durability test of shell sand it could be concluded that the influence of corrosion of shell sand by acid rain and sea water might be ignored in the evaluation of the safety and durability of the engineering project. The results of field improvement tests show that the bearing capacity of shell sand backfill foundation is more than 200 kPa after vibroflotation improvement or dynamic compaction improvement. The shell sand is a good backfill material for sea reclamation.

  8. Overlying strata movement of recovering standing pillars with solid backfilling by physical simulation

    Institute of Scientific and Technical Information of China (English)

    An Baifu; Miao Xiexing; Zhang Jixiong; Ju Feng; Zhou Nan

    2016-01-01

    To analyze the overlying strata movement law of recovering room mining standing pillars with solid backfilling. Physical simulation experiments with sponge and wood as the backfilling simulation material were tested. The results show that: (i) The covering-rock mechanics of the overly strata comes from‘two-arch structures+hinged girder+bend beam”to‘backfilling material+hinged girder+bent beam”by increasing the fill ratio from 0%to 85%, the beginning of overlying strata movement appears later and the total duration of subsidence velocity increased from zero to the highest value increases. The trend of‘single polarization” of the subsidence velocity curves becomes noticeable and the velocity variation trend becomes stable. (ii) The equiponderate aeolian sand was added to improve the anti-pressure ability of the loess, and the corresponding ground processing&transportation system was designed.

  9. Valorization of mining waste and tailings through paste backfilling solution, Imiter operation, Morocco

    Institute of Scientific and Technical Information of China (English)

    Khaldoun Abdelhadi; Ouadif Latifa; Baba Khadija; Bahi Lahcen

    2016-01-01

    Mine waste and process tailings storage is one of important challenge for which mining operations are increasingly confronted. Treatment discharges of plants and main part of waste rock development are generally stored on surface areas. The volume and chemical characteristics of these materials generate serious problem for required storage spaces and mainly environmental degradation. Paste backfill (PBF) is one of ingenious solutions to minimize the quantity of tailings to store. PBF is basically defined as a combination of mine processing tailings, binder, and water mixing. The purpose of this paper is to present backfilling components characterization and formula verification for a waste valorization solu-tion through paste backfilling technology in Imiter operation. Obtained results and realized analysis demonstrate PBF conformity and adequacy with assigned underground functions. However the studied recipe can be more ameliorated to obtain an optimal mixture ensuring the required mechanical strength.

  10. A novel silica alumina-based backfill material composed of coal refuse and fly ash.

    Science.gov (United States)

    Yao, Yuan; Sun, Henghu

    2012-04-30

    In this paper, a systematic study was conducted to investigate a novel silica alumina-based backfill material composed of coal refuse and fly ash. The coal refuse and fly ash had different properties under various thermal activation temperatures (20 °C, 150 °C, 350 °C, 550 °C, 750 °C and 950 °C). It is known that a thermal activation temperature ranging from 20 °C to 950 °C significantly increases the flowability and pozzolanic properties of the coal refuse; however, the flowability of fly ash decreases when the activation temperature is higher than 550 °C because of a severe agglomeration phenomenon on its surface. An optimal design for this backfill material was determined to include an activated portion composed of 5% coal refuse at 750 °C and 15% fly ash at 20 °C. This combination yields the best performance with excellent flowability, a high compressive strength and a low bleeding rate. The microanalysis results corresponded well with the performance tests at different activation conditions. In the coal refuse, kaolinite peaks began to decrease because of their transformation into metakaolin at 550 °C. Chlorite peaks disappeared at 750 °C. Muscovite peaks decreased at 750 °C and disappeared at 950 °C. During this process, muscovite 2M(1) gradually dehydroxylated to muscovite HT. Furthermore, this paper examined the environmental acceptance and economic feasibility of this technology and found that this silica alumina-based backfill material composed of coal refuse and fly ash not only meets EPA requirements but also has several advantages in industry feasibility when compared with hydraulic backfill, rock backfill and paste backfill.

  11. Backfill for iliac-crest donor sites: a prospective, randomized study of coralline hydroxyapatite.

    Science.gov (United States)

    Bojescul, John A; Polly, David W; Kuklo, Timothy R; Allen, Thomas W; Wieand, Kay E

    2005-08-01

    We report on a prospective randomized study of coralline hydroxyapatite (CH) used as backfill for iliac-crest donor sites. Autogenous iliac-crest bone graft is routinely harvested for spinal fusion. Donor-site morbidity is underappreciated; the presumption is that donor sites regenerate. In this study, we assessed the biological viability of the backfill CH (Pro OsteonTM Implant 500 Hydroxyapatite Bone Void Filler; Interpore, Irvine, Calif) and compared donor-site morbidity after harvest. Twelve patients (11 men, 1 woman) were enrolled: 5 in the backfill group and 7 in the no-backfill group. As part of routine evaluations done preoperatively and 6 weeks, 3 months, 6 months, and 1 year postoperatively, plain radiographs and computed tomography (CT) scans were used to assess bone ingrowth, and technetium bone scans were used to assess biological activity. Postoperative pain analysis was also done. Ten patients (9 men, 1 woman) completed the study. Of the 4 completers in the backfill group, 3 (75%) showed bony ingrowth on plain radiographs and CT scans at 1 year; the fourth patient showed bony ingrowth only on plain radiographs. All 4 patients showed biological activity on bone scans and reported mild pain to no pain. Of the 6 completers in the no-backfill group, 1 (17%) showed bony ingrowth on plain radiographs and CT scans. No patient showed biological activity on bone scans at 1 year. CH aids in iliac-crest healing after bone-graft harvesting by acting as a biological osteoconductive matrix. Postoperative pain at the bone-graft site is potentially reduced. More studies of larger numbers of patients are needed to assess the true long-term benefits of this material in a clinical setting.

  12. Backfilling of a Scour Hole around a Pile in Waves and Current

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Petersen, Thor Ugelvig; Locatelli, Luca;

    2013-01-01

    This paper presents the results of an experimental investigation of the backfilling of scour holes around circular piles. Scour holes around a pile are generated either by a current or a wave. Subsequently, the flow climate is changed from current to wave, combined waves and current, or wave...... around the pile for the same wave (or combined waves and current) climate. The time scale of backfilling has been determined as a function of three parameters, namely, (1) the Keulegan-Carpenter number of the initial wave or current (which generates the initial scour hole); (2) that of the subsequent...

  13. Borehole Heat Exchanger Systems: Hydraulic Conductivity and Frost-Resistance of Backfill Materials

    Science.gov (United States)

    Anbergen, Hauke; Sass, Ingo

    2016-04-01

    Ground source heat pump (GSHP) systems are economic solutions for both, domestic heating energy supply, as well as underground thermal energy storage (UTES). Over the past decades the technology developed to complex, advanced and highly efficient systems. For an efficient operation of the most common type of UTES, borehole heat exchanger (BHE) systems, it is necessary to design the system for a wide range of carrier fluid temperatures. During heat extraction, a cooled carrier fluid is heated up by geothermal energy. This collected thermal energy is energetically used by the heat pump. Thereby the carrier fluid temperature must have a lower temperature than the surrounding underground in order to collect heat energy. The steeper the thermal gradient, the more energy is transferred to the carrier fluid. The heat injection case works vice versa. For fast and sufficient heat extraction, even over long periods of heating (winter), it might become necessary to run the BHE with fluid temperatures below 0°C. As the heat pump runs periodically, a cyclic freezing of the pore water and corresponding ice-lens growth in the nearfield of the BHE pipes becomes possible. These so called freeze-thaw-cycles (FTC) are a critical state for the backfill material, as the sealing effect eventually decreases. From a hydrogeological point of view the vertical sealing of the BHE needs to be secured at any time (e.g. VDI 4640-2, Draft 2015). The vertical hydraulic conductivity of the BHE is influenced not only by the permeability of the grouting material itself, but by the contact area between BHE pipes and grout. In order to assess the sealing capacity of grouting materials a laboratory testing procedure was developed that measures the vertical hydraulic conductivity of the system BHE pipe and grout. The key features of the procedure are: • assessment of the systeḿs hydraulic conductivity • assessment of the systeḿs hydraulic conductivity after simulation of freeze-thaw-cycle

  14. UNDERGROUNG PLACEMENT OF COAL PROCESSING WASTE AND COAL COMBUSTION BY-PRODUCTS BASED PASTE BACKFILL FOR ENHANCED MINING ECONOMICS

    Energy Technology Data Exchange (ETDEWEB)

    Y.P. Chugh; D. Biswas; D. Deb

    2002-06-01

    This project has successfully demonstrated that the extraction ratio in a room-and-pillar panel at an Illinois mine can be increased from the current value of approximately 56% to about 64%, with backfilling done from the surface upon completion of all mining activities. This was achieved without significant ground control problems due to the increased extraction ratio. The mined-out areas were backfilled from the surface with gob, coal combustion by-products (CCBs), and fine coal processing waste (FCPW)-based paste backfill containing 65%-70% solids to minimize short-term and long-term surface deformations risk. This concept has the potential to increase mine productivity, reduce mining costs, manage large volumes of CCBs beneficially, and improve the miner's health, safety, and environment. Two injection holes were drilled over the demonstration panel to inject the paste backfill. Backfilling was started on August 11, 1999 through the first borehole. About 9,293 tons of paste backfill were injected through this borehole with a maximum flow distance of 300-ft underground. On September 27, 2000, backfilling operation was resumed through the second borehole with a mixture of F ash and FBC ash. A high-speed auger mixer (new technology) was used to mix solids with water. About 6,000 tons of paste backfill were injected underground through this hole. Underground backfilling using the ''Groutnet'' flow model was simulated. Studies indicate that grout flow over 300-foot distance is possible. Approximately 13,000 tons of grout may be pumped through a single hole. The effect of backfilling on the stability of the mine workings was analyzed using SIUPANEL.3D computer program and further verified using finite element analysis techniques. Stiffness of the backfill mix is most critical for enhancing the stability of mine workings. Mine openings do not have to be completely backfilled to enhance their stability. Backfill height of about 50% of the seam

  15. Evaluation of the effect of sodium silicate addition to mine backfill, Gelfill L Part 1

    Institute of Scientific and Technical Information of China (English)

    M. Kermani; F.P. Hassani; E. Aflaki; M. Benzaazoua; M. Nokken

    2015-01-01

    In this paper, the mechanical properties of sodium silicate-fortified backfill, called Gelfill, were investi-gated by conducting a series of laboratory experiments. Two configurations were tested, i.e. Gelfill and cemented hydraulic fill (CHF). The Gelfill has an alkali activator such as sodium silicate in its materials in addition to primary materials of mine backfill which are tailings, water and binders. Large numbers of samples of Gelfill and CHF with various mixture designs were cast and cured for over 28 d. The me-chanical properties of samples were investigated using uniaxial compression test, and the results were compared with those of reference samples made without sodium silicate. The test results indicated that the addition of an appropriate amount of an alkali activator such as sodium silicate can enhance the mechanical (uniaxial compressive strength) and physical (water retention) properties of backfill. The microstructure analysis conducted by mercury intrusion porosimetry (MIP) revealed that the addition of sodium silicate can modify the pore size distribution and total porosity of Gelfill, which can contribute to the better mechanical properties of Gelfill. It was also shown that the time and rate of drainage in the Gelfill specimens are less than those in CHF specimens made without sodium silicate. Finally, the study showed that the addition of sodium silicate can reduce the required setting time of mine backfill, which can contribute to increase mine production in accordance with the mine safety.

  16. Numerical simulation of wave-induced scour and backfilling processes beneath submarine pipelines

    DEFF Research Database (Denmark)

    Fuhrman, David R.; Baykal, Cüneyt; Sumer, B. Mutlu

    2014-01-01

    A fully-coupled hydrodynamic/morphodynamic numerical model is presented and utilized for the simulation of wave-induced scour and backfilling processes beneath submarine pipelines. The model is based on solutions to Reynolds-averaged Navier–Stokes equations, coupled with k−ω turbulence closure...

  17. Experimental and numerical study of wave-induced backfilling beneath submarine pipelines

    DEFF Research Database (Denmark)

    Bayraktar, Deniz; Ahmad, Joseph; Eltard-Larsen, Bjarke

    2016-01-01

    This paper presents results of complementary experimental and numerical studies involving wave-induced backfilling of current-generated scour holes beneath submarine pipelines. The laboratory experiments are conducted in a wave-plus-current flume, utilizing Laser Doppler Anemometry to measure...

  18. Fluid transport along gutta-percha backfills with and without sealer

    NARCIS (Netherlands)

    Wu, MK; van der Sluis, LWM; Wesselink, PR

    2004-01-01

    Objective. The use of heat may influence the sealing ability of sealer. The aim of this study was to compare the fluid transport along the gutta-percha backfill portion when different sealers were used or no sealer at all. Study design. Four groups consisting of the roots of maxillary and mandibular

  19. Buffer, backfill and closure process report for the safety assessment SR-Site

    Energy Technology Data Exchange (ETDEWEB)

    Sellin, Patrik (ed.)

    2010-11-15

    This report gives an account of how processes in buffer, deposition tunnel backfill and the closure important for the long-term evolution of a KBS-3 repository for spent nuclear fuel, will be documented in the safety assessment SR-Site

  20. Evaluation of the effect of sodium silicate addition to mine backfill, Gelfill − Part 1

    Directory of Open Access Journals (Sweden)

    M. Kermani

    2015-06-01

    Full Text Available In this paper, the mechanical properties of sodium silicate-fortified backfill, called Gelfill, were investigated by conducting a series of laboratory experiments. Two configurations were tested, i.e. Gelfill and cemented hydraulic fill (CHF. The Gelfill has an alkali activator such as sodium silicate in its materials in addition to primary materials of mine backfill which are tailings, water and binders. Large numbers of samples of Gelfill and CHF with various mixture designs were cast and cured for over 28 d. The mechanical properties of samples were investigated using uniaxial compression test, and the results were compared with those of reference samples made without sodium silicate. The test results indicated that the addition of an appropriate amount of an alkali activator such as sodium silicate can enhance the mechanical (uniaxial compressive strength and physical (water retention properties of backfill. The microstructure analysis conducted by mercury intrusion porosimetry (MIP revealed that the addition of sodium silicate can modify the pore size distribution and total porosity of Gelfill, which can contribute to the better mechanical properties of Gelfill. It was also shown that the time and rate of drainage in the Gelfill specimens are less than those in CHF specimens made without sodium silicate. Finally, the study showed that the addition of sodium silicate can reduce the required setting time of mine backfill, which can contribute to increase mine production in accordance with the mine safety.

  1. Efficacy of backfilling and other engineered barriers in a radioactive waste repository in salt

    Energy Technology Data Exchange (ETDEWEB)

    Claiborne, H.C.

    1982-09-01

    In the United States, investigation of potential host geologic formations was expanded in 1975 to include hard rocks. Potential groundwater intrusion is leading to very conservative and expensive waste package designs. Recent studies have concluded that incentives for engineered barriers and 1000-year canisters probably do not exist for reasonable breach scenarios. The assumption that multibarriers will significantly increase the safety margin is also questioned. Use of a bentonite backfill for surrounding a canister of exotic materials was developed in Sweden and is being considered in the US. The expectation that bentonite will remain essentially unchanged for hundreds of years for US repository designs may be unrealistic. In addition, thick bentonite backfills will increase the canister surface temperature and add much more water around the canister. The use of desiccant materials, such as CaO or MgO, for backfilling seems to be a better method of protecting the canister. An argument can also be made for not using backfill material in salt repositories since the 30-cm-thick space will provide for hole closure for many years and will promote heat transfer via natural convection. It is concluded that expensive safety systems are being considered for repository designs that do not necessarily increase the safety margin. It is recommended that the safety systems for waste repositories in different geologic media be addressed individually and that cost-benefit analyses be performed.

  2. Water saturation phase of the buffer and backfill in the KBS-3V concept. Special emphasis given to the influence of the backfill on the wetting of the buffer

    Energy Technology Data Exchange (ETDEWEB)

    Boergesson, Lennart; Faelth, Billy [Clay Technology AB, Lund (Sweden); Hernelind, Jan [5T Engineering AB, Vaesteraas (Sweden)

    2006-08-15

    The wetting and rate of saturation of the buffer and backfill materials in a KBS- V repository from the rock fractures and the rock matrix have been investigated by a large number of different finite element models and calculations. For most models the FE-code ABAQUS has been used but for investigation of the influence of trapped air in the backfill FE-code Code Bright was used. Both codes include completely coupled THM models, which have been used, but for some calculations it has been sufficient to limit the models to only use the hydraulic or thermohydraulic parts of the models. The following analyses have been made: 1. The influence of the backfill properties and wetting conditions on the water saturation phase of the buffer has been investigated with the old FEM-model used in earlier wetting calculations for SR-97. The old calculations have been updated regarding the influence of the backfill. The model is 2-dimensional with axial symmetry around the axis of the deposition hole. These calculations show that there is strong influence of wetting from the backfill if the rock is rather dry (K{sub rock} = 10{sup -13} m/s), while the influence is low if the rock is rather wet (K{sub rock} = 10{sup -12} m/s). At K{sub rock} = 10{sup -13} m/s the time to saturation decreases with a factor 2 in the absence of fractures and with a factor 1.5 with two fractures intersecting the hole when water is supplied from the backfill (30/70) compared to when no water is available. A completely dry rock yields very long time to saturation and of course decisive influence of the water supply from the backfill. If water is freely available at a water pressure of 5 MPa in the backfill it takes 250-500 years to reach full saturation of the buffer. If the water available in the backfill is limited to the initial amount (completely dry rock also around the tunnel and thus no addition of water from the rock in the tunnel) it will take several thousands years to reach some kind of

  3. Paste-like self-flowing transportation backfilling technology based on coal gangue

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-min; ZHAO Bin; ZHANG Chuan-shu; ZHANG Qin-li

    2009-01-01

    A paste-like self-flowing pipeline transportation backfilling technology with coal gangue as aggregate is proposed to remove the potential damage caused by coal gangue piles. As well, the difficult problems of recovering high quality safety coal pillars and deep mining of the Suncun Coal Mine (SCM), Xinwen Coal Group, Shandong are resolved. The physical-chemical properties of coal gangue, optimized proportion of materials, backfilling system and craft in the SCM were studied in the laboratory and then an industrial test was carried out on high quality coal pillars under a town. The results show that finely crushed kaolinized and fresh gangue with granularity less than 5 mm can be used as aggregate with fly ash to replace part of the cement and a compos-ite water reducer as an additive, accounting for 1.0%-1.5% of the total amount of cement and fly ash. The recommended proportion is I(cement):4(fly ash): 15(coal gangue), with a mass fraction of 72%-75%, theological paste-like properties and a strength of more than 0.7 MPa at 7 d. The sequence of adding cement, fly ash, water reducer and then coal gangue ensures that the suspended state of the slurry, reducing the wear and jam of pipelines. The working face is advancing continuously by the alternating craft of building block walls with coal gangue and backfilling mined-out gobs with paste-like slurry. The recovery rate is as high as 90% with a backfilling cost of 36.9 Yuan/t, good utilization of coal gangue and no subsidence on the surface. This technology provides a good theoretical basis and application experience for coal mines, cement backfilling with paste-like slurry.

  4. Colloids in the mortar backfill of a cementitious repository for radioactive waste.

    Science.gov (United States)

    Wieland, E; Spieler, P

    2001-01-01

    Colloids are present in groundwater aquifers and water-permeable engineered barrier systems and may facilitate the migration of radionuclides. A highly permeable mortar is foreseen to be used as backfill for the engineered barrier of the Swiss repository for low- and intermediate-level waste. The backfill is considered to be a chemical environment with some potential for colloid generation and, due to its high porosity, for colloid mobility. Colloid concentration measurements were carried out using an in-situ liquid particle counting system. The in-house developed counting system with three commercially available sensors allowed the detection of single particles and colloids at low concentrations in the size range 50-5000 nm. The counting system was tested using suspensions prepared from certified size standards. The concentrations of colloids with size range 50-1000 nm were measured in cement pore water, which was collected from a column filled with a highly permeable backfill mortar. The chemical composition of the pore water corresponded to a Ca(OH)2-controlled cement system. Colloid concentrations in the backfill pore water were found to be typically lower than approximately 0.1 ppm. The specific (geometric) surface areas of the colloid populations were in the range 240 m2 g(-1) to 770 m2 g(-1). The low colloid inventories observed in this study can be explained by the high ionic strength and Ca concentrations of the cement pore water. These conditions are favourable for colloid-colloid and colloid-backfill interactions and unfavourable for colloid-enhanced nuclide transport.

  5. Treatment Technology on Roof Fall and Landslide of Backfilled Tunnel in Goaf%采空区回填体隧道冒顶塌方处理技术

    Institute of Scientific and Technical Information of China (English)

    谈东亚

    2014-01-01

    Based on the example of treatment on backfilled landslide in goaf encountered in Wusong Tunnel construction in Tongling,according to the characteristics of goaf backfilling roof fall and landslide,from the safety angle,measures are used to deal with the landslide,like temporary reinforcement of the sound section with circumferential vertical steel support,ad-vanced support with cuff shed pipe,grouting reinforcement with cement water glass,reservation core soil excavation,backfill-ing of light weight concrete,arch replacement technology,so as to provide references for similar projects in the future.%以铜陵市五松隧道在施工中遇到的采空区回填体塌方处理为例,针对采空区回填体导致冒顶塌方的特点,从安全顺利的角度,通过临时环向竖向钢支撑加固未塌方段、套管法超前管棚超前预支护、水泥水玻璃注浆加固、预留核心土法开挖支护、回填轻质混凝土、换拱等技术,安全顺利地处理完该塌方,为今后类似工程提供一定的参考。

  6. 土工袋技术在市政沟槽回填中的应用研究%Application of soilbags to urban trench backfill

    Institute of Scientific and Technical Information of China (English)

    刘斯宏; 高军军; 王子健; 王柳江; 胡晓平

    2014-01-01

    市政工程中管线埋入地下采用的基本流程是先开挖沟槽,将开挖的原土作为渣土处理,待管线在沟槽中安放后再用二灰土石填埋沟槽,经夯实后铺设沥青或混凝土路面。为了有效利用沟槽开挖土、减少二灰土石用量,建议采用土工袋技术处理,即将沟槽开挖土装入土工编织袋后回填至沟槽中。阐述了土工袋技术原理,并依托南京市雨污分流工程,对用土工袋回填的沟槽进行了平板载荷试验、落锤式挠度检测和路面振动测试,评价土工袋沟槽的回填效果。结果表明:土工袋在提高沟槽承载力、减少沉降变形、削弱交通振动干扰等方面具有明显效果。土工袋避免弃土外运,减少了扬尘污染,不失为一种绿色、环保、经济的工程新技术。%The basic way to bury pipelines into ground in the municipal projects is:excavating a trench firstly, and throwing away the excavated soils as wastes; backfilling the expensive lime-ash soil into the trench after the pipelines are placed properly; tamping foundation and laying asphalt or concrete pavements. In consideration of recycling the excavated soils and reducing the use of lime-ash soil, soilbag technique is suggested in urban trench backfills so as to cut down the project costs. The mechanism of soilbag technique is briefly elucidated herein; and several field tests such as plate loading test, falling-weight deflection and vibration response measurements are then carried out respectively to evaluate the benefits of a soilbag-trench, with the strong support of the Rain and Sewage Diversion Project in Nanjing. The test results show that soilbag technique performances superbly in improving the bearing capacity of subgrade, decreasing the settlement of roadbed as well as in reducing and isolating the traffic-induced vibrations, compared with the common backfill scheme. It is also proved that backfilling the trench with soilbags is a

  7. Roadway backfill method to prevent geohazards induced by room and pillar mining: a case study in Changxing coal mine, China

    Science.gov (United States)

    Zhou, Nan; Li, Meng; Zhang, Jixiong; Gao, Rui

    2016-11-01

    Coal mines in the western areas of China experience low mining rates and induce many geohazards when using the room and pillar mining method. In this research, we proposed a roadway backfill method during longwall mining to target these problems. We tested the mechanical properties of the backfill materials to determine a reasonable ratio of backfill materials for the driving roadway during longwall mining. We also introduced the roadway layout and the backfill mining technique required for this method. Based on the effects of the abutment stress from a single roadway driving task, we designed the distance between roadways and a driving and filling sequence for multiple-roadway driving. By doing so, we found the movement characteristics of the strata with quadratic stabilization for backfill mining during roadway driving. Based on this research, the driving and filling sequence of the 3101 working face in Changxing coal mine was optimized to avoid the superimposed influence of mining-induced stress. According to the analysis of the surface monitoring data, the accumulated maximum subsidence is 15 mm and the maximum horizontal deformation is 0.8 mm m-1, which indicated that the ground basically had no obvious deformation after the implementation of the roadway backfill method at 3101 working face.

  8. Position-optimization on retained entry and backfilling wall in gob-side entry retaining techniques

    Institute of Scientific and Technical Information of China (English)

    Xiaowei Feng; Nong Zhang

    2015-01-01

    This study investigates the stability problem of gob-side entry retaining (GER) and backfilling wall which located under the key block B. Based on the combined research of elastic–plastic mechanics, structure mechanics and modern theory of mining-induced pressure, the caving characteristic and roof structure over the GER were analyzed, and the vertical force and the torque on retained entry roof were also derived as the position for the retained entry varies. On the basis of the specific geology in Huainan mining area, the results indicate that a relatively more stable position for retained entry neighbors the hinge point of block A and B, and it also located at a scope ranging from this point to the one-third length of block B in horizontal direction. As to appropriate position for backfilling wall, this study recommends partial-road-in backfilling method for GER. Field trial conducted at panel face 12418 of Xieqiao Mine demonstrates that the recommended width for original entry is 3.6 m and the preferred width proportion between original retained entry and original entry is 75%or so whereas the avoidable one is 88%or so. These findings provide qualitative references to the mines which share similar geology as what Huainan mining area characterized.

  9. Modeling coupled blast/structure interaction with Zapotec, benchmark calculations for the Conventional Weapon Effects Backfill (CONWEB) tests.

    Energy Technology Data Exchange (ETDEWEB)

    Bessette, Gregory Carl

    2004-09-01

    Modeling the response of buried reinforced concrete structures subjected to close-in detonations of conventional high explosives poses a challenge for a number of reasons. Foremost, there is the potential for coupled interaction between the blast and structure. Coupling enters the problem whenever the structure deformation affects the stress state in the neighboring soil, which in turn, affects the loading on the structure. Additional challenges for numerical modeling include handling disparate degrees of material deformation encountered in the structure and surrounding soil, modeling the structure details (e.g., modeling the concrete with embedded reinforcement, jointed connections, etc.), providing adequate mesh resolution, and characterizing the soil response under blast loading. There are numerous numerical approaches for modeling this class of problem (e.g., coupled finite element/smooth particle hydrodynamics, arbitrary Lagrange-Eulerian methods, etc.). The focus of this work will be the use of a coupled Euler-Lagrange (CEL) solution approach. In particular, the development and application of a CEL capability within the Zapotec code is described. Zapotec links two production codes, CTH and Pronto3D. CTH, an Eulerian shock physics code, performs the Eulerian portion of the calculation, while Pronto3D, an explicit finite element code, performs the Lagrangian portion. The two codes are run concurrently with the appropriate portions of a problem solved on their respective computational domains. Zapotec handles the coupling between the two domains. The application of the CEL methodology within Zapotec for modeling coupled blast/structure interaction will be investigated by a series of benchmark calculations. These benchmarks rely on data from the Conventional Weapons Effects Backfill (CONWEB) test series. In these tests, a 15.4-lb pipe-encased C-4 charge was detonated in soil at a 5-foot standoff from a buried test structure. The test structure was composed of a

  10. shandong gold grand Mining company Backfilling Performance research%山东黄金盛大矿业公司尾砂性能研究

    Institute of Scientific and Technical Information of China (English)

    高干; 符勇

    2014-01-01

    through chemical and physical properties experiment of the iron ore backfilling, the sizes of backfilling materials are classified and the backfilling materials below 0.037 mm are removed. the results show that the backfilling materials classification is an ideal filling aggregate.%通过铁矿尾砂的物理化学性质实验,将尾砂中的细粒级进行分级,即把-0.037 mm以下的细粒级尾砂分级去除,结果表明分级尾砂是理想的充填骨料。

  11. Analysis on Filling Ratio and Shield Supporting Pressure for Overburden Movement Control in Coal Mining with Compacted Backfilling

    Directory of Open Access Journals (Sweden)

    Yanli Huang

    2016-12-01

    Full Text Available Since the weight of overburden is sustained by both the backfill body and the unmined solid coal in coal mining with compacted backfilling (CMCB panels, the stress and deformation characteristics of the surrounding rocks in coal mining are radically changed. The overburden movement control mechanism by coordinating with backfill body and shield in CMCB was studied systematically in this paper. Based on the analysis of deformational and structural characteristics of surrounding rock in CMCB panels, the methods of theoretical analysis, numerical simulation and engineering test are employed. The results show that the fracture of the main roof is mainly controlled by the filling ratio φ and is non-correlated to the shield supporting pressure p. However, p has a significant control effect on the deflection of roof within the shield canopy length, and adversely affects the filling ratio. With the increase of the filling ratio of the gob, the maximum sagging of the immediate and the main roofs, the peak front and the influence range of the abutment pressures are gradually reduced. Correspondingly, the stable period of internal pressure of backfill body in the gob is shortened. Engineering practice shows that the sagging of the gob roof, the distribution of the abutment pressure, the distribution of the internal pressure in the backfill body, and the ground surface sagging results obtained by the in-situ measurement are approximately corresponding to the theoretical analysis and numerical simulation results.

  12. 对坦墙墙后土体第二破裂面的研究%Research on The Second Failure Surface of Backfill Behind Retaining Wall With Gentle Back Surface

    Institute of Scientific and Technical Information of China (English)

    杨雪强; 范瑛

    2001-01-01

    Based on soil plasticity and limit analysis theory,the second failure surface of backfill behind retaining wall with gentle back surface are studied from two view points of maximum active soil pressure and minimum resistive overturning safety factor,and it is further considered that the minimum resistive overturning safety factor is the best approach to studying the failure mechanism of backfill under complex back surface conditions of retaining structures.%基于土的塑性极限分析理论,从挡土墙最小抗倾覆安全系数和挡土墙背上的最大主动土压力两个角度,分别研究了坦墙后土体中第二破裂面的位置,认为在复杂的挡土结构墙背条件下,用最小抗倾覆安全系数来研究挡土墙后土体的破坏机制较为合理。

  13. BEHAVIOUR OF BACKFILL MATERIALS FOR ELECTRICAL GROUNDING SYSTEMS UNDER HIGH VOLTAGE CONDITIONS

    Directory of Open Access Journals (Sweden)

    S. C. LIM

    2015-06-01

    Full Text Available Backfill materials like Bentonite and cement are effective in lowering grounding resistance of electrodes for a considerable period. During lightning, switching impulses and earth fault occurrences in medium and high voltage networks, the grounding system needs to handle extremely high currents either for a short duration or prolonged period respectively. This paper investigates the behaviour of bentonite, cement and sand under impulse and alternating high voltage (50Hz conditions. Fulguritic-formation was observed in all materials under alternating high voltage. The findings reveal that performance of grounding systems under high voltage conditions may significantly change from the outcomes anticipated at design stage.

  14. Deep repository - Engineered barrier system. Erosion and sealing processes in tunnel backfill materials investigated in laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sanden, Torbjoern; Boergesson, Lennart; Dueck, Ann; Goudarzi, Reza; Loennqvist, Margareta (Clay Technology AB, Lund (Sweden))

    2008-12-15

    SKB in Sweden and Posiva in Finland are developing and plan to implement similar disposal concepts for the final disposal of spent nuclear fuel. Co-operation and joint development work between Posiva and SKB with the overall objective to develop backfill concepts and techniques for sealing and closure of the repository have been going on for several years. The investigation described in this report is intended to acquire more knowledge regarding the behavior of some of the candidate backfilling materials. Blocks made of three different materials (Friedland clay, Asha 230 or a bentonite/ballast 30/70 mixture) as well as different bentonite pellets have been examined. The backfill materials will be exposed to an environment simulating that in a tunnel, with high relative humidity and water inflow from the rock. The processes and properties investigated are: 1. Erosion properties of blocks and pellets (Friedland blocks, MX-80 pellets, Cebogel QSE pellets, Minelco and Friedland granules). 2. Displacements of blocks after emplacement in a deposition drift (Blocks of Friedland, Asha 230 and Mixture 30/70). 3. The ability of these materials to seal a leaking in-situ cast plug cement/rock but also other fractures in the rock (MX-80 pellets). 4. The self healing ability after a piping scenario (Blocks of Friedland, Asha 230 Mixture 30/70 and also MX-80 pellets). 5. Swelling and cracking of the compacted backfill blocks caused by relative humidity. The erosion properties of Friedland blocks were also investigated in Phase 2 of the joint SKBPosiva project 'Backfilling and Closure of the Deep Repository, BACLO, which included laboratory scale experiments. In this phase of the project (3) some completing tests were performed with new blocks produced for different field tests. These blocks had a lower density than intended and this has an influence on the erosion properties measured. The erosion properties of MX-80 pellets were also investigated earlier in the project but

  15. A device for vacuum drying, inert gas backfilling and solder sealing of hermetic implant packages.

    Science.gov (United States)

    Schuettler, Martin; Huegle, Matthias; Ordonez, Juan S; Wilde, Juergen; Stieglitz, Thomas

    2010-01-01

    Modern implanted devices utilize microelectronics that have to be protected from the body fluids in order to maintain their functionality over decades. Moisture protection of implants is addressed by enclosing the electronic circuits into gas-tight packages. In this paper we describe a device that allows custom-built hermetic implant packages to be vacuum-dried (removing residual moisture from inside the package), backfilled with an inert gas at adjustable pressure and hermetically sealed employing a solder seal. A typical operation procedure of the device is presented.

  16. Mechanism of Geogrid Reinforced Soil at Bridge Approach

    Institute of Scientific and Technical Information of China (English)

    FENG Guangle; LUO Rong; CHEN Congxin

    2007-01-01

    Using Geogrid-Reinforced Soil (GRS) we studied the working mechanism and design method of GRS at bridge approach with high backfill by field experiment. In a highway section where the height of backfill is 13.5 meters, geogrids were used at two bridge approaches to address the bumping problems. Some soil pressure cells were used to measure the normal and lateral soil pressure at different locations in the roadbed. The experimental results indicate that geogrids in geogrid-reinforced soil (GRS) could produce an uplift force, the closer the location to the abutment, the larger the uplift force, and the reduction of measured soil pressures compared with theoretical values was the largest at the bottom of roadbed, less at the top than at the bottom, and the least in the mid-height of roadbed than at the bottom. These findings are different from those of the traditional greogrid-reinforced subgrade design method.

  17. Mining pressure monitoring and analysis in fully mechanized backfilling coal mining face-A case study in Zhai Zhen Coal Mine

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiang; ZHANG Ji-xiong; KANG Tao; SUN Qiang; LI Wei-kang

    2015-01-01

    Fully mechanized solid backfill mining (FMSBM) technology adopts dense backfill body to support the roof. Based on the distinguishing characteristics and mine pressure control principle in this technology, the basic principles and methods for mining pressure monitoring were analyzed and established. And the characteristics of overburden strata movement were analyzed by monitoring the support resistance of hydraulic support, the dynamic subsidence of immediate roof, the stress of backfill body, the front abutment pressure, and the mass ratio of cut coal to backfilled materials. On-site strata behavior measurements of 7403W solid backfilling working face in Zhai Zhen Coal Mine show that the backfill body can effectively support the overburden load, obviously control the overburden strata movement, and weaken the strata behaviors distinctly. Specific performances are as follows. The support resistance decreases obviously; the dynamic subsidence of immediate roof keeps consistent to the variation of backfill body stress, and tends to be stable after the face retreating to 120-150 m away from the cut. The peak value of front abutment pressure arises at 5-12 m before the operating face, and mass ratio is greater than the designed value of 1.15, which effectively ensures the control of strata movement. The research results are bases for intensively studying basic theories of solid backfill mining strata behaviors and its control, and provide theoretical guidance for engineering design in FMSBM.

  18. Soil-Structure Interaction for Non-Slender, Large-Diameter Offshore Monopiles

    DEFF Research Database (Denmark)

    Sørensen, Søren Peder Hyldal

    . The monopile foundation concept has been employed as the foundation for the majority of the currently installed offshore wind turbines. Therefore, this PhD thesis concerns the soil-pile interaction for non-slender, large-diameter offshore piles. A combination of numerical and physical modelling has been....... Hence, the application of an overburden pressure is possible. The timescale of the backfill process and the compaction of soil material backfilled around piles in storm conditions have been investigated by means of large-scale physical modelling....

  19. Modelling geochemical and microbial consumption of dissolved oxygen after backfilling a high level radiactive waste repository.

    Science.gov (United States)

    Yang, Changbing; Samper, Javier; Molinero, Jorge; Bonilla, Mercedes

    2007-08-15

    Dissolved oxygen (DO) left in the voids of buffer and backfill materials of a deep geological high level radioactive waste (HLW) repository could cause canister corrosion. Available data from laboratory and in situ experiments indicate that microbes play a substantial role in controlling redox conditions near a HLW repository. This paper presents the application of a coupled hydro-bio-geochemical model to evaluate geochemical and microbial consumption of DO in bentonite porewater after backfilling of a HLW repository designed according to the Swedish reference concept. In addition to geochemical reactions, the model accounts for dissolved organic carbon (DOC) respiration and methane oxidation. Parameters for microbial processes were derived from calibration of the REX in situ experiment carried out at the Aspö underground laboratory. The role of geochemical and microbial processes in consuming DO is evaluated for several scenarios. Numerical results show that both geochemical and microbial processes are relevant for DO consumption. However, the time needed to consume the DO trapped in the bentonite buffer decreases dramatically from several hundreds of years when only geochemical processes are considered to a few weeks when both geochemical reactions and microbially-mediated DOC respiration and methane oxidation are taken into account simultaneously.

  20. Evaluation of Computational Method of High Reynolds Number Slurry Flow for Caverns Backfilling

    Energy Technology Data Exchange (ETDEWEB)

    Bettin, Giorgia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-05-01

    The abandonment of salt caverns used for brining or product storage poses a significant environmental and economic risk. Risk mitigation can in part be address ed by the process of backfilling which can improve the cavern geomechanical stability and reduce the risk o f fluid loss to the environment. This study evaluate s a currently available computational tool , Barracuda, to simulate such process es as slurry flow at high Reynolds number with high particle loading . Using Barracuda software, a parametric sequence of simu lations evaluated slurry flow at Re ynolds number up to 15000 and loading up to 25%. Li mitations come into the long time required to run these simulation s due in particular to the mesh size requirement at the jet nozzle. This study has found that slurry - jet width and centerline velocities are functions of Re ynold s number and volume fractio n The solid phase was found to spread less than the water - phase with a spreading rate smaller than 1 , dependent on the volume fraction. Particle size distribution does seem to have a large influence on the jet flow development. This study constitutes a first step to understand the behavior of highly loaded slurries and their ultimate application to cavern backfilling.

  1. Assessment of (222)Rn emanation from ore body and backfill tailings in low-grade underground uranium mine.

    Science.gov (United States)

    Mishra, Devi Prasad; Sahu, Patitapaban; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2014-02-01

    This paper presents a comparative study of (222)Rn emanation from the ore and backfill tailings in an underground uranium mine located at Jaduguda, India. The effects of surface area, porosity, (226)Ra and moisture contents on (222)Rn emanation rate were examined. The study revealed that the bulk porosity of backfill tailings is more than two orders of magnitude than that of the ore. The geometric mean radon emanation rates from the ore body and backfill tailings were found to be 10.01 × 10(-3) and 1.03 Bq m(-2) s(-1), respectively. Significant positive linear correlations between (222)Rn emanation rate and the (226)Ra content of ore and tailings were observed. For normalised (226)Ra content, the (222)Rn emanation rate from tailings was found to be 283 times higher than the ore due to higher bulk porosity and surface area. The relative radon emanation from the tailings with moisture fraction of 0.14 was found to be 2.4 times higher than the oven-dried tailings. The study suggested that the mill tailings used as a backfill material significantly contributes to radon emanation as compared to the ore body itself and the (226)Ra content and bulk porosity are the dominant factors for radon emanation into the mine atmosphere.

  2. 30 CFR 717.14 - Backfilling and grading of road cuts, mine entry area cuts, and other surface work areas.

    Science.gov (United States)

    2010-07-01

    ... to prevent leaching of toxic pollutants. Barren rock or similar materials excess to the mining... MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS UNDERGROUND MINING GENERAL PERFORMANCE STANDARDS § 717.14 Backfilling and grading of road cuts, mine entry area...

  3. Effect of Waste Brick as Mineral Admixture on the Mechanical Performance of Cemented Paste Backfill

    Science.gov (United States)

    Külekçi, Gökhan; Erçikdi, Bayram; Aliyazicioğlu, Şener

    2016-10-01

    This study presents the replacement and addition of granulated waste brick (WB) to ordinary Portland cement (OPC) in a cemented paste backfill (CPB) of sulphide tailings. The addition and OPC rate is about 15-45% and 7% in weight respectively. Pozzolanic activity tests indicated the fineness of WB samples being the major factor of pozzolanic activity instead of chemical composition. All CPB samples displayed the required strength and durability when WB was used as an additive to OPC. On the other hand, a binder dosage of >7wt % was needed to apply the required 28-day strength of ≥ 0.7 MPa when the OPC was replaced by 15-45 wt% WB samples. The durability of CPB samples is closely inter-related with the calcination temperatures and glass phase content of WB.

  4. Chemical modeling of backfill composed of quartz sand, lime and an Fe-phase

    Energy Technology Data Exchange (ETDEWEB)

    Meike, A.; Glassley, W.E.

    1997-01-01

    The area adjacent to the waste package is an important component of the engineered barrier system in a high level radioactive waste repository. The combination of lime, quartz sand, and a phase containing reduced iron is investigated whether it can achieve reduction of oxygen in the waste emplacement drift (thereby reducin corrosion rates) and increase the pH. The simulations conducted to date have examined the following backfill options: Fe metal only, Fe metal and lime, and iron metal/lime/quartz sand in equal volume ratios. Each option was simulated under two environments: limited and unlimited air exchange with the atmosphere. Results suggest that the most important variable during the process of chemical conditioning is the amount of air exchange that occurs in the emplacement drift. The desired chemical conditioing (both oxidation potential and pH) will be far less effective in an emplacement that experiences an unlimited exchange of air with the atmosphere.

  5. Improved recovery in highwall mining using backfill. ACARP Project C3052

    Energy Technology Data Exchange (ETDEWEB)

    Hume, R.G.; Searle, G.K. [BFP, Richmond, Vic. (Australia)

    1998-07-01

    In Australia, coal mines have generally not adopted filling to increase mining recovery. The aim of this project, entitled 'Improved recovery in highwall mining using backfill', was to examine the feasibility of using fill to improve recovery in highwall mining. Current fill practice was reviewed for metalliferous as well as coal mining, both here in Australia and overseas, for its applicability to highwall mining. Studies were then made at a conceptual level to determine whether fill could be economically used, to determine appropriate sources for fill and to trial key aspects of fill behaviour. A review of filling methods led to conceptual studies being undertaken on seven filling methods and these studies demonstrated that fill could be used to improve recovery. These studies were then further refined. Selected filling materials have been reviewed and laboratory tests have been made on these to assess their suitability. 40 refs., 5 figs., 2 tabs.

  6. Engineered Barrier System - Long-term Stability of Buffer and Backfill. Synthesis and extended abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Apted, Mick; Arthur, Randy [Monitor Scientific LLC, Denver, CO (United States); Savage, Dave [Quintessa Ltd., Nottingham (GB)] (eds.)

    2005-09-15

    SKI is preparing to review the license applications being developed by the Swedish Nuclear Fuel and Waste Management Company (SKB) for an encapsulation plant and a deep repository for the geological disposal of spent nuclear fuel. As part of its preparation, SKI is conducting a series of technical workshops on key aspects of the Engineered Barrier System (EBS) of the repository. This workshop concerns the longterm stability of the buffer and the backfill. Previous workshops have addressed the overall concept for long-term integrity of the EBS, the manufacturing, testing and QA of the EBS and the performance confirmation for the EBS. The goal of this work is to achieve a comprehensive overview of all aspects of SKB's EBS work prior to the handling of forthcoming license applications. The reports from the EBS workshops will be used as one important basis in future review work. The workshops involve the gathering of a sufficient number of independent experts in different subjects of relevance to the particular aspect of EBS. A workshop starts with presentations and discussions among these experts. Following this, SKB presents recent results and responds to questions as part of an informal hearing. Finally, the independent experts and the SKI staff examine the SKB responses from different viewpoints. This report aims to summarise the issues discussed at the buffer and backfill workshop and to extract the essential viewpoints that have been expressed. The report is not a comprehensive record of the discussions and individual statements made by workshop participants should be regarded as opinions rather than proven facts. This reports includes apart from the workshop synthesis, questions to SKB identified prior or during the workshop, and extended abstracts for introductory presentations.

  7. Porewater salinity and the development of swelling pressure in bentonite-based buffer and backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D.A. [Atomic Energy of Canada Limited (Canada)

    2000-06-01

    At the depths proposed for a nuclear fuel waste repository, it is likely that saline groundwater conditions will be encountered in the granitic rocks of Finland and Canada. The potential for saline groundwater to influence of the ability of bentonite-based buffer and backfilling materials to swell and thereby generate swelling pressure has been reviewed. Based on the data collected from existing literature, it would appear that porewater salinities as high as 100 g/l will not compromise the ability of confined, bentonite-based materials to develop a swelling pressure of at least 100 kPa on its confinement, provided the effective clay dry density (ECDD), exceeds approximately 0.9 Mg/m{sup 3}. At densities less than approximately 0.9 Mg/m{sup 3} the swelling pressure of bentonite-based materials may be reduced and become sensitive to salt concentration. The influence of porewater salinity on swelling pressure can be compared on the basis of the ECDD required to develop 100 kPa of swelling pressure. In order to generate 100 kPa of swelling pressure an ECDD of approximately 0.7 Mg/m{sup 3} is required to be present under fresh water or brackish porewater conditions. This density would need to be increased to approximately 0.9 Mg/m{sup 3} where the groundwater conditions were saline. The impact that groundwater salinity will have on density specifications for buffer and backfilling materials are discussed with reference to the nuclear fuel waste disposal concepts of Finland and Canada. (orig.)

  8. Numerical Simulation of Heat Transfer Characteristics of Horizontal Ground Heat Exchanger in Frozen Soil Layer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A simplified numerical model of heat transfer characteristics of horizontal ground heat exchanger (GHE) in the frozen soil layer is presented and the steady-state distribution of temperature field is simulated. Numerical results show that the frozen depth mainly depends on the soil's moisture content and ambient temperature. The heat transfer loss of horizontal GHE tends to grow with the increase of the soil's moisture content and the decrease of ambient temperature. Backfilled materials with optimal thermal conductivity can reduce the thermal loss effectively in the frozen soil. The applicability of the Chinese national standard "Technical Code for Ground Source Heat Pump (GB 50366-2005)" is verified. For a ground source heat pump project, the feasible layout of horizontal GHE should be determined based on the integration of the soil's structure, backfilled materials,weather data, and economic analysis.

  9. Soil-Structure Interaction for Non-Slender, Large-Diameter Offshore Monopiles

    DEFF Research Database (Denmark)

    Sørensen, Søren Peder Hyldal

    conducted. The initial part of p-y curves for non-slender piles has been investigated by means of numerical modelling. The general behaviour of eccentrically loaded non-slender piles has been investigated by physical modelling. These tests have been conducted in the pressure tank at Aalborg University....... Hence, the application of an overburden pressure is possible. The timescale of the backfill process and the compaction of soil material backfilled around piles in storm conditions have been investigated by means of large-scale physical modelling....

  10. The solubility of nickel and its migration through the cementitious backfill of a geological disposal facility for nuclear waste.

    Science.gov (United States)

    Felipe-Sotelo, M; Hinchliff, J; Field, L P; Milodowski, A E; Holt, J D; Taylor, S E; Read, D

    2016-08-15

    This work describes the solubility of nickel under the alkaline conditions anticipated in the near field of a cementitious repository for intermediate level nuclear waste. The measured solubility of Ni in 95%-saturated Ca(OH)2 solution is similar to values obtained in water equilibrated with a bespoke cementitious backfill material, on the order of 5×10(-7)M. Solubility in 0.02M NaOH is one order of magnitude lower. For all solutions, the solubility limiting phase is Ni(OH)2; powder X-ray diffraction and scanning transmission electron microscopy indicate that differences in crystallinity are the likely cause of the lower solubility observed in NaOH. The presence of cellulose degradation products causes an increase in the solubility of Ni by approximately one order of magnitude. The organic compounds significantly increase the rate of Ni transport under advective conditions and show measurable diffusive transport through intact monoliths of the cementitious backfill material.

  11. Experimental studies on the inventory of cement-derived colloids in the pore water of a cementitious backfill material

    Energy Technology Data Exchange (ETDEWEB)

    Wieland, E

    2001-06-01

    The potential role of near-field colloids for the colloid-facilitated migration of radionuclides has stimulated investigations concerning the generation and presence of colloids in the near-field of a repository for low- and intermediate level waste (L/ILW). The highly gas permeable mortar (Nagra designation: mortar M1) is currently favoured as backfill material for the engineered barrier of the planned Swiss L/ILW repository. The cementitious backfill is considered to be a chemical environment with some potential for colloid generation. In a series of batch-style laboratory experiments the physico-chemical processes controlling the inventory of colloids in cement pore water of the backfill were assessed for chemical conditions prevailing in the initial stage of the cement degradation. In these experiments, backfill mortar M1 or quartz, respectively, which may be used as aggregate material for the backfill, were immersed in artificial cement pore water (a NaOH/KOH rich cement fluid). Colloid concentrations in the cement pore water were recorded as a function of time for different experimental settings. The results indicate that a colloid-colloid interaction process (coagulation) controlled the colloid inventory. The mass concentration of dispersed colloids was found to be typically lower than 0.02 ppm in undisturbed batch systems. An upper-bound value was estimated to be 0.1 ppm taking into account uncertainties on the measurements. To assess the potential for colloid generation in a dynamic system, colloid concentrations were determined in the pore water of a column filled with backfill mortar. The chemical conditions established in the mortar column corresponded to conditions observed in the second stage of the cement degradation (a Ca(OH){sub 2{sup -}} controlled cement system). In this dynamic system, the upper-bound value for the colloid mass concentration was estimated to be 0.1 ppm. Implications for radionuclide mobility were deduced taking into account the

  12. Behavior of granular rubber waste tire reinforced soil for application in geosynthetic reinforced soil wall

    Directory of Open Access Journals (Sweden)

    G. G. D. RAMIREZ

    Full Text Available AbstractLarge quantities of waste tires are released to the environment in an undesirable way. The potential use of this waste material in geotechnical applications can contribute to reducing the tire disposal problem and to improve strength and deformation characteristics of soils. This paper presents a laboratory study on the effect of granular rubber waste tire on the physical properties of a clayey soil. Compaction tests using standard effort and consolidated-drained triaxial tests were run on soil and mixtures. The results conveyed an improvement in the cohesion and the angle of internal friction the clayey soil-granular rubber mixture, depending on the level of confining stress. These mixtures can be used like backfill material in soil retaining walls replacing the clayey soil due to its better strength and shear behavior and low unit weight. A numerical simulation was conducted for geosynthetic reinforced soil wall using the clayey soil and mixture like backfill material to analyzing the influence in this structure.

  13. Coupled effect of cement hydration and temperature on hydraulic behavior of cemented tailings backfill

    Institute of Scientific and Technical Information of China (English)

    WU Di; CAI Si-jing

    2015-01-01

    Cemented tailings backfill (CTB) is made by mixing cement, tailings and water together, thus cement hydration and water seepage flow are the two crucial factors affecting the quality of CTB. Cement hydration process can release significant amount of heat to raise the temperature of CTB and in turn increase the rate of cement hydration. Meanwhile, the progress of cement hydration consumes water and produces hydration products to change the pore structures within CTB, which further influences the hydraulic behavior of CTB. In order to understand the hydraulic behavior of CTB, a numerical model was developed by coupling the hydraulic, thermal and hydration equations. This model was then implemented into COMSOL Multiphysics to simulate the evolutions of temperature and water seepage flow within CTB versus curing time. The predicted outcomes were compared with correspondent experimental results, proving the validity and availability of this model. By taking advantage of the validated model, effects of various initial CTB and curing temperatures, cement content, and CTB's geometric shapes on the hydraulic behavior of CTB were demonstrated numerically. The presented conclusions can contribute to preparing more environmentally friendly CTB structures.

  14. THM modelling of buffer, backfill and other system components. Critical processes and scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias; Kristensson, Ola; Boergesson, Lennart; Dueck, Ann (Clay Technology AB, Lund (Sweden)); Hernelind, Jan (5T-Engineering AB, Vaesteraas (Sweden))

    2010-03-15

    A number of critical thermo-hydro-mechanical processes and scenarios for the buffer, tunnel backfill and other filling components in the repository have been identified. These processes and scenarios representing different aspects of the repository evolution have been pinpointed and modelled. In total, 22 cases have been modelled. Most cases have been analysed with finite element (FE) calculations, using primarily the two codes Abaqus and Code-Bright. For some cases analytical methods have been used either to supplement the FE calculations or due to that the scenario has a character that makes it unsuitable or very difficult to use the FE method. Material models and element models and choice of parameters as well as presumptions have been stated for all modelling cases. In addition, the results have been analysed and conclusions drawn for each case. The uncertainties have also been analysed. Besides the information given for all cases studied, the codes and material models have been described in a separate so called data report

  15. Buffer and backfill process report for the safety assessment SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Sellin, Patrik (comp.)

    2006-09-15

    This document compiles information on processes in the buffer and deposition tunnel backfill relevant for long-term safety of a KBS-repository. It supports the safety assessment SR-Can, which is a preparatory step for a safety assessment that will support the licence application for a final repository in Sweden. The purpose of the process reports is to document the scientific knowledge of the processes to a level required for an adequate treatment of the processes in the safety assessment. The documentation is not exhaustive from a scientific point of view, since such a treatment is neither necessary for the purposes of the safety assessment nor possible within the scope of an assessment. However, it must be sufficiently detailed to motivate, by arguments founded on scientific understanding, the treatment of each process in the safety assessment. The purpose is further to determine how to handle each process in the safety assessment at an appropriate degree of detail, and to demonstrate how uncertainties are taken care of, given the suggested handling.

  16. Investigation on hydraulic properties of compacted GMZ bentonite used as buffer/backfill material

    Directory of Open Access Journals (Sweden)

    Ye W. M.

    2016-01-01

    Full Text Available During the past decades, GMZ bentonite has been widely investigated for its use as buffer/backfill materials in China. Based on a comprehensive review of the former studies, achievements on experimental and theoretic works on the hydraulic aspects of compacted GMZ bentonite with consideration of temperature effects are presented in this paper. Water retention property of compacted GMZ bentonite depends on constraint conditions. Temperature effects on water-retention depend on constraint conditions and suction. The hysteresis behaviour is not obvious. Based on the test results, a revised water retention model was developed for considering the temperature effect. The saturated hydraulic conductivity of the densely compacted GMZ bentonite increases as dry density and temperature increases. A revised model, which considers temperature influence on water viscosity and the effective flow cross-sectional area of porous channels, for prediction of saturated hydraulic conductivity have been developed and verified. The unsaturated hydraulic conductivity of confined densely compacted GMZ bentonite samples decreases first and then increases with suction decrease from an initial value of 80 MPa to zero. With consideration of temperature effects and microstructure changes, a revised model for prediction of unsaturated hydraulic conductivity of compacted GMZ01 bentonite was proposed.

  17. A Numerical Model for Natural Backfill of Pipeline Trenches Subjected to Unidirectional/Oscillatory Flows

    Institute of Scientific and Technical Information of China (English)

    LIANG Dong-fang; CHENG Liang; Kervin YEOW

    2005-01-01

    A numerical model for the self-burial of a pipeline trench is developed. Morphological evolutions of a pipeline trench under steady-current or oscillatory-flow conditions are simulated with/without a pipeline inside the trench. The oscillatory flow in this study represents the action of waves. The two-dimensional Reynolds-averaged continuity and Navier-Stokes equations with the standard k-ε turbulence closure, as well as the sediment transport equations, are solved with the finite difference method in a curvilinear coordinate system. Both bed and suspended loads of sediment transport are included in the morphological model. Because of the lack of experimental data on the backfilling of pipeline trenches, the numerical model is firetly verified against three closely-relevant experiments available in literature. A detailed measurement of the channel migration phenomenon under steady currents is employed for the assessment of the integral performance of the model. The two experimental results from U-tube tests are used to validate the model's ability in predicting oscillatory flows. Different time-marching schemes are employed for the morphological computation under unidirectional and oscillatory conditions. It is found that vortex motions within the trench play an important role in the trench development.

  18. SR-Site Data report. THM modelling of buffer, backfill and other system components

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias; Boergesson, Lennart; Kristensson, Ola (Clay Technology AB, Lund (Sweden))

    2010-03-15

    This report is a supplement to the SR-Site data report. Based on the issues raised in the Process reports concerning THM processes in buffer, backfill and other system components, 22 modelling tasks have been identified, representing different aspects of the repository evolution. The purpose of this data report is to provide parameter values for the materials included in these tasks. Two codes, Code{_}Bright and Abaqus, have been employed for the tasks. The data qualification has focused on the bentonite material for buffer, backfill and the seals for tunnel plugs and bore-holes. All these system components have been treated as if they were based on MX-80 bentonite. The sources of information and documentation of the data qualification for the parameters for MX-80 have been listed. A substantial part of the refinement, especially concerning parameters used for Code{_}Bright, is presented in the report. The data qualification has been performed through a motivated and transparent chain; from measurements, via evaluations, to parameter determinations. The measured data was selected to be as recent, traceable and independent as possible. The data sets from this process are thus regarded to be qualified. The conditions for which the data is supplied, the conceptual uncertainties, the spatial and temporal variability and correlations are briefly presented and discussed. A more detailed discussion concerning the data uncertainty due to precision, bias and representativity is presented for measurements of swelling pressure, hydraulic conductivity, shear strength, retention properties and thermal conductivity. The results from the data qualification are presented as a detailed evaluation of measured data. In order to strengthen the relevance of the parameter values and to confirm previously used relations, either newer or independent measurements have been taken into account in the parameter value evaluation. Previously used relations for swelling pressure, hydraulic

  19. Diffusion coefficient test of {sup 237}Np in bentonite backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Cui Anxi; Fan Zhiwen; Zhang Jinsheng; Gu Cunli [China Inst. for Radiation Protection, Shanxi (China); Mukai, M.; Maeda, T.; Matsumoto, J.; Tanaka, T.; Ogawa, H. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-03-01

    This paper describes the work on diffusion coefficient test of Np in bentonite backfill materials. Due to its very low permeability, diffusion is the dominant migration mechanics in bentonite. The bentonite comes from Inner Mongolia of China. {sup 237}Np was used as tracer. The special apparatus for diffusion test was setup, the diffusion coefficient of Np in pure bentonite and sand-bentonite mixture were tested. The tracer was introduced between two bentonite columns. After a specific contacting period, the bentonite columns were taken out and cut to very thin slices. The radioactivity in bentonite slices was analyzed to give the nuclide concentration versus distance curves. The diffusion coefficient could be estimated. The diffusion coefficient of pure bentonite at different density was tested. When the density of pure bentonite samples varied from 1.1, 1.3, 1.5 to 1.7 g/ml, their diffusion coefficient were 1.36 x 10{sup -13} m{sup 2}/s 1.16 x 10{sup -13}m{sup 2}/s, 1.07 x 10{sup -13} m{sup 2}/s and 8.26 x 10{sup -14} m{sup 2}/s respectively. The diffusion coefficient of Np in sand-bentonite mixture sample was 4.13 x 10{sup -13} m{sup 2}/s. To estimate the distribution coefficient (K{sub d}) value of Np in mixture sample by diffusion method, the diffusion coefficient of Br was measured./ The concluded K{sub d} value was 77ml/g for the sand-bentonite mixture. The K{sub d} value obtained by batch test methods was 30ml/g. The reason is related with the error of Br diffusion coefficient and solid-liquid ratio. (author)

  20. Characterization of a backfill candidate material, IBECO-RWC-BF Baclo Project - Phase 3 Laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Johannesson, Lars-Erik; Sanden, Torbjoern; Dueck, Ann; Ohlsson, Lars (Clay Technology AB, Lund (Sweden))

    2010-01-15

    A backfill candidate material, IBECO-RWC-BF, which origin from Milos, Greece, has been investigated. The material was delivered both as granules and as pellets. The investigation described in this report aimed to characterize the material and evaluate if it can be used in a future repository. The following investigations have been done and are presented in this report: 1. Standard laboratory tests. Water content, liquid limit and swelling potential are examples on standard tests that have been performed. 2. Block manufacturing. The block compaction properties of the material have been determined. A first test was performed in laboratory but also tests in large scale have been performed. After finishing the test phase, 60 tons of blocks were manufactured at Hoeganaes Bjuf AB. The blocks will be used in large scale laboratory tests at Aespoe HRL. 3. Mechanical parameters. The compressibility of the material was investigated with oedometer tests (four tests) where the load was applied in steps after saturation. The evaluated oedometer modulus varied between 34.50 MPa. Tests were made to evaluate the elastic parameters of the material (E, nu). Altogether three tests were made on specimens with dry densities of about 1,710 kg/m3. The evaluated E-modulus and Poisson's ratio varied between 231-263 MPa and 0.16-0.19 respectively. The strength of the material, both the compressive strength and the tensile strength were measured on specimens compacted to different dry densities. The test results yielded a relation between density and the two types of strength. Furthermore, tests have been made in order to determine the compressibility of the unsaturated filling of pellets. Two tests were made where the pellets were loosely filled in a Proctor cylinder and then compressed at a constant rate of strain during continuously measurement of the applied load. 4. Swelling pressure and hydraulic conductivity. There is, as expected, a very clear influence of the dry density on the

  1. Characterization of a backfill candidate material, IBECO-RWC-BF Baclo Project - Phase 3 Laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Johannesson, Lars-Erik; Sanden, Torbjoern; Dueck, Ann; Ohlsson, Lars (Clay Technology AB, Lund (Sweden))

    2010-01-15

    A backfill candidate material, IBECO-RWC-BF, which origin from Milos, Greece, has been investigated. The material was delivered both as granules and as pellets. The investigation described in this report aimed to characterize the material and evaluate if it can be used in a future repository. The following investigations have been done and are presented in this report: 1. Standard laboratory tests. Water content, liquid limit and swelling potential are examples on standard tests that have been performed. 2. Block manufacturing. The block compaction properties of the material have been determined. A first test was performed in laboratory but also tests in large scale have been performed. After finishing the test phase, 60 tons of blocks were manufactured at Hoeganaes Bjuf AB. The blocks will be used in large scale laboratory tests at Aespoe HRL. 3. Mechanical parameters. The compressibility of the material was investigated with oedometer tests (four tests) where the load was applied in steps after saturation. The evaluated oedometer modulus varied between 34.50 MPa. Tests were made to evaluate the elastic parameters of the material (E, nu). Altogether three tests were made on specimens with dry densities of about 1,710 kg/m3. The evaluated E-modulus and Poisson's ratio varied between 231-263 MPa and 0.16-0.19 respectively. The strength of the material, both the compressive strength and the tensile strength were measured on specimens compacted to different dry densities. The test results yielded a relation between density and the two types of strength. Furthermore, tests have been made in order to determine the compressibility of the unsaturated filling of pellets. Two tests were made where the pellets were loosely filled in a Proctor cylinder and then compressed at a constant rate of strain during continuously measurement of the applied load. 4. Swelling pressure and hydraulic conductivity. There is, as expected, a very clear influence of the dry density on the

  2. Deep repository - engineered barrier systems. Half scale tests to examine water uptake by bentonite pellets in a block-pellet backfill system

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David (Atomic Energy of Canada Limited (AECL) (Canada)); Lundin, Cecilia (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Oertendahl, Ellinor (NCC (Sweden)); Hedin, Mikael (Aangpannefoereningen, Stockholm (Sweden)); Ramqvist, Gunnar (Eltekno AB (Sweden))

    2008-12-15

    In order to examine the behaviour of water entering a section of tunnel that had recently been backfilled using a combination of bentonite pellets and compacted, smectitic clay blocks, a series of large-scale tests have been completed. These tests, done at a scale of approximately 0.5 that of an emplacement tunnel were completed in a mock-up constructed in the Buffer Laboratory at SKB's Aespoe Hard Rock Laboratory. A total of 12 tests, undertaken under well controlled conditions were completed, examining the effects of inflow rate, inflow location and time on assemblies of blocks and pellets. Water was supplied to the assembly at rates ranging from 0.1 to 2.5 l/min and the time for water exit, the exit location, potential for erosion of backfill, the rate of water uptake and resistance of the assembly to water influx were all monitored for periods of 3 to 7 days. The testing time was selected to simulate a reasonable duration for unanticipated backfilling interruption. Longer durations were not necessary and risked both the stability of the system and the loss of the early stage conditions through progression of swelling and homogenization. Testing determined that initial water movement through backfill is largely controlled by the pellets. Water influx of up to 30 l/h at a single location was diverted by the pellets forming essentially horizontal flow channels (pipes) along the chamber wall - pellet interface. These piping features directed the majority of the incoming water around the backfill and towards the unconfined downstream face of the assembly. The time required for the water to exit the assembly was dependant on a combination of inflow rate and distance that it needed to travel. Water typically exited the face of the backfill at well-defined location(s) and once established, these features remained for the duration of the test. The exiting water typically carried only limited eroded material but could cause some disruption of the downstream face of

  3. Fat metaplasia and backfill are key intermediaries in the development of sacroiliac joint ankylosis in patients with ankylosing spondylitis

    DEFF Research Database (Denmark)

    Maksymowych, Walter P; Wichuk, Stephanie; Chiowchanwisawakit, Praveena

    2014-01-01

    bone in the sacroiliac (SI) joints and may reflect resolution of inflammation and tissue repair at sites of erosions. The purpose of this study was to test our hypothesis that SI joint ankylosis develops following repair of erosions and that tissue characterized by fat metaplasia is a key intermediary...... step in this pathway. METHODS: We used the Spondyloarthritis Research Consortium of Canada (SPARCC) SI structural lesion score (SSS) method to assess fat metaplasia, erosions, backfill, and ankylosis on MRIs of the SI joints in 147 patients with AS monitored for 2 years. Univariate and multivariate...

  4. Use of engineered soils and other site modifications for low-level radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    The U.S. Nuclear Regulatory Commission requires that low-level radioactive waste (LLW) disposal facilities be designed to minimize contact between waste and infiltrating water through the use of site design features. The purpose of this investigation is to identify engineered barriers and evaluate their ability to enhance the long-term performance of an LLW disposal facility. Previously used barriers such as concrete overpacks, vaults, backfill, and engineered soil covers, are evaluated as well as state-of-the-art barriers, including an engineered sorptive soil layer underlying a facility and an advanced design soil cover incorporating a double-capillary layer. The purpose of this investigation is also to provide information in incorporating or excluding specific engineered barriers as part of new disposal facility designs. Evaluations are performed using performance assessment modeling techniques. A generic reference disposal facility design is used as a baseline for comparing the improvements in long-term performance offered by designs incorporating engineered barriers in generic and humid environments. These evaluations simulate water infiltration through the facility, waste leaching, radionuclide transport through the facility, and decay and ingrowth. They also calculate a maximum (peak annual) dose for each disposal system design. A relative dose reduction factor is calculated for each design evaluated. The results of this investigation are presented for concrete overpacks, concrete vaults, sorptive backfill, sorptive engineered soil underlying the facility, and sloped engineered soil covers using a single-capillary barrier and a double-capillary barrier. Designs using combinations of barriers are also evaluated. These designs include a vault plus overpacks, sorptive backfill plus overpacks, and overpack with vault plus sorptive backfill, underlying sorptive soil, and engineered soil cover.

  5. Couple mechanics hydraulics and sorption properties of mixtures to evaluate buffer/backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Yi-Lin, Jan [Ching Yun Univ., Dept. of Civil Engineering, Taiwan (China); Shih-Chin, Tsaia [Fooyin Univ., Dept. of Industrial Safety and Hygiene, Taiwan (China); Yi-Lin, Jan; Chun-Nan, Hsu [National Tsing Hua Univ., Dept. of Nuclear Science, Taiwan (China)

    2005-07-01

    The technique of multi-barrier disposal systems of radwaste has been studying among the world. The buffer materials that retard the migration of nuclides and make the canisters stable play a very important role. To couple engineering and sorption properties to evaluate the buffer/backfill materials, synthetic groundwater (GW) and seawater(SW) were used as the liquid phases to simulate possible conditions for a deep geological disposal in an island. The R{sub d} value of Cs, I and Se (10{sup -4} M ) with respect to various composite ratios of bentonite/ laterite/ quartz sand mixtures were measured using batch sorption tests in GW and SW. De-ionic water (DIW) was used as the liquid phase for Atterberg limit tests, triaxial shear test s and hydraulic conductivity tests to acquire the engineering properties of those mixtures mention above. The Atterberg limit tests results showed that 7 samples are concluded inorganic clays of high plasticity and one is inorganic clays of medium plasticity. The samples with 30% quartz sand content indicate the higher shear strength than those with 50% quartz sand content and very low hydraulic conductivity for all samples are in the same order about 1{sup -10} m/s. The sorption of Cs on mixtures reveals that distribution coefficients (R{sub d}s) is higher in GW than those in SW. The Rd s of Cs are inverse proportion to plastic index (PI) in GW and SW as well as the R{sub d}s of Se. The sorption of Se on mixtures is affected significantly by composition of solid phase. However, the major affection for sorption of Se is solid phase and that of Cs is liquid phase. Very low sorption of I on all mixtures in GW and SW. Under these experimental conditions, these results reveal that more effective buffer material composition of 30% quartz sand content which PI are 40 to 60. Laterite is more effective sorbent for Cs and Se than Bentonite. (authors)

  6. Research and application of schemes for constructing concrete pillars in large section finishing cut in backfill coal mining

    Institute of Scientific and Technical Information of China (English)

    Sun Qiang; Zhang Jixiong; Ju Feng; Li Linyue; Zhao Xu

    2015-01-01

    Based on the technology of controlling surrounding rock deformation by constructing concrete pillars in large section finishing cut in backfill coal mining, the characteristics of vertical stress on concrete pillars and main factors influencing pillar stability are analyzed. By building a Winkler elastic foundation mechanical model for the support system constituted of coal pillar, backfill body and concrete pillars, mechanical calculation on stability of concrete pillar is carried out to evaluate the pillar stability and safety. Seven numeral models in three schemes with different pillar sizes, inter-row distances and com-pression ratios at the stopes were analyzed through numerical simulation according to width reduction principle. The practice of finishing cut at III644 workface at Yangzhuang coal mine shows that:when the actual compression ratio is 86.5%, construction size inside the finishing cut is 2000 mm ? 2000 mm and the interval between concrete pillars is 2000 mm ? 2000 mm, the pillars can be stable with the maxi-mum movement of two sides of each pillar being only 83 mm and 54 mm, which achieves the expected effect.

  7. Initial field testing definition of subsurface sealing and backfilling tests in unsaturated tuff; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.A. [Sandia National Labs., Albuquerque, NM (United States); Case, J.B.; Tyburski, J.R. [I. T. Corp., Albuquerque, NM (United States)

    1993-05-01

    This report contains an initial definition of the field tests proposed for the Yucca Mountain Project repository sealing program. The tests are intended to resolve various performance and emplacement concerns. Examples of concerns to be addressed include achieving selected hydrologic and structural requirements for seals, removing portions of the shaft liner, excavating keyways, emplacing cementitious and earthen seals, reducing the impact of fines on the hydraulic conductivity of fractures, efficient grouting of fracture zones, sealing of exploratory boreholes, and controlling the flow of water by using engineered designs. Ten discrete tests are proposed to address these and other concerns. These tests are divided into two groups: Seal component tests and performance confirmation tests. The seal component tests are thorough small-scale in situ tests, the intermediate-scale borehole seal tests, the fracture grouting tests, the surface backfill tests, and the grouted rock mass tests. The seal system tests are the seepage control tests, the backfill tests, the bulkhead test in the Calico Hills unit, the large-scale shaft seal and shaft fill tests, and the remote borehole sealing tests. The tests are proposed to be performed in six discrete areas, including welded and non-welded environments, primarily located outside the potential repository area. The final selection of sealing tests will depend on the nature of the geologic and hydrologic conditions encountered during the development of the Exploratory Studies Facility and detailed numerical analyses. Tests are likely to be performed both before and after License Application.

  8. Sheetflow Effects and Canal Backfilling on Sediment Source and Transport in Everglades Freshwater Marshes: Analysis of Molecular Organic Biomarkers

    Science.gov (United States)

    Regier, P.; He, D.; Saunders, C.; Coronado-Molina, C.; Jara, B.; Jaffe, R.

    2014-12-01

    Historic freshwater sheetflow in the Florida Everglades distributed sediment to form a ridge-and-slough landscape. However, drainage along with reduction and obstruction of flow has resulted in degradation of this ridged topography. The DECOMP Physical Model is a landscape-scale project aiming to reestablish natural sheetflow to the central and southern Everglades by redesigning barriers to flow. To validate proof of concept that increased flow will rebuild ridge-slough microtopography, biomarker proxies were established for ridge and slough organic matter sources. In addition, partial and complete canal backfill options were assessed via sediment trap accumulation in each backfill treatment area. Flocculent matter (floc) and sediment samples were collected, solvent extracted, chromatographically separated, and analyzed on a GC/MS using internal standard for quantification. Four molecular organic biomarkers were evaluated: the aquatic proxy (Paq), highly-branched isoprenoids (C20 HBI), kaurenes and botyrococcenes. Paq, an aquatic proxy of mid to long-chain n-alkanes, was shown to clearly differentiate between ridge-derived and slough-derived organic matter with Paq values increasing along ridge-to-slough transects. Kaurenes indicated presence of ridge-derived organic matter while C20 HBI and botyrococcenes were indicative of periphyton-derived organic matter which is commonly more abundant in sloughs. Biomarker distributions during both low (present day) and high (managed) water flow through the DECOMP experimental parcel were determined and discussed comparatively.

  9. Laboratory Study on the Use of Tire Shreds and Rubber-Sand in Backfilled and Reinforced Soil Applications

    OpenAIRE

    Bernal, Andres; Lovell, C. W.; Salgado, Rodrigo

    1996-01-01

    Millions of scrap tires are discarded annually in the United States, the bulk of which are currently landfilled or stockpiled. This consumes valuable landfill space, or, if improperly disposed, creates a fire hazard and provides a prolific breeding ground for rats and mosquitoes. The use of tire shreds as lightweight fill material can sharply reduce the tire disposal problem. The present study, based on laboratory testing and numerical modeling examines the feasibility of incorporating tire s...

  10. Direct methods of soil-structure interaction analysis for earthquake loadings(II)

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Chung Bang; Lee, S. R.; Kim, J. M.; Park, K. L.; Oh, S. B.; Choi, J. S.; Kim, Y. S. [Korea Advanced Institute of Science Technology, Daejeon (Korea, Republic of)

    1994-07-15

    In this study, methods for 3-D soil-structure interaction analysis have been studied. They are 3-D axisymmetric analysis method, 3-D axisymmetric finite element method incorporating infinite elements, and 3-D boundary element methods. The computer code, named as 'KIESSI - PF', has been developed which is based on the 3-D axisymmetric finite element method coupled with infinite element method. It is able to simulate forced vibration test results of a soil-structure interaction system. The Hualien FVT post-correlation analysis before backfill and the blind prediction analysis after backfill have been carried out using the developed computer code 'KIESSI - PF'.

  11. Characterisation of bentonites from Kutch, India and Milos, Greece - some candidate tunnel back-fill materials?

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Siv; Karnland, Ola (Clay Technology AB, Lund (Sweden))

    2009-12-15

    During the past decades comprehensive investigations have been made on bentonite clays in order to find optimal components of the multi-barrier system of repositories for radioactive waste. The present study gives a mineralogical characterisation of some selected bentonites, in order to supply some of the necessary background data on the bentonites for evaluating their potential as tunnel back-fill materials. Two bentonites from the island of Milos, Greece (Milos BF 04 and BF 08), and two bentonites from Kutch, India (Kutch BF 04 and BF 08) were analysed for their grain size distribution, cation exchange properties and chemical composition. The mineralogical composition was determined by X-ray diffraction analysis and evaluated quantitatively by use of the Siroquant software. Both the bulk bentonite and the <1mum fraction were analyzed when relevant. Prior to the chemical analyses the <1 mum fractions were converted to homo-ionic clays and purified by dialysis. The chemical data were used for calculating the structural formula of the smectites. Milos BF 04 contains ca. 10% particles >63 mum. The bentonite is distinguished by a high content of dolomite and calcite, which make up almost 25% of the bulk sample. The major accessory minerals are K-feldspars and plagioclase, whereas the content of sulphur-bearing minerals is very low (0.06% total S). Smectite makes up around 60% of the bulk sample, which has a CEC value of 73 meq/100 g. The pool of interlayer cations has a composition Mg>Ca>>Na>>K. The X-ray diffraction characteristics and the high potassium content (1.03% K{sub 2}O) of the <1 mum fraction suggest that the smectite is interstratified with ca. 10% illitic layers. Based on the charge distribution the smectite should be classified as montmorillonite and according to the structural formula, Mg predominates over Fe in the octahedral sheet. However, remnants of Mg-carbonates, if present, may be a source of error in the formula calculation. Milos BF 08 has a

  12. Role of Soil Hysteresis in Impedance Testing as Applied to Buried Arches

    Science.gov (United States)

    1990-02-01

    information . I Add the individual listed to your distribution list. [] Delete the cited organization/individual. El Change of address. NAME: ORGANIZATION...arch structure shows that the backfill soil hysteretic behavoir is a dominant factor in explaining the absence of resonance in arch tests. ~ n0...TECHNICAL INFORMATION CENTER ATTN: ASMS 2CYS ATTN: DTIC/FDAB ATTN: MYE STRATEGIC AND THEATER NUCLEAR FORCES WEAPONS LABORATORY ATTN: DR E SEVIN ATTN

  13. Energy storage and heat transfer characteristics of ground heat exchanger with phase change backfill materials%相变材料回填地埋管换热器蓄能传热特性

    Institute of Scientific and Technical Information of China (English)

    杨卫波; 孙露露; 吴晅

    2014-01-01

    points for the application of GSHP. In this paper, a new type of GHE with phase change backfill materials was presented to change its thermal response characteristics and heat transfer performance. Theoretically, the thermal interference radius of soil can be reduced by the phase change of phase change materials (PCM), and the energy storage performance of GHE can be improved due to the release of phase change latent heat. In order to further investigate the influences of solid-liquid phase change of phase change backfill materials on energy storage and heat transfer performance of GHE, a quasi-three dimensional heat transfer model with phase change was developed for the vertical U-bend GHE, which couples the one-dimensional fluid heat transfer in vertical direction with the two-dimensional soil transient heat transfer in level. The model was discreted by the control volume method and solved by the apparent heat capacity method. Based on the numerical solution of the model, the influences of solid-liquid phase change of PCM on energy storage performance of GHE and thermal response characteristics of soil temperature around GHE were analyzed for winter and summer mode respectively. The effects of phase change temperature and phase change latent heat of PCM on the thermal diffusivity and energy storage characteristics of GHE were discussed. The results indicate that under same conditions, the soil temperature variations trend is slow down and the thermal interference region is reduced due to the heat extraction and release during the phase change of PCM. The heat exchange performance of GHE can be evidently improved by backfilling materials with low and high phase change temperature for summer and winter respectively. At the same time, the energy storage performance can be enhanced by grouting the materials with large latent heat. The study is significant for releasing the thermal interference region of soil and improving the energy storage and heat transfer performance of

  14. Implementation of the Barcelona Basic Model into TOUGH-FLAC for simulations of the geomechanical behavior of unsaturated soils

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, J.; Ijiri, Y.; Yamamoto, H.

    2010-06-01

    This paper presents the implementation of the Barcelona Basic Model (BBM) into the TOUGH-FLAC simulator analyzing the geomechanical behavior of unsaturated soils. We implemented the BBM into TOUGH-FLAC by (1) extending an existing FLAC{sup 3D} module for the Modified Cam-Clay (MCC) model in FLAC{sup 3D} and (2) adding computational routines for suction-dependent strain and net stress (i.e., total stress minus gas pressure) for unsaturated soils. We implemented a thermo-elasto-plastic version of the BBM, wherein the soil strength depends on both suction and temperature. The implementation of the BBM into TOUGH-FLAC was verified and tested against several published numerical model simulations and laboratory experiments involving the coupled thermal-hydrological-mechanical (THM) behavior of unsaturated soils. The simulation tests included modeling the mechanical behavior of bentonite-sand mixtures, which are being considered as back-fill and buffer materials for geological disposal of spent nuclear fuel. We also tested and demonstrated the use of the BBM and TOUGH-FLAC for a problem involving the coupled THM processes within a bentonite-backfilled nuclear waste emplacement tunnel. The simulation results indicated complex geomechanical behavior of the bentonite backfill, including a nonuniform distribution of buffer porosity and density that could not be captured in an alternative, simplified, linear-elastic swelling model. As a result of the work presented in this paper, TOUGH-FLAC with BBM is now fully operational and ready to be applied to problems associated with nuclear waste disposal in bentonite-backfilled tunnels, as well as other scientific and engineering problems related to the mechanical behavior of unsaturated soils.

  15. Coupling mechanism of roof and supporting wall in gob-side entry retaining in fully-mechanized mining with gangue backfilling

    Institute of Scientific and Technical Information of China (English)

    Ma Zhanguo; Gong Peng; Fan Jinquan; Geng Minmin; Zhang Guowei

    2011-01-01

    We analyzed the deformation characteristics of overlying stratum in backfilling with fully-mechanized and retaining roadways along the gob area coal mining technology,and established a mechanical model for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fullymechanized coal mining technology.Using Winkler elastic foundation theory,we analyzed a part of the key stratum under the action of elastic foundation coupling problem,and derived deflection analytical expressions.Combined with specific conditions,we obtained the deflection curves for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fully-mechanized coal mining technology.On this basis,we adopted the Coulomb's earth pressure theory to solve the problem of lateral pressure of the gangue filling area on the supporting wall beside the roadway and to provide the theoretical basis for reasonable selection of the distance between gangue concrete wall and roof and further discussion on the supporting stability of roadway.

  16. Effects of Fine Gangue on Strength, Resistivity, and Microscopic Properties of Cemented Coal Gangue Backfill for Coal Mining

    Directory of Open Access Journals (Sweden)

    Tingye Qi

    2015-01-01

    Full Text Available The cemented coal gangue backfill (CGB in coal mining is normally made of gangue (particle size of 0–15 mm, fly ash, cement, and water. In this study, the effects of the weight content (ranging from 20% to 60% of fine gangue (0–5 mm on the microscopic characteristics, resistivity, and compressive strength of CGB were investigated at 3 d and 28 d curing times, respectively. The test results indicate that the strengths of the CGB, regardless of the curing time, increased with fine gangue content changing from 20% up to 40%. Further increase in fine gangue introduced a decrease in the strength. Another observation is that, at 3 days, a general increasing trend of CGB resistivity was noted with fine gangue content. At 28 days, the resistivity of CGB decreased with increase in the fine gangue content. Correlations between the resistivity and compression strength of CGB show a concave pattern, which attribute to the various micromechanism influenced on the resistivity and strength of CGB with different fine gangue content. It indicates that using resistivity to derive strength of CGB is not appropriate.

  17. Direct methods of soil-structure interaction analysis for earthquake loadings (III)

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, J. B.; Lee, S. R.; Kim, J. M.; Park, K. R.; Choi, J. S.; Oh, S. B. [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1995-06-15

    In this study, direct methods for seismic analysis of soil-structure interaction system have been studied. A computer program 'KIESSI-QK' has been developed based on the finite element technique coupled with infinite element formulation. A substructuring method isolating the displacement solution of near field soil region was adopted. The computer program developed was verified using a free-field site response problem. The post-correlation analysis for the forced vibration tests after backfill of the Hualien LSST project has been carried out. The seismic analyses for the Hualien and Lotung LSST structures have been also performed utilizing the developed computer program 'KIESSI-QK'.

  18. Uptake Mechanisms of Eu(III) on Hydroxyapatite: A Potential Permeable Reactive Barrier Backfill Material for Trapping Trivalent Minor Actinides.

    Science.gov (United States)

    Xu, Lin; Zheng, Tao; Yang, Shitong; Zhang, Linjuan; Wang, Jianqiang; Liu, Wei; Chen, Lanhua; Diwu, Juan; Chai, Zhifang; Wang, Shuao

    2016-04-05

    The permeable reactive barrier (PRB) technique has attracted an increasing level of attention for the in situ remediation of contaminated groundwater. In this study, the macroscopic uptake behaviors and microscopic speciation of Eu(III) on hydroxyapatite (HAP) were investigated by a combination of theoretical modeling, batch experiments, powder X-ray diffraction (PXRD) fitting, and X-ray absorption spectroscopy (XAS). The underlying removal mechanisms were identified to further assess the application potential of HAP as an effective PRB backfill material. The macroscopic analysis revealed that nearly all dissolved Eu(III) in solution was removed at pH 6.5 within an extremely short reaction time of 5 min. In addition, the thermodynamic calculations, desorption experiments, and PXRD and XAS analyses definitely confirmed the formation of the EuPO4·H2O(s) phase during the process of uptake of dissolved Eu(III) by HAP via the dissolution-precipitation mechanism. A detailed comparison of the present experimental findings and related HAP-metal systems suggests that the relative contribution of precipitation to the total Eu(III) removal increases as the P:Eu ratio decreases. The dosage of HAP-based PRB for the remediation of groundwater polluted by Eu(III) and analogous trivalent actinides [e.g., Am(III) and Cm(III)] should be strictly controlled depending on the dissolved Eu(III) concentration to obtain an optimal P:M (M represents Eu, Am, or Cm) ratio and treatment efficiency.

  19. 烧结法赤泥全尾砂胶结充填料%Paste backfilling material prepared with red mud from sintering process and unclassified tailings

    Institute of Scientific and Technical Information of China (English)

    黄迪; 倪文; 祝丽萍

    2012-01-01

    为了解决全尾砂、赤泥大量堆积产生的环境问题,实验采用烧结法赤泥、全尾砂等固体废弃物制备矿山充填料.结果表明:胶结剂的优化配比为赤泥49.2%+矿渣32.8%+熟料10%+石膏8%;充填料强度随着全尾砂掺量的增加而急剧下降;试块在水化初期即出现钙矾石、C-S-H凝胶,这些水化产物对早期强度的提高有很大帮助;差式扫描-热重分析表明试块在水化初期即可固结大量水.烧结法赤泥全尾砂胶结充填料具有早期强度高、固结水量大以及大量利用废料等特点,可满足目前矿山充填的需要.%To solve the problems of environmental pollution brought by the stockpiling of unclassified tailings and red mud, a mine backfilling material was prepared with red mud from sintering process, unclassified tailings and other solid wastes. The experimental results show that the optimal mass proportions of the cementing agent are red mud 49.2% , slag 32.8% , clinker aggregate 10% , and plaster 8% ; the strength of the backfilling material block reduces sharply with the increase of the unclassified tailings addition; the hydration products of cttringite and C-S-H gel generated in the test block at the early stage of hydration help for the early strength. Differential scanning calorimetry-thermo gravimetrie (DSC-TG) analysis shows that the test block concretes lots of water at the early stage. The prepared paste backfilling material has the characteristic of high early strength, large water concretion, high quantity wastes utilization, etc. , and it can meet the requirement of mine backfilling.

  20. 粉煤灰对矿渣胶结充填材料性能的影响%Influence of Fly Ash Performance of Slag Cemented Backfilling Materials

    Institute of Scientific and Technical Information of China (English)

    董璐; 高谦; 南世卿; 何环莎

    2012-01-01

    In view of the features of fly ash as abundant resources,low costs and improving the construction of mortar, the influence of fly ash on strength and liquidity of slag cemented materials is studied through experiments. The results show that the slag cemented backfilling materials with the lime and desulfurization gypsum as the activator, the compressive strength of backfilling body gradually declined with the adding amount of fly ash increasing. 1% of fly ash is added each time,the intensity decreased by 1. 82% at 7 d and by 1. 61% at 28 d on average. Meanwhile,the yield stress and viscosity of the backfilling is getting lower,which indicates that fly ash can largely improve the rheology of backfilling materials,and make high concentration of mortars conveying by gravity flow. Comprehensively considering the strength and the rheology, the optimal dosage of the fly ash ranges from 10% to 20%.%针对粉煤灰具有来源广、价格低廉和能改善砂浆施工性能的特点,研究了粉煤灰对矿渣胶结充填材料强度和流动性的影响.结果表明:在以石灰和脱硫石膏为激发剂制备的矿渣胶凝材料中,随着粉煤灰添加量的不断增大,充填体的抗压强度逐渐下降,每添加1%的粉煤灰,7d强度平均降低1.82%,28 d强度平均降低1.61%;但是充填料的屈服应力和塑形黏度却在不断降低,说明粉煤灰的添加能够很好地改善充填料浆的流变性,实现砂浆高浓度自流输送.综合考虑强度和流变性的影响效果,粉煤灰的最优掺量范围为10%~ 20%.

  1. Stability of submerged rock berms exposed to motion of liquefied soil in waves

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Dixen, Figen Hatipoglu; Fredsøe, Jørgen

    2011-01-01

    The paper describes the results of an experimental study on the behaviour of a submerged rock berm in liquefied backfill soil. The soil is liquefied by waves, and the rock berm is subject to the orbital motion of the liquefied soil. The soil used in the experiments was silt with d50=0.075mm....... Various berm materials were used, stones of size 0.74–2.5cm, plastic balls of size 3.6cm, brass of size 2.5cm and steel of size 1.0cm. The experiments show that rock berms that are stable under very large waves can be unstable when they are exposed to the motion of liquefied soil. The limited data...

  2. Stiffness of Railway Soil-Steel Structures

    Science.gov (United States)

    Machelski, Czesław

    2015-12-01

    The considerable influence of the soil backfill properties and that of the method of compacting it on the stiffness of soil-steel structures is characteristic of the latter. The above factors (exhibiting randomness) become apparent in shell deformation measurements conducted during construction and proof test loading. A definition of soil-shell structure stiffness, calculated on the basis of shell deflection under the service load, is proposed in the paper. It is demonstrated that the stiffness is the inverse of the deflection influence function used in structural mechanics. The moving load methodology is shown to be useful for testing, since it makes it possible to map the shell deflection influence line also in the case of group loads (concentrated forces), as in bridges. The analyzed cases show that the shell's span, geometry (static scheme) and the height of earth fill influence the stiffness of the structure. The soil-steel structure's characteristic parameter in the form of stiffness k is more suitable for assessing the quality of construction works than the proposed in code geometric index ω applied to beam structures. As shown in the given examples, parameter k is more effective than stiffness parameter λ used to estimate the deformation of soil-steel structures under construction. Although the examples concern railway structures, the methodology proposed in the paper is suitable also for road bridges.

  3. M4FT-16LL080303052-State of Knowledge for Colloid Facilitated Radionuclide Transport and Update on Actinide Diffusion in Bentonite Backfill

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences; Joseph, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences

    2016-08-16

    This progress report (Level 4 Milestone Number M4FT-16LL080303052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Disposal R&D Activity Number FT-16LL080303051 and Crystalline International Collaborations Activity Number FT-16LL080303061. The focus of this research is the interaction of radionuclides with Engineered Barrier System (EBS) and host rock materials at various physico-chemical conditions relevant to subsurface repository environments. They include both chemical and physical processes such as solubility, sorption, and diffusion. The colloid-facilitated transport effort focused on preparation of a draft manuscript summarizing the state of knowledge and parameterization of colloid-facilitated transport mechanisms in support of reactive transport and performance assessment models for generic crystalline repositories. This draft manuscript is being submitted as a level 3 milestone with LANL as the primary author. LLNL’s contribution to that effort is summarized only briefly in the present report. A manuscript summarizing long-term U(VI) diffusion experiments through bentonite backfill material was recently accepted for publication; the contents of that manuscript are summarized in the present report. The Np(IV) diffusion experiments were started mid-year and are ongoing. The completion of these experiments is planned for early FY17. Our progress in quantifying Np(IV) diffusion in bentonite backfill is summarized in the present report. Our involvement with the NEA TDB project was summarized in a recent Argillite Disposal activity report. It is not included in this report.

  4. Laboratory determination of migration of Eu(III) in compacted bentonite-sand mixtures as buffer/backfill material for high-level waste disposal.

    Science.gov (United States)

    Zhou, Lang; Zhang, Huyuan; Yan, Ming; Chen, Hang; Zhang, Ming

    2013-12-01

    For the safety assessment of geological disposal of high-level radioactive waste (HLW), the migration of Eu(III) through compacted bentonite-sand mixtures was measured under expected repository conditions. Under the evaluated conditions, advection and dispersion is the dominant migration mechanism. The role of sorption on the retardation of migration was also evaluated. The hydraulic conductivities of compacted bentonite-sand mixtures were K=2.07×10(-10)-5.23×10(-10)cm/s, The sorption and diffusion of Eu(III) were examined using a flexible wall permeameter for a solute concentration of 2.0×10(-5)mol/l. The effective diffusion coefficients and apparent diffusion coefficients of Eu(III) in compacted bentonite-sand mixtures were in the range of 1.62×10(-12)-4.87×10(-12)m(2)/s, 1.44×10(-14)-9.41×10(-14)m(2)/s, respectively, which has a very important significance to forecast the relationship between migration length of Eu(III) in buffer/backfill material and time and provide a reference for the design of buffer/backfill material for HLW disposal in China.

  5. 山东煤炭工业充填开采研究与实践%Research and practice on backfill mining in Shandong coal industry

    Institute of Scientific and Technical Information of China (English)

    乔乃琛

    2015-01-01

    为了推进煤炭工业绿色发展、煤炭清洁高效利用,促进煤炭工业循环可持续发展,分析、研究了山东省煤炭行业实施充填开采的必要性和可行性,通过多种途径转变煤炭生产方式,优化、引导、规范和扶持煤炭企业实施充填开采。%In order to promoting green development of coal industry,efficient utilization of clean coal mining and sustainable development of coal industry circle,the authors introduced and studied necessity and feasibility of backfill mining in Shandong coal industry,furthermore,ac-cording to various channels to change coal production mode,and also optimized,guided,stand-ardized and supported implement backfill mining for coal enterprises.

  6. M4FT-16LL080303052-State of Knowledge for Colloid Facilitated Radionuclide Transport and Update on Actinide Diffusion in Bentonite Backfill

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences; Joseph, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences

    2016-08-16

    This progress report (Level 4 Milestone Number M4FT-16LL080303052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Disposal R&D Activity Number FT-16LL080303051 and Crystalline International Collaborations Activity Number FT-16LL080303061. The focus of this research is the interaction of radionuclides with Engineered Barrier System (EBS) and host rock materials at various physico-chemical conditions relevant to subsurface repository environments. They include both chemical and physical processes such as solubility, sorption, and diffusion. The colloid facilitated transport effort focused on preparation of a draft manuscript summarizing the state of knowledge and parameterization of colloid facilitated transport mechanisms in support of reactive transport and performance assessment models for generic crystalline repositories. This draft manuscript is being submitted as a level 3 milestone with LANL as the primary author. LLNL’s contribution to that effort is summarized only briefly in the present report. A manuscript summarizing longterm U(VI) diffusion experiments through bentonite backfill material was recently accepted for publication; the contents of that manuscript are summarized in the present report. The Np(IV) diffusion experiments were started mid-year and are ongoing. The completion of these experiments is planned for early FY17. Our progress in quantifying Np(IV) diffusion in bentonite backfill is summarized in the present report. Our involvement with the NEA TDB project was summarized in a recent Argillite Disposal activity report. It is not included in this report.

  7. Aespoe Hard Rock Laboratory. Prototype repository. Analyses of microorganisms, gases, and water chemistry in buffer and backfill, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara [Microbial Analytics Sweden AB, Moelnlycke (Sweden)

    2011-06-15

    therefore divided into seven sampling groups, each with similar properties. The properties of one sampling group (i.e. KBU10002 + KBU10008) resembled those of the groundwater, while others (i.e. KBU10004 + KBU10006, KBU10005, and KFA01-KFA04) differed, for example, in microbial composition, salinity, sulphate content, and the concentrations of calcium, potassium, magnesium, sodium, and many dissolved metals, actinides, and lanthanides. One sampling group comprised sampling points that seemed to be in contact with tunnel air (KBU10003 + KBU10007). Another sampling group comprised sampling points, near the canisters in the buffer (KB513-614), with very little pore water with high pH and a high salt content. One sampling point in the backfill, which had not been reached by the groundwater as of May 2007 (KBU10001), now yielded pore water with properties resembling those of groundwater. The gas composition in the sampling groups was uniform in that the proportion of nitrogen in the extracted gas was increasing while the oxygen content was decreasing with time. ATP analyses demonstrated that the biomass in the Prototype was higher than in the surrounding groundwater. The microbiological results indicated that aerobic microbes, such as methane-oxidizing bacteria and culturable heterotrophic bacteria, thrived in the aerobic Prototype environment. The chemical data indicated differences between the sampling groups: concentrations of sodium and potassium were higher in the Prototype pore water than in the groundwater outside it, while calcium was lower than in the groundwater. Obviously, cation exchange occurs in the montmorillonite interlayers. At sampling points containing active microbes, copper, rubidium, vanadium, and uranium were enriched up to 225 times the groundwater levels; microbes are possibly responsible for dissolving these substances by excreting compound-specific ligands. Overall, the observations presented here strongly support our hypothesis that oxygen will be

  8. Aespoe Hard Rock Laboratory. Prototype Repository. Analyses of microorganisms, gases and water chemistry in buffer and backfill, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara (Microbial Analytics Sweden AB (Sweden))

    2010-09-15

    chemistry. The in 2007 improved sampling and analysis protocols worked very well. Also, the molecular methods that were tested for the first time in the Prototype showed promising potential. IPR 08-01 revealed that many of the hydrochemical sampling points differ quite remarkably from each other. The 16 sampling points were therefore divided into seven sampling groups with similar properties. The properties of one sampling group (i.e., KBU10002+8) resembled those of the groundwater, while others (i.e., KBU10004+6, KBU10005, and KFA01-04) differed, for example, in microbial composition, salinity, sulphate content, pH, and the concentrations of calcium, potassium, magnesium, sodium, and many dissolved metals, actinides, and lanthanides. One sampling group contained sampling points that seemed to be in contact with tunnel air (KBU10003+7). Another sampling group contained sampling points near the canisters in the buffer (KB513-614) with very little pore water with high pH and a high salt content. One sampling point in the backfill, which had not been reached by the groundwater as of May 2007 (KBU10001), now consisted of pore water with properties resembling those of groundwater. The gas composition in the sampling groups was uniform in that the proportion of nitrogen in the extracted gas was increasing and the oxygen content decreasing with time. In most sampling groups, the oxygen content in the pore water had decreased from 3-7% as of May 2007 to 0.6-4% in 2009. This can also be compared with the proportion of oxygen in the gas phase in 2005, which was 10-18%. Hydrogen, methane, helium, and carbon dioxide concentrations varied, especially in the sampling groups with extractable pore water. ATP analyses demonstrated that the biomass in the Prototype repository is high compared to the surrounding groundwater. The microbiological results indicated that aerobic microbes, such as MOB and CHAB, thrived in the aerobic Prototype environment

  9. Ore Dilution Prediction of Ore Drawing below Backfilling of Waste Rock Layer and Particle Flow Numerical Analysis%回填废石层下放矿损贫预测及颗粒流数值分析

    Institute of Scientific and Technical Information of China (English)

    刘增辉; 高谦; 李欣; 李俊华

    2011-01-01

    When open-air is transferred to underground mining, the backfilling of waste rock layer has a certain impact on ore loss and dilution in the ore drawing process. There are three main factors of ore loss and dilution below backfilling of waste rock layer, backfilling thickness, and particle size of waste rock layer and its non-uniformal level Through reprocesslng the experimental data from different tests ,the paper summed up the mathematical model of ore loss and dilution rate below the backfilling of waste rock layer. Combining with transition from open-pit to underground mining in stope Ⅲ of Sijiaying iron mine,the non-uniformity and particle size of the backfilling of waste rock layer are designed. Through the orthogonal experimental method of particle flow numerical simulation,the relationship of such four factors as ore dilution ratio λ,backfilling thickness h, particle diameter d, particle non-uniformity K of waste rock layer with the ore loss rate is set up,which provides a reference for the rational design of backfilling layer in similar conditions.%露天转地下开采,回填废石层在放矿过程中对矿石的损失和贫化有一定的影响.回填废石层下放矿损贫的主要影响因素有回填层厚度、废石的粒径和非均匀度3个方面,对不同试验者的实验数据重新处理,总结出了回填废石层下放矿贫化率和损失率的数学模型,并结合司家营铁矿Ⅲ采场的露天转地下工程进行了回填废石粒径与非均匀度的设计.通过颗粒流数值正交试验方法,分别从绝对因素和相对因素回归建立了贫化率λ、回填层厚度h、回填层粒径d、回填层粒径非均匀度K4个因素和损失率之间的关系,为类似条件下的回填层合理设计提供参考.

  10. Influence of pressure conditions and back-filling materials on the durability of bore-hole ground loops; Lebensdauer von Erdwaermesonden in Bezug auf Druckverhaeltnisse und Hinterfuellung

    Energy Technology Data Exchange (ETDEWEB)

    Rohner, R. [E. Rohner, Arnegg (Switzerland); Rybach, L.; Salton, M. [Swiss Federal Institute of Technology (ETHZ), Institut fuer Geophysik, Zuerich (Switzerland)

    2001-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) discusses the influence of the relatively high pressures found in ground loops at depths of more than 200 metres and the effects caused by overloading the ground loops. The latter can cause the back-filling between the ground loop and the surrounding rock to freeze. The report describes tests carried out on 70-metre and 265-metre deep test bore-hole installations. The results of investigations into the influence of such pressure conditions on the materials of the ground loop and their service life are presented. The results are also compared with simulations using the FRACTure and EED calculation programmes. Details are given on the bore-holes with respect to their geology and construction. The report concludes that bore-hole ground loops can be considered as being very robust components with a long service life, provided they are designed and installed according to accepted professional standards.

  11. Strength evolution and deformation behaviour of cemented paste backfill at early ages:Effect of curing stress, filling strategy and drainage

    Institute of Scientific and Technical Information of China (English)

    Ghirian Alireza; Fall Mamadou⇑

    2016-01-01

    In this study, a pressure cell apparatus is developed to investigate the early age evolution of the strength and deformation behaviour of cemented paste backfill (CPB) when subjected to various loading condi-tions under different curing scenarios. The different curing scenarios that are simulated include: (1) drained and undrained conditions, (2) different filling rates, (3) different filling sequences, and (4) differ-ent curing stresses. The findings show that drainage, curing stress, curing time and filling rate influence the mechanical and deformation behaviours of CPB materials. The coupled effects of consolidation, drai-nage and suction contribute to the strength development of drained CPB subjected to curing stress. On the other hand, particle rearrangement caused by the applied pressure and suction development due to self-desiccation plays a significant role in the strength gain of undrained CPB cured under stress. Furthermore, curing stress induces slightly faster rate of cement hydration, which can contribute to strength acquisition.

  12. Aespoe Hard Rock Laboratory. Prototype repository. Analyses of microorganisms, gases, and water chemistry in buffer and backfill, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara [Microbial Analytics Sweden AB, Moelnlycke (Sweden)

    2011-06-15

    therefore divided into seven sampling groups, each with similar properties. The properties of one sampling group (i.e. KBU10002 + KBU10008) resembled those of the groundwater, while others (i.e. KBU10004 + KBU10006, KBU10005, and KFA01-KFA04) differed, for example, in microbial composition, salinity, sulphate content, and the concentrations of calcium, potassium, magnesium, sodium, and many dissolved metals, actinides, and lanthanides. One sampling group comprised sampling points that seemed to be in contact with tunnel air (KBU10003 + KBU10007). Another sampling group comprised sampling points, near the canisters in the buffer (KB513-614), with very little pore water with high pH and a high salt content. One sampling point in the backfill, which had not been reached by the groundwater as of May 2007 (KBU10001), now yielded pore water with properties resembling those of groundwater. The gas composition in the sampling groups was uniform in that the proportion of nitrogen in the extracted gas was increasing while the oxygen content was decreasing with time. ATP analyses demonstrated that the biomass in the Prototype was higher than in the surrounding groundwater. The microbiological results indicated that aerobic microbes, such as methane-oxidizing bacteria and culturable heterotrophic bacteria, thrived in the aerobic Prototype environment. The chemical data indicated differences between the sampling groups: concentrations of sodium and potassium were higher in the Prototype pore water than in the groundwater outside it, while calcium was lower than in the groundwater. Obviously, cation exchange occurs in the montmorillonite interlayers. At sampling points containing active microbes, copper, rubidium, vanadium, and uranium were enriched up to 225 times the groundwater levels; microbes are possibly responsible for dissolving these substances by excreting compound-specific ligands. Overall, the observations presented here strongly support our hypothesis that oxygen will be

  13. Numerical Simulation of Hysteretic Live Load Effect in a Soil-Steel Bridge

    Directory of Open Access Journals (Sweden)

    Sobótka Maciej

    2014-03-01

    Full Text Available The paper presents numerical simulation of hysteretic live load effect in a soil-steel bridge. The effect was originally identified experimentally by Machelski [1], [2]. The truck was crossing the bridge one way and the other in the full-scale test performed. At the same time, displacements and stress in the shell were measured. The major conclusion from the research was that the measured quantities formed hysteretic loops. A numerical simulation of that effect is addressed in the present work. The analysis was performed using Flac finite difference code. The methodology of solving the mechanical problems implemented in Flac enables us to solve the problem concerning a sequence of load and non-linear mechanical behaviour of the structure. The numerical model incorporates linear elastic constitutive relations for the soil backfill, for the steel shell and the sheet piles, being a flexible substructure for the shell. Contact zone between the shell and the soil backfill is assumed to reflect elastic-plastic constitutive model. Maximum shear stress in contact zone is limited by the Coulomb condition. The plastic flow rule is described by dilation angle ψ = 0. The obtained results of numerical analysis are in fair agreement with the experimental evidence. The primary finding from the performed simulation is that the slip in the interface can be considered an explanation of the hysteresis occurrence in the charts of displacement and stress in the shell.

  14. Examination of the behavior of gravity quay wall against liquefaction under the effect of wall width and soil improvement.

    Science.gov (United States)

    Firoozi, Ali Akbar; Taha, Mohd Raihan; Mir Moammad Hosseini, S M; Firoozi, Ali Asghar

    2014-01-01

    Deformation of quay walls is one of the main sources of damage to port facility while liquefaction of backfill and base soil of the wall are the main reasons for failures of quay walls. During earthquakes, the most susceptible materials for liquefaction in seashore regions are loose saturated sand. In this study, effects of enhancing the wall width and the soil improvement on the behavior of gravity quay walls are examined in order to obtain the optimum improved region. The FLAC 2D software was used for analyzing and modeling progressed models of soil and loading under difference conditions. Also, the behavior of liquefiable soil is simulated by the use of "Finn" constitutive model in the analysis models. The "Finn" constitutive model is especially created to determine liquefaction phenomena and excess pore pressure generation.

  15. Determination of internal pressure and the backfill gas composition of nuclear fuel rods; Determinacion de la presion interna y la composicion del gas de llenado de barras de combustible nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Garcia C, M.A.; Cota S, G.; Merlo S, L.; Fernandez T, F. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    An important consideration in the nuclear fuel manufacturing is the measurement of the helium atmosphere pressure and its composition analysis inside the nuclear fuel rod. In this work it is presented a system used to measure the internal pressure and to determine the backfill gas composition of fuel rods. The system is composed of an expansion chamber provided of a seals system to assure that when rod is drilled, the gas stays contained inside the expansion chamber. The system is connected to a pressure measurement digital system: Baratron MKS 310-AHS-1000. Range 1000 mm Hg from which the pressure readings are taken when this is stabilized in all the system. After a gas sample is sent toward a Perkin Elmer gas chromatograph, model 8410 with thermal conductivity detector to get the corresponding chromatogram and doing the necessary calculations for obtaining the backfill gas composition of the rod in matter. (Author)

  16. Environmental projects. Volume 14: Removal of contaminated soil and debris

    Science.gov (United States)

    Kushner, Len

    1992-01-01

    Numerous diverse activities at the Goldstone Deep Space Communications Complex (GDSCC) are carried out in support of six parabolic dish antennas. Some of these activities can result in possible spills or leakages of hazardous materials and wastes stored both above ground in steel drums and below ground in underground storage tanks (UST's). These possible leaks or spills, along with the past practice of burial of solid debris and waste in trenches and pits, could cause local subsurface contamination of the soil. In 1987, the Jet Propulsion Laboratory (JPL), retained Engineering-Science, Inc. (E-S), Pasadena, California, to identify the specific local areas within the GDSCC with subsurface soil contamination. The E-S study determined that some of the soils at the Apollo Site and the Mars Site were contaminated with hydrocarbons, while soil at a nonhazardous waste dumpsite at the Mojave Base site was contaminated with copper. This volume is a JPL-expanded version of the PE209 E-S report, and it also reports that all subsurface contaminated soils at the GDSCC were excavated, removed, and disposed of in an environmentally acceptable way, and the excavations were backfilled and covered in accordance with accepted Federal, State, and local environmental rules and regulations.

  17. Analysis of Impacts on Earthquake Response of Intake Tower by Backfill Concrete on Tower Back%塔背回填混凝土对进水塔地震响应的影响分析

    Institute of Scientific and Technical Information of China (English)

    李锋

    2015-01-01

    塔背回填混凝土将岸塔式进水塔和山岩连成一体,提高了进水塔整体刚度,有效改善了塔体在地震情况下的拉应力幅值,对进水塔结构的抗震设计非常关键。以某水电站的岸塔式进水塔为例,针对不同高度塔背回填混凝土的塔体模型进行三维有限元静动力计算,以分析回填混凝土对进水塔地震响应的影响。%The backfill concrete on the tower back integrates the intake tower and the mountain rockmass, increasing the overall rigidity of the intake tower and effectively improving the tensile stress range value of the tower body in earthquake condition.This is very important for the aseismic design of the intake tower structure.With the case of the intake tower of one hydropower station, the static and dynamic calculations in 3D finite element method are performed to the tower models with the backfill concrete on the tower back at different heights so as to analyze the impacts on the earthquake response of the intake tower by the backfill concrete on the tower back.

  18. 核子密度仪在阿曼管沟回填中的应用%Use of nuclear density gauge for testing trench backfilling in Oman

    Institute of Scientific and Technical Information of China (English)

    邓兆勋; 刘光然

    2011-01-01

    针对国际工程——阿曼马斯喀特污水管网工程点多、面广、管沟回填速度快、检测频率高等特点,阐述了核子密度仪的工作原理,依据英国BS标准进行校正的方法及针对阿曼政府对辐射源的管理所采取的防护措施,保证了工程质量和施工的顺利进行。%Considering Oman Muscat waste water collection network project——an international construction project which has many engineering aspects,requirement of quick backfilling and fast detection,high test frequencies,this article explains the working principle of the nuclear density gauge,according to the British BS standard method of correction and focusing on the management of the government of Oman to the radiation protection measures taken to ensure the engineering quality and construction to proceed smoothly.

  19. Research and Development of a New Silica-Alumina Based Cementitious Material Largely Using Coal Refuse for Mine Backfill, Mine Sealing and Waste Disposal Stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Henghu Sun; Yuan Yao

    2012-06-29

    Coal refuse and coal combustion byproducts as industrial solid waste stockpiles have become great threats to the environment. To activate coal refuse is one practical solution to recycle this huge amount of solid waste as substitute for Ordinary Portland Cement (OPC). The central goal of this project is to investigate and develop a new silica-alumina based cementitious material largely using coal refuse as a constituent that will be ideal for durable construction, mine backfill, mine sealing and waste disposal stabilization applications. This new material is an environment-friendly alternative to Ordinary Portland Cement. The main constituents of the new material are coal refuse and other coal wastes including coal sludge and coal combustion products (CCPs). Compared with conventional cement production, successful development of this new technology could potentially save energy and reduce greenhouse gas emissions, recycle vast amount of coal wastes, and significantly reduce production cost. A systematic research has been conducted to seek for an optimal solution for enhancing pozzolanic reactivity of the relatively inert solid waste-coal refuse in order to improve the utilization efficiency and economic benefit as a construction and building material.

  20. Soils - NRCS Web Soil Survey

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Web Soil Survey (WSS) provides soil data and information produced by the National Cooperative Soil Survey. It is operated by the USDA Natural Resources Conservation...

  1. Soil Segregation Methods for Reducing Transportation and Disposal Costs - 13544

    Energy Technology Data Exchange (ETDEWEB)

    Frothingham, David; Andrews, Shawn; Barker, Michelle; Boyle, James; Buechi, Stephen; Graham, Marc; Houston, Linda; Polek, Michael; Simmington, Robert; Spector, Harold [U.S. Army Corps of Engineers, Buffalo District, 1776 Niagara St., Buffalo, NY 14207 (United States); Elliott, Robert ' Dan' [U.S. Army Reserve, 812A Franklin St.,Worcester, MA 01604 (United States); Durham, Lisa [Argonne National Laboratory, Environmental Science Division, 9700 S. Cass Ave., Argonne, IL 60439 (United States)

    2013-07-01

    At Formerly Utilized Sites Remedial Action Program (FUSRAP) sites where the selected alternative for contaminated soil is excavation and off-site disposal, the most significant budget items of the remedial action are the costs for transportation and disposal of soil at an off-site facility. At these sites, the objective is to excavate and dispose of only those soils that exceed derived concentration guideline levels. In situ soil segregation using gross gamma detectors to guide the excavation is often challenging at sites where the soil contamination is overlain by clean soil or where the contaminated soil is located in isolated, subsurface pockets. In addition, data gaps are often identified during the alternative evaluation and selection process, resulting in increased uncertainty in the extent of subsurface contamination. In response, the U.S. Army Corps of Engineers, Buffalo District is implementing ex situ soil segregation methods. At the remediated Painesville Site, soils were excavated and fed through a conveyor-belt system, which automatically segregated them into above- and below-cleanup criteria discharge piles utilizing gamma spectroscopy. At the Linde Site and the Shallow Land Disposal Area (SLDA) Site, which are both in the remediation phase, soils are initially segregated during the excavation process using gross gamma detectors and then transported to a pad for confirmatory manual surveying and sampling. At the Linde Site, the ex situ soils are analyzed on the basis of a site-specific method, to establish compliance with beneficial reuse criteria that were developed for the Linde remediation. At the SLDA Site, the ex situ soils are surveyed and sampled based on Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) final status survey guidance to demonstrate compliance with the derived concentration guideline levels. At all three sites, the ex situ soils that meet the site- specific DCGLs are retained on-site and used as backfill

  2. Site-specific analysis of radiological and physical parameters for cobbly soils at the Gunnison, Colorado, processing site

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    The remedial action at the Gunnison, Colorado, processing site is being performed under the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978 [Public Law (PL) 95-6041]. Under UMTRCA, the US Environmental Protection Agency (EPA) is charged with the responsibility of developing appropriate and applicable standards for the cleanup of radiologically contaminated land and buildings at 24 designated sites, including the Gunnison, Colorado, inactive processing site. The remedial action at the processing site will be conducted to remove the tailings and contaminated materials to meet the EPA bulk soil cleanup standards for surface and subsurface soils. The site areas disturbed by remedial action excavation will be either contoured or backfilled with radiologically uncontaminated soil and contoured to restore the site. The final contours will produce a final surface grade that will create positive drainage from the site.

  3. 赤泥膏体和似膏体全尾砂胶结充填料研究%Research on Whole- tailings Paste and Paste -like Backfilling Material with Red Mud

    Institute of Scientific and Technical Information of China (English)

    祝丽萍; 倪文; 黄迪; 黄晓燕; 王中杰

    2011-01-01

    实验以赤泥、水淬高炉矿渣、脱硫石膏、全尾砂和少量水泥熟料制备出一种新型的膏体和似膏体全尾砂胶结充填材料,通过对体系质量浓度的考察,得出了质量浓度(水胶比)一坍落度、坍落度一强度关系曲线。膏体全尾砂胶结充填料的合适的质量浓度为79.4%~81.9%,所制备的试块60d强度达到4~6MPa;似膏体胶结充填料的合适的质量浓度为78.0%左右,所制备的试块60d强度为4MPa左右。通过SEM分析表明,该充填料固化后形成絮状和团簇状的胶体以及针棒状的石膏和钙矾石,它们团聚交织在一起形成小仙人球状的结构填充在尾砂颗粒%A new paste and paste -like backfilling material was prepared with red mud,quenched blast furnace slag, desulphuri- zation gypsum,wholetailings and a little cement clinker. With the different concentration of the slurry, the relationship between mass concentration and slump as well as the relation of slump and strength were obtained. The results of the experiment indicated that the appropriate concentration of the cemented whole - tailings backfilling paste was 79.4% - 81.9% and its compres sive strength of 60 days was 4 to 6 MPa ; the appropriate concen tration of the cemented paste - like backfilling was 78.0% and its compressive strength of 60 days reached about 4 MPa. By scanning electron microscope ( SEM ) , flocculence - shaped and cluster - shaped C - S - H as well as the needle - like gypsum and ettringite were observed. They reunited together to form somesmall cactiballs and the cactiballs filled up the gap between the tailings,which enhance the connection between the phase and the matrix phase. The backfilling material reported in this paper also has some excellent properties, such as good working performance,low cost and high strength.

  4. Successful Implementation of Soil Segregation Technology at the Painesville FUSRAP Site - 12281

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, Stephen P.; Andrews, Shawn M. [U.S. Army Corps of Engineers, Buffalo District, Buffalo, New York (United States); Lombardo, Andrew J. [Safety and Ecology Corporation, Beaver, Pennsylvania (United States); Lively, Jeffrey W. [AMEC Environment and Infrastructure, Grand Junction, Colorado (United States)

    2012-07-01

    Typically the highest cost component of the radiological soils remediation of Formerly Utilized Sites Remedial Action Program (FUSRAP) sites is the cost to transport and dispose of the excavated soils, typically contaminated with naturally occurring isotopes of uranium, thorium and radium, at an appropriately permitted off-site disposal facility. The heterogeneous nature of the contamination encountered at these sites makes it difficult to accurately delineate the extent of contaminated soil using the limited, discrete sampling data collected during the investigation phases; and difficult to precisely excavate only the contaminated soil that is above the established cleanup limits using standard in-field scanning and guiding methodologies. This usually results in a conservative guided excavation to ensure cleanup criteria are met, with the attendant transportation and disposal costs for the larger volumes of soil excavated. To address this issue during the remediation of the Painesville FUSRAP Site, located in Painesville, Ohio, the Buffalo District of the U.S. Army Corps of Engineers, and its contractor, Safety and Ecology Corporation (SEC), employed automatic soil segregation technology provided by MACTEC (now AMEC) to reduce the potential for transportation and disposal of soils that met the cleanup limits. This waste minimization technology utilized gamma spectroscopy of conveyor-fed soils to automatically segregate the material into above and below criteria discharge piles. Use of the soil segregation system resulted in cost savings through the significant reduction of the volume of excavated soil that required off-site transportation and disposal, and the reduction of the amount of imported clean backfill required via reuse of 'below criteria' segregated soil as place back material in restoring the excavations. Measurements taken by the soil segregation system, as well as results of quality control sampling of segregated soils, confirmed that soils

  5. Modeling of Coupled Thermo-Hydro-Mechanical Processes with Links to Geochemistry Associated with Bentonite-Backfilled Repository Tunnels in Clay Formations

    Science.gov (United States)

    Rutqvist, Jonny; Zheng, Liange; Chen, Fei; Liu, Hui-Hai; Birkholzer, Jens

    2014-01-01

    This paper presents simulation results related to coupled thermal-hydraulic-mechanical (THM) processes in engineered barrier systems (EBS) and clay host rock, in one case considering a possible link to geochemistry. This study is part of the US DOE Office of Nuclear Energy's used fuel disposition campaign, to investigate current modeling capabilities and to identify issues and knowledge gaps associated with coupled THMC processes and EBS-rock interactions associated with repositories hosted in clay rock. In this study, we simulated a generic repository case assuming an EBS design with waste emplacement in horizontal tunnels that are back-filled with bentonite-based swelling clay as a protective buffer and heat load, derived for one type of US reactor spent fuel. We adopted the Barcelona basic model (BBM) for modeling of the geomechanical behavior of the bentonite, using properties corresponding to the FEBEX bentonite, and we used clay host rock properties derived from the Opalinus clay at Mont Terri, Switzerland. We present results related to EBS host-rock interactions and geomechanical performance in general, as well as studies related to peak temperature, buffer resaturation and thermally induced pressurization of host rock pore water, and swelling pressure change owing to variation of chemical composition in the EBS. Our initial THM modeling results show strong THM-driven interactions between the bentonite buffer and the low-permeability host rock. The resaturation of the buffer is delayed as a result of the low rock permeability, and the fluid pressure in the host rock is strongly coupled with the temperature changes, which under certain circumstances could result in a significant increase in pore pressure. Moreover, using the BBM, the bentonite buffer was found to have a rather complex geomechanical behavior that eventually leads to a slightly nonuniform density distribution. Nevertheless, the simulation shows that the swelling of the buffer is functioning to

  6. Study on Wear Mechanism of Paste Backfilling Pipeline in Deep Mining%深井开采膏体充填管线磨损机理研究

    Institute of Scientific and Technical Information of China (English)

    吴顺江; 容宇

    2012-01-01

    会泽铅锌矿开采深度超过1000m,属深井开采.主要采用膏体充填处理采空区,由于长时间膏体料浆摩擦管壁,管线磨损严重甚至磨穿管壁,导致部分浆液外淤,管道卸压会导致堵管事故的发生,堵管次数随着管线的磨蚀呈上升趋势.通过研究发现,影响管线磨损的因素包括固体颗粒粒级组成、形状、浆体的性质、粘度、流速及管材质量等.在充填过程中,通过对提高膏体浓度、增加管线输送阻力和改变尾砂粒级组成等进行分析,结合现场实验,提出了合理解决管线磨损和延长管线寿命的一系列措施,取得了较好的效果.%The mining depth of Huize lead &zinc ore deposit is more than 1 000 m, it belongs to deep mining. The goaf is mainly treated by paste backfilling; the tube wall has been severe worn, even wore out, due to the friction of pipe wall by paste slurry for a long time, which give rise to external silting of partial slurry, so that pressure relief of pipeline can generate pipe blockage, the times of pipe blockage showed an increasing tendency following with the abrasion of pipeline. The research results showed that the influencing factor of pipeline abrasion includes: the particle size compositions of solid particle, shape, the property, viscosity, flow velocity of slurry and tube quality, etc. According to the analysis of paste concentration increasing, pipeline transport resistance increasing and changing of tailings' size fraction composition, etc. And combining with the field experiment, a series measures is proposed to rationally solve the problems of pipeline abrasion and lengthen the service life of pipeline, and good effect is obtained.

  7. Soil formation.

    NARCIS (Netherlands)

    Breemen, van N.; Buurman, P.

    1998-01-01

    Soil Formation deals with qualitative and quantitative aspects of soil formation (or pedogenesis) and the underlying chemical, biological, and physical processes. The starting point of the text is the process - and not soil classification. Effects of weathering and new formation of minerals, mobilis

  8. Soil metagenomics and tropical soil productivity

    OpenAIRE

    Karen A Garrett

    2009-01-01

    This presentation summarizes research in the soil metagenomics cross cutting research activity. Soil metagenomics studies soil microbial communities as contributors to soil health.C CCRA-4 (Soil Metagenomics)

  9. Soils - Volusia County Soils (Polygons)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Soils: 1:24000 SSURGO Map. Polygon boundaries of Soils in Volusia County, downloaded from SJRWMD and created by NRCS and SJRWMD. This data set is a digital version...

  10. 南水北调中线工程改性土余料再利用研究%Research on re-utilization of surplus modified soil in Middle Route Project of South to North Water Diversion

    Institute of Scientific and Technical Information of China (English)

    张胜明; 王德云; 刘勇

    2014-01-01

    The useable soil sources for the most bidding sections of Middle Route Project of South to North Water Diversion are insufficient and using cement-mixed modified soil to replace the canal soil is a main measure for guaranteeing the canal slope stability. In the backfilling construction, large amount of surplus modified soil was produced after slope cutting and the indoor and field tests discovered that the surplus modified soil could be used as backfilling soil. In the test, the selection method of the maxi-mum dry density, construction technology and application scope of the modified soil were determined. The soil re-utilization has increased backfilling soil sources in weak expansive soil area, which could save farmland, resources and protect environment.%南水北调中线工程大部分标段可用土料源不足,采用弱膨胀土掺入水泥(简称水泥改性土,下同)后对膨胀土渠段进行换填施工,是确保膨胀土渠段边坡稳定的主要措施之一。在填筑施工中,按设计坡比削坡后产生大量的改性土削坡余料,通过室内试验及现场试验验证了改性土余料亦可用于工程回填。为此,确定了改性土余料最大干密度的选择方法、改性土余料的施工工艺及使用部位。对余料土的再利用,保证了弱膨胀土地区土方施工的回填料源,避免或减少了农田占压面积,取得了节约资源与保护环境的双重效果。

  11. Soil infiltrometer

    Energy Technology Data Exchange (ETDEWEB)

    Mehler, M.R.

    1990-09-18

    This patent describes an infiltrometer useful for field testing soil permeability. It comprises: a large reservoir having an open bottom resting on the soil; a small reservoir having an open bottom resting on the soil, the small reservoir being positioned within the large reservoir; the small reservoir comprising a relatively large receptacle adjacent the soil and a relatively small receptacle connected thereto and extending upwardly therefrom; the volume of the large reservoir greatly exceeding the volume of the small reservoir; the ratio of the upper surface area of liquid in the large reservoir to the surface area of the soil covered thereby greatly exceeding the ratio of the upper surface area of liquid in the relatively small receptacle of the small reservoir to the surface area of the soil covered thereby; and means for determining the amount of liquid from the small reservoir permeating into the soil.

  12. Effects of Superplasticizer on Transport Properties of Backfill Slurry Contained Bittern%高效减水剂对含盐卤充填料浆输送特性的影响

    Institute of Scientific and Technical Information of China (English)

    王昆; 杨鹏; 吕文生; 刘杰; 张浩

    2016-01-01

    With the special geological and hydrological conditions of Sanshandao gold mine,there were large amounts of bittern ions in backfill mixing water according to the test results,which has an adverse effect in slurry gravity transportation. The possibility of using superplasticizer to improve slurry transportation properties was explored in this paper to realize high concentration gravity transportation. The backfill slurry was prepared with using classified tailings,backfill water,cement and adding different kinds and amounts of superplasticizer. The slurry settling and bleeding rates were tested by standing in the measuring cylinder. And the rheological properties were tested by using R/S-SST rheometer. The influence law of superplastici-zer on slurry settling and rheological properties were revealed by comparative analysis. The results showed:The slurry mixed with 0. 5‰ naphthalene superplasticizer suffered the largest decline in bleeding rates. And it provided an effective way of re-ducing stope dewatering pressure;The slurries with 0. 5‰ naphthalene superplasticizer admixture under high cement-tailings ratio condition and 0. 5‰polycarboxylene superplasticizer admixture under low cement-tailings ratio condition suffered the lar-gest decline in settling rates;The rheological property of backfill slurry contained bittern can be represented as Bingham flow pattern. The best transport efficiency could be achieved by mixing 0. 5‰ polycarboxylene superplasticizer when the slurry vis-cosity and yield stress both showed relatively low values. In conclusion,the suspension of backfill slurry contained bittern could be enhanced by superplasticizer. And the slurry viscosity and yield stress were both effectively reduced. Thus the pipe wall ab-rasion was decreased.%三山岛金矿地质水文条件特殊,测得充填用水中富含盐卤离子,对料浆自流输送造成不利影响。本研究探索使用高效减水剂改善含盐卤料浆的输送特性,以实现

  13. Research on Dynamic Parameters of Soil Sites in the Dalian Area

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaoping; Li Ya; Liu Yang; Jiang Hua; Zhang Yinlong; Huang Yimo

    2012-01-01

    In this paper, dynamic soil parameters derived from Dalian area seismic risk assessment reports are collected. In this study, the measurement data is divided into 7 types, i.e. silty clay, muddy silty clay, clay, medium sand, rock fragments, backfill soil and fully- weathered slate. Statistics of the dynamic parameters of these soils are carried out to obtain the mean values of dynamic shear modulus ratio and damping ratio. Typical drill holes are selected to establish dynamic soil models to investigate the seismic response for various cases. The dynamic parameters of the models are taken from the statistical values of this study, the standard values of code 94 (i. e. the dynamic soil parameters for Dalian seismic microzonation), and the recommended values by Yuan Xiaoming et al. (2000) respectively. The calculated results of peak ground acceleration are compared with the response spectral characteristics. The results show that the statistical values are approximate to the values recommended by Yuan Xiaoming, et al. (2000), but different greatly with the standard values in code 94.

  14. Soil friability

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl

    2011-01-01

    This review gathers and synthesizes literature on soil friability produced during the last three decades. Soil friability is of vital importance for crop production and the impact of crop production on the environment. A friable soil is characterized by an ease of fragmentation of undesirably large...... aggregates/clods and a difficulty in fragmentation of minor aggregates into undesirable small elements. Soil friability has been assessed using qualitative field methods as well as quantitative field and laboratory methods at different scales of observation. The qualitative field methods are broadly used...... by scientists, advisors and farmers, whereas the quantitative laboratory methods demand specialized skills and more or less sophisticated equipment. Most methods address only one aspect of soil friability, i.e. either the strength of unconfined soil or the fragment size distribution after applying a stress. All...

  15. Soil proteomics

    DEFF Research Database (Denmark)

    Oonk, S.; Cappellini, Enrico; Collins, M.J.

    2012-01-01

    In this work, two sets of experiments were carried out to assess the potential of soil proteomics for archaeological site interpretation. First, we examined the effects of various protein isolation reagents and soil constituents on peptide mass fingerprinting (PMF) of soil-like materials spiked...... with bovine serum albumin (BSA). In a subsequent case study, we assessed the relative age of soils from an ancient clay floor of a Roman farmhouse using amino acid racemization and then applied MALDI-TOF-MS-MS to detect and identify biomarkers for human occupation. The results from the first experiments......) are more susceptible to isolation than other regions and this suggest that soil proteins can be only partly isolated. Soil-protein interactions were also found to inhibit tryptic cleavage of BSA, resulting in an enhanced specificity of BSA peptides. Our results further stress the importance of multiple...

  16. (Contaminated soil)

    Energy Technology Data Exchange (ETDEWEB)

    Siegrist, R.L.

    1991-01-08

    The traveler attended the Third International Conference on Contaminated Soil, held in Karlsruhe, Germany. The Conference was a status conference for worldwide research and practice in contaminated soil assessment and environmental restoration, with more than 1500 attendees representing over 26 countries. The traveler made an oral presentation and presented a poster. At the Federal Institute for Water, Soil and Air Hygiene, the traveler met with Dr. Z. Filip, Director and Professor, and Dr. R. Smed-Hildmann, Research Scientist. Detailed discussions were held regarding the results and conclusions of a collaborative experiment concerning humic substance formation in waste-amended soils.

  17. Study on Preparation, Microstructure and Solidifying Mechanism of Backfill Materials from Mud Solidification%泥浆固化充填材料的制备、微结构及其固化机理的研究

    Institute of Scientific and Technical Information of China (English)

    彭美勋; 蒋建宏; 王正红; 申少华

    2011-01-01

    应用复合胶凝剂制备红壤土泥浆充填材料,利用正交实验方法研究了胶凝剂组分对充填体强度的影响,并运用扫描电镜和X射线衍射技术探讨了固化机理.泥浆固化体早期(3d和7d)强度高,后期(28 d)强度稳定增长.其中硫铝酸盐熟料、石灰和硬石膏的总加量对固化体各龄期强度的影响最为显著;水玻璃与烧碱的加量对固化体的早期强度增长有益,但对后期强度有一定的负面影响;矿渣和硅灰对固化体后期抗压强度有明显贡献.对粘土进行离子交换,并在水化过程不同阶段生成C-S-H凝胶与高结晶水含量的钙矾石是复合胶凝剂的固化机理.%Backfill materials were prepared for mud using complex gel agents. The effects of the components on the strength of the backfill materials were studied with orthogonal experiment methods and the solidification mechanism of the backfill materials were discussed by SEM and XRD technologies. The mud solidification specimens exhibited high compressive strength at early period (3d and 7 d) that developed stably at later period (28 d). The content of sulphoaluminate cement clinker, lime and anhydrite significantly affected the compressive strength at every period, and the content of water glass and caustic soda were beneficial to improve the compressive strength at early period but negative to that at later period somewhat. The slag and silica fume obviously contributed to the development of the compressive strength. The solidification mechanisms of the complex gel agents were proposed based on the ion exchange with the mud and the generation of the C-S-H gelatin and ettringite containing high content of crystal water.

  18. 高瓦斯矿井高水材料充填墩柱沿空留巷技术%Gateway Retained Along Goaf Technology with Pier Pillar Backfilled with High Water Material in High Gassy Mine

    Institute of Scientific and Technical Information of China (English)

    史国跃

    2014-01-01

    In order to improve a high timber consumption,high labor intensity,complicated construction and low support strength of the timber pack gateway retained along the goaf,a high water material was applied to backfill the pier pillar for the gateway retained along the goaf technology in Gaohe Mine and the industrial trial was conducted in No. E1302 air return gateway.The results showed that the max convergence between the roof and floor of the timber pack gateway retained along the goaf was 286 mm,the max convergence between the roof and floor of the gateway retained along the goaf with the pier pillar backfilled with the high water material was 188 mm and the max deformation value of the pier pillar was 65 mm.The construction technology of the gateway retained along the goaf with the pier pillar backfilled with the high water material was simple.The compressive strength of the pier pillar was high and could control the deformation of the surrounding rock.Meanwhile,the ventilation cross section enlarged of the mine roadway would be favorable for the ventilation gas discharging and could prevent the gas accident occurred in the mine.%为了改善木垛沿空留巷木料消耗量大、劳动强度高、施工复杂、支护强度较低的问题,高河煤矿采用了高水材料充填墩柱沿空留巷技术,并在E1302回风巷进行了工业性试验。结果表明:木垛沿空留巷顶底板最大移近量为286 mm,采用高水材料充填墩柱沿空留巷技术顶底板最大移近量为188 mm,墩柱最大变形量为65 mm,高水材料充填墩柱沿空留巷技术施工工艺简单、墩柱抗压强度大,可有效控制围岩变形,同时增大巷道通风断面有利于风排瓦斯,防止矿井发生瓦斯事故。

  19. 超高水材料覆岩离层及冒落裂隙带注浆充填技术%Grouting Backfill Technology with Super High Water Material for Overburden Bed-separation and Falling Fractured Zone

    Institute of Scientific and Technical Information of China (English)

    王成真; 冯光明

    2011-01-01

    In order to the problems occurred by the great amount pressurized flowing water in the bed-separation after the traditional grouting and subsidence control technology conducted in the overburden bed-separation, in combination with the basic performances of the super water material, based on the key strata theory of the strata control as the guide, the grouting backfill technology with the super water material was provided for the overburden strata bed-separation and falling fractured zone.The technology would fully fill with the super water material in the bed-separation space, the space between the falling rocks of the falling zone and the cracks of the fractured zone.After the grouting material solidified, the filled material could control the activities of the overburden strata.The previous practical results of the overburden strata grouting and the application of the grouting and backfill technology to an imaginary coal mining face showed that the grouting and backfill with the super water material in the overburden strata bed-separation and falling fractured zone would have a subsidence reduction rate between 80% ~ 90% and would have a high production and high efficient coal mining in seam under the buildings,railway line and water body.%为了解决传统覆岩离层注浆减沉技术实施后离层区内大量承压可流动水体所带来的问题,结合超高水材料基本性能,以岩层控制的关键层理论为指导,提出了超高水材料覆岩离层及冒落裂隙带注浆充填技术.该技术将超高水材料浆液充满关键层下的离层空间、冒落带垮落矸石间缝隙以及裂缝带裂隙,凝固后的充填体控制上覆岩活动.根据以往覆岩离层注浆实践结果及超高水材料注浆充填技术在假想工作面的应用可知:超高水材料覆岩离层及冒落裂隙带注浆充填的减沉率在80%~90%,有助实现"三下"压煤开采的高产高效.

  20. Experimental Study on Optimization of Phosphogypsum Plaster Mix Proportion for Backfill Strength%磷石膏膏体充填材料强度优化配比试验研究

    Institute of Scientific and Technical Information of China (English)

    张小瑞; 赵国彦; 李地元; 孙智慧

    2015-01-01

    为研究贵州开磷矿业总公司采用磷石膏和黄磷渣胶结充填采空区的可行性,在实验室测试了磷石膏及黄磷渣的主要物理化学性质,制备了不同浓度不同配比的充填料浆,并测试其坍落度、泌水率和不同龄期的单轴抗压强度。采用正交试验设计优化磷石膏膏体配比,并采用Mathematica对强度数据进行拟合,得出本次试验的最优结果为:磷石膏膏体充填料的最优质量比为黄磷渣∶磷石膏=1∶4,添加CaO质量为5%,磷石膏膏体质量浓度为67%~68%。在该配比条件下,磷石膏膏体充填体28 d单轴抗压强度为2.15~3.42 MPa,可满足矿山安全生产需求,并显著降低料浆泌水率。%In order to probe into the feasibility of backfilling the mined⁃out area with cemented mixture of phosphogypsum and yellow phosphorus slag for Guizhou Kaiyang Phosphorous Mine Bureau, backfill material with different slurry concentration and different proportioning were prepared based on the laboratory tests on the physical and mechanical properties of phosphogypsum and yellow phosphorus slag, for which the slump, bleeding rate and uniaxial compressive strength were also tested. Afterwards, orthogonal regression method was adopted to optimize the proportion of phosphogypsum plaster in the design and Mathematica was then used for strength data fit, leading to the optimized proportions of phosphogypsum plaster as backfill material as follows: the ratio of yellow phosphorus slag to phosphogypsum at 1∶4, addition of CaO in quantities of 5%, mass concentration of phosphogypsum plaster at 67%~68%. With such proportioning, the phosphogypsum plaster has a uniaxial compressive strength of 2.15~3.42 MPa after 28 days of aging with bleeding rate notably reduced, which can meet the safety requirement for mining production.

  1. Soil Solution

    NARCIS (Netherlands)

    Sonneveld, C.; Voogt, W.

    2009-01-01

    The characteristics of the soil solution in the root environment in the greenhouse industry differ much from those for field grown crops. This is caused firstly by the growing conditions in the greenhouse, which strongly differ from those in the field and secondly the function attributed to the soil

  2. Linking soil biodiversity and agricultural soil management

    NARCIS (Netherlands)

    Thiele-Bruhn, S.; Bloem, J.; Vries, de F.T.; Kalbitz, K.; Wagg, C.

    2012-01-01

    Soil biodiversity vastly exceeds aboveground biodiversity, and is prerequisite for ecosystem stability and services. This review presents recent findings in soil biodiversity research focused on interrelations with agricultural soil management. Richness and community structure of soil biota depend o

  3. Explore the Problems of Municipal Water Supply Pipeline Trench Excavation and Backfill%市政给水管道沟槽开挖及回填问题的研究

    Institute of Scientific and Technical Information of China (English)

    覃永和

    2014-01-01

    随着城市化进程的加快,城市给水管网改造工程也在不断的增多。本文主要就市政给水管网改造工程中的给水管道沟槽开挖及回填问题进行了研究,以提高给水管网改造工程的质量。%With the speeding up of urbanization, the reconstr-uction project of urban water supply pipeline network has in-creased. This article mainly carries on the exploration of the water supply pipe trench excavation and backfil problems in the municipal water supply pipeline network reconstruction en-gineering, in order to improve the quality of the water supply pipe network project.

  4. Environmental assessment of the reuse of municipal solid waste incineration bottom ash in quarry backfilling; Evaluation environnementale de la valorisation de machefers d'incineration d'ordures menageres en remplissage de carriere

    Energy Technology Data Exchange (ETDEWEB)

    Brons-Laot, G.

    2002-10-15

    The leaching behaviour of three different MSWI bottom ashes-based materials containing hydraulic binders is assessed in the conditions specified by the quarry backfilling application. An adapted approach methodology is applied: - physical, mineralogical and chemical characterizations of materials, - use of parametric tests to determine the effect of main scenarios factors on the release, - chemical modelling based on mineralogical and experimental leaching data with geochemical calculation codes, - chemical reaction / transport coupled modelling. The main results demonstrate that: - the batch and dynamic tests allow to obtain enough data to model and to predict the long term behaviour, - the chemical modelling of the solid / liquid equilibrium permits the determination of the chemical reactions involved and the prediction of pollutants solubilization in different chemical contexts, - the new materials (source term) present a low environmental impact in the conditions specified by the considered scenarios. (author)

  5. Development of On-line Monitoring System of Paste Backfill in the Goaf%采空区膏状充填体在线监测系统研制

    Institute of Scientific and Technical Information of China (English)

    张新国; 江宁; 江霞; 江兴元

    2011-01-01

    Gangue gream-body filling is the main technological means of realizing green mine and the best technology to solve the problem of mine under water body, building and rail, and on karst water body and to control surface subsidence, which used the surface movement observation to evaluate the filling effect in the past,but cycle is often longer,cost is higher and amount of labour is larger using the mood of surface movement observation. To this point, developed the on-line monitoring system of paste backfill in the goaf, based on the KJ216 monitoring system of plank pressure. Comprehensively evaluated the filling effect through long-term monitoring of long-term stress, deformation and hydration degree of paste backfill in the goaf. The practice showed that the system worked well on site.%作为实现“绿色开采”的主要技术手段和当前解决“三下一上”压煤问题,控制地表沉陷效果最好的矸石膏体充填开采技术,其充填效果评价过去一直采用的是地表岩移观测的方式,但是采用地表岩移观测的方式周期往往较长、费用较高、劳动量大.为此,基于K(J216顶板压力在线监测系统,研制了采空区膏状充填体在线监测系统.对采空区膏状充填体长期受力、变形和水化程度进行长期监测,综合评价充填效果.实践证明该系统现场应用效果良好.

  6. Study on Roadway Reinforcement Technique by Retractable Circular Support and Backfilling Grouting%可缩性圆形支架壁后充填注浆加固技术研究

    Institute of Scientific and Technical Information of China (English)

    李书民; 孙小岩; 张丰

    2011-01-01

    By analyzing the failure of traditional support by 36 U-shaped steel and wire mesh in the track dip in Changcun coal mine, it can be concluded that anchoring property is the primary cause for the low anchorage force and the poor effect of anchoring. Through analyzing the cross section of roadway and roadway reinforcement theory by backfilling grouting, roadway reinforcement technique by retractable circular support and backfilling grouting is put into effect This industrial practice demonstrates that this technique can solve the matter of deformation failure of soft rock roadway and can be used in other roadways with the similar situation in Changcun coal mine.%通过对常村煤矿轨道下山采用锚网(索)+ 36U型钢等常规支护形式失败的原因进行分析,得出巷道可锚性差是造成锚杆锚固力低和锚固效果差的主要因素;同时对巷道断面的选择和壁后充填注浆加固机理的分析,提出采用可缩性圆形支架壁后充填注浆加固技术.实践证明,采用可缩性圆形支架壁后充填注浆加固技术可有效解决软岩巷道变形的难题,为常村煤矿类似的巷道提供了一个有效的支护新途径.

  7. Life cycle performances of log wood applied for soil bioengineering constructions

    Science.gov (United States)

    Kalny, Gerda; Strauss-Sieberth, Alexandra; Strauss, Alfred; Rauch, Hans Peter

    2016-04-01

    Nowadays there is a high demand on engineering solutions considering not only technical aspects but also ecological and aesthetic values. Soil bioengineering is a construction technique that uses biological components for hydraulic and civil engineering solutions. Soil bioengineering solutions are based on the application of living plants and other auxiliary materials including among others log wood. This kind of construction material supports the soil bioengineering system as long as the plants as living construction material overtake the stability function. Therefore it is important to know about the durability and the degradation process of the wooden logs to retain the integral performance of a soil bio engineering system. These aspects will be considered within the framework of the interdisciplinary research project „ELWIRA Plants, wood, steel and concrete - life cycle performances as construction materials". Therefore field investigations on soil bioengineering construction material, specifically European Larch wood logs, of different soil bioengineering structures at the river Wien have been conducted. The drilling resistance as a parameter for particular material characteristics of selected logs was measured and analysed. The drilling resistance was measured with a Rinntech Resistograph instrument at different positions of the wooden logs, all surrounded with three different backfills: Fully surrounded with air, with earth contact on one side and near the water surface in wet-dry conditions. The age of the used logs ranges from one year old up to 20 year old. Results show progress of the drilling resistance throughout the whole cross section as an indicator to assess soil bioengineering construction material. Logs surrounded by air showed a higher drilling resistance than logs with earth contact and the ones exposed to wet-dry conditions. Hence the functional capability of wooden logs were analysed and discussed in terms of different levels of degradation

  8. Experimental study on back filling and rolling compaction of coarse-grained salty soil%粗颗粒盐渍土回填碾压试验研究

    Institute of Scientific and Technical Information of China (English)

    刘志伟; 程东幸; 张希宏

    2012-01-01

    在新疆大规模的开发建设中,大量的工程场地将遇到粗颗粒盐渍土。因厂址区附近建筑材料缺乏,外运距离远,场地回填及地基换填料同时成为工程面临的难题。本文遵循就地取材的原则,开展了粗颗粒盐渍土现场回填碾压试验和专题研究,确定了粗颗粒盐渍土作为回填料的适宜性及相关设计施工参数。试验研究表明:当粗颗粒盐渍土易溶盐含量不是很高,具轻微溶陷性,并不考虑盐胀时,场地料重新回填可消除原有的溶陷性,且地基承载力可达170kPa,通过级配改良,混合料回填碾压后地基承载力可达300kPa,有了较大提高。其成果的获得,具有明显的工程效益。%In the large-scale development and construction in Xinjiang Uygur Autonomous Region, the most engineering site will encounter the coarse-grained salty soil. Due to the lack of building materials near the site and the long-distance transport, the materials for the back filling and soil replacement are facing the engineering problems. Following the principle to obtain raw material locally, the backfill compaction tests with coarse-grained salty soil and the special study in the field are carried out, and the suitability of the coarse-grained salty soil as backfill material and the relative design and construction parameters are determined. When the easy resolving salt content in coarse-grained salty soil is not very high, and with slight thaw collapsibility, without considering the expansion of salts, the experimental study shows that the thaw collapsibility has been eliminated after the back filling and rolling compaction with the site soil, and the bearing capacity can reach 170kPa. Through improving the gradation, the strength of the compacted backfill has been greatly improved; the bearing capacity of the mixed material can reach 300kPa, which obtain the favorable engineering benefit.

  9. Soil Survey Geographic (SSURGO) - Magnesic Soils

    Data.gov (United States)

    California Department of Resources — Magnesic soils is a subset of the SSURGO dataset containing soil family selected based on the magnesic content and serpentinite parent material. The following soil...

  10. Schoolground Soil Studies.

    Science.gov (United States)

    Doyle, Charles

    1978-01-01

    Outlined are simple activities for studying soil, which can be conducted in the schoolyard. Concepts include soil profiles, topsoil, soil sizes, making soil, erosion, slope, and water absorption. (SJL)

  11. Test and Analysis on Soil Characteristics for the South Main Dyke of Jingjiang River%荆南长江干堤土性试验研究及分析

    Institute of Scientific and Technical Information of China (English)

    周小文; 何晓民; 龚壁卫

    2002-01-01

    In coordination of the construction of concealed work of levee project, the research on the soil quality of Jingnan levee in Hubei province was carried out through test. The results demonstrate: ① the Jingnan levee embankment is in bad quality, the compaction degree of most levee sections doesn't reach 92%; the average compressive coefficient of the levee backfilled soils is about 0.3 MPa; the seepage coefficients are 10\\+-5~10\\+-6 cm/s generally; the levee body was compacted unevenly; ② the soil layers of the levee foundation are distributed complicatedly and generally in low density; the void ratios of various soils are mostly in 0.7~1, indicating that the foundation soils are generally in loose state; ③ the pH value of levee body and foundation is 7.05~8.95, attributing to weak alkaline and not producing significant influence on liquid-plastic limit and shear strength of soils, the content of strongly soluble salt of levee foundation soils is 0.01%~0.52% and will not produce great influence on the mechanical behaviours of soils.

  12. 平移变位模式下黏性土非极限主动土压力%Non-limit active earth pressure of cohesive backfill under translation mode

    Institute of Scientific and Technical Information of China (English)

    陈奕柏; 柯才桐; 曹雄; 高洪波

    2014-01-01

    针对经典朗肯与库仑土压力理论不能计算非极限土压力的事实。根据土体渐进破坏机理,结合已有文献对准主动状态下土体摩擦角、黏聚力发挥值与墙体位移关系的研究,采用水平层分析法,通过建立水平微元体基本受力平衡方程,推导出非极限状态下黏性土主动土压力分布的一阶微分方程式。在此基础上给出了土压力合力及其作用点位置计算式,相应简化条件下,所提公式能够简化为朗肯、库仑主动土压力公式。算例分析结果表明:理论计算值与实测值基本吻合,获得了平移变位模式下黏性土非极限土压力随位移变化的规律,对实际工程挡土墙的设计计算具有一定的参考价值。%The classic Rankine and Coulomb earth pressure theory can not be used to calculate the non-limit earth pressure.Based on the progressive rupture mechanism,and combined with the existing research on the relationships between the mobilized friction angle,cohesion force and the displacement of rigid retaining wall under inter-mediate active state,the horizontal slices analysis method is used to de-duce the first-order differential equations of the active earth pressure distribution of cohesive backfill un-der unlimited state by establishing the basic force equilibrium equations of horizontal element.Based on this,the formula of the earth pressure resultant force and its action point are given,which can be simpli-fied to Rankine’s and Coulomb’s earth pressure formula under corresponding simplified conditions.The result of example analysis show that the calculated and measured earth pressure match with each other, the change regulation of non-limit earth pressure of cohesive backfill under translation mode is obtained, and which can be used for the design of retaining wall in practical engineering.

  13. 全尾砂胶结充填作用机理实验及数值模拟研究%Experimental and numerical simulative study on mechanism for cemented backfill of unclassified tailings

    Institute of Scientific and Technical Information of China (English)

    吴姗; 王东旭; 郭利杰

    2014-01-01

    采用钢筒实验,得到了岩柱被不同配比的全尾砂胶结充填料包围受压时的强度特征曲线,根据曲线特征将受压过程分为了三个阶段,充填体配比为1∶6时,其单轴抗压强度增大了42.9%,表明充填体与围岩共同作用,可显著提高岩柱的抗压强度。以某铁矿采用充填法开采为例,采用FLAC数值模拟,当空场在充填30%~65%时,空场底板应力及矿柱的竖向应力集中区域均变小,充填体施压于围岩,对围岩起柔性支护的作用。研究结果表明,充填体对围岩的支护类型为被动支护,可有效限制围岩继续变形作用,使采场处于稳定状态。%With steel tube experiments ,compressive strength characteristic curves of rock pillars surrounded by different proportions of unclassified tailings backfill material were obtained ,which divided compression process into three stages .As filling body ratio of 1 ∶ 6 ,the uniaxial compressive strength increased by 42 .9% ,indicating that filling body and rock together ,can significantly increase the compressive strength of rock pillar .To one Iron Mine used to fill mining method example ,through the FLAC numerical simulation ,when the empty field in filling 30% to 65% ,stresses of empty field plate and the vertical stress concentration areas of pillar are smaller ,and backfill pressure on surrounding rock which could flexible supporting the surrounding rock .The results show that the type of supporting filling body is passive support ,which can effectively limit the continued deformation of surrounding rock and make stope at a stable state .

  14. Biofuel or excavation? - Life cycle assessment (LCA) of soil remediation options

    Energy Technology Data Exchange (ETDEWEB)

    Suer, Pascal; Andersson-Skoeld, Yvonne [Swedish Geotechnical Institute, 58193 Linkoeping (Sweden)

    2011-02-15

    The environmental consequences of soil remediation through biofuel or through dig-and-dump were compared using life cycle assessment (LCA). Willow (Salix viminalis) was actually grown in-situ on a discontinued oil depot, as a phytoremediation treatment. These data were used for the biofuel remediation, while excavation-and-refill data were estimated from experience. The biofuel remediation had great environmental advantages compared to the ex situ excavation remediation. With the ReCiPe impact assessment method, which included biodiversity, the net environmental effect was even positive, in spite of the fact that the wood harvest was not utilised for biofuel production, but left on the contaminated site. Impact from the Salix viminalis cultivation was mainly through land use for the short rotation coppice, and through journeys of control personnel. The latter may be reduced when familiarity with biofuel as a soil treatment method increases. The excavation-and-refill remediation was dominated by the landfill and the transport of contaminated soil and backfill. (author)

  15. 风积砂质高浓度胶凝充填材料性能与粉煤灰掺量关系分析%RELATIONSHIP BETWEEN ENGINEERING PERFORMANCE AND MIX PROPORTION OF FLY ASH FOR CEMENTED AND HIGH CONCENTRATION BACKFILL MATERIAL WITH WIND-BLOWN SAND AS AGGREGATE

    Institute of Scientific and Technical Information of China (English)

    王晓东

    2016-01-01

    In coal mining with backfill,backfill material dominates the benefit,efficiency and effect.In order to get the characteristics varying pattern of cemented and high concentration backfill material with wind-blown sand as aggregate,fly ash is selected as variables to test and analyze the characteristics varying pattern of backfill material with the mix proportion of fly ash.The results show that,as the mix proportion of fly ash increases in a proper range in backfill material,the compressive strength increases,the bleeding rate decreases in general,the layered degree declines by linear pattern,the coagulation time grows up by exponential pattern,and the slump is growing consecutively.But,with the higher mix proportion of fly ash,the compressive strength and slump will drop comparatively.When the mix proportion of fly ash is in proper range,the fly ash optimizes the particle size gradient of backfill material,and makes water and cement distribution uniform in backfill material.As a result,the strength characteristic and rheological performance can be improved.However,some characteristics will degenerate with higher mix proportion of fly ash.%充填材料是决定煤炭充填开采效益、效率、效果的最主要因素.为了掌握风积砂质高浓度胶凝充填材料的性能变化规律,本文以粉煤灰的质量掺入比作为变量,试验研究和理论分析了粉煤灰对该充填材料性能的影响规律.结果表明,粉煤灰的适量添加可以提高充填材料的强度,大掺量导致强度相对降低;泌水率随着粉煤灰掺量的增大总体上呈减小趋势,较大掺量试样泌水速率相对较低;分层度随着粉煤灰掺量的增大线性降低;凝结时间随着粉煤灰掺量增大呈现指数增大;坍落度总体上随粉煤灰掺量的升高而增大,但大掺量会使其出现相对降低.分析认为,适量粉煤灰的掺入,使风积砂质高浓度胶凝充填材料的颗粒粒度、水分分布和水泥分散均匀,而使材

  16. Soil use and management

    NARCIS (Netherlands)

    Hartemink, A.E.; McBratney, A.B.; White, R.E.

    2009-01-01

    This four-volume set, edited by leading experts in soil science, brings together in one collection a series of papers that have been fundamental to the development of soil science as a defined discipline. Volume 3 on Soil Use and Management covers: - Soil evaluation and land use planning - Soil and

  17. Indicators: Soil Chemistry

    Science.gov (United States)

    The chemical makeup of the soil can provide information on wetland condition, wetland water quality and services being provided by the wetland ecosystem. Analyzing soil chemistry reveals if the soil is contaminated with a toxic chemical or heavy metal.

  18. Detailed Soils 24K

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set is a digital soil survey and is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The information was...

  19. Soil Organic Carbon Stock

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Soil organic carbon (SOC) is the carbon held within soil organic constituents (i.e., products produced as dead plants and animals decompose and the soil microbial...

  20. GeologicSoils_SOAG

    Data.gov (United States)

    Vermont Center for Geographic Information — GeologicSoils_SOAG includes a pre-selected subset of SSURGO soil data depicting prime agricultural soils in Vermont. The SSURGO county coverages were joined to the...

  1. Study on the Comprehensive Technology of Presupporting of Roof and Walls in Tailings Back-fill Mining%尾砂充填采矿法采场预控顶护帮综合技术研究

    Institute of Scientific and Technical Information of China (English)

    毛市龙; 杨鹏; 蔡嗣经; 赵海云

    2001-01-01

    To increase the mining capacity of Hedong Gold Mine,study was made on a new mining method at the mine,that was tailings back-fill mining with roof presupporting and sublevel open stoping.The new method adopted roof presupporting,deep and medium hole blasting,LHD ore removal and tailings filling.One-time blasting of deep and medium holes was applied for the cut-through raise and smooth surface blasting was used for the stope periphery and upper wall to ensure the stope safety.To ensure a smooth test,comprehensive technical measures for roof and wall supporting were taken.%为提高河东金矿的采矿生产能力,我们在河东金矿进行了新的采矿方法——预控顶分段空场尾砂充填采矿方法的研究。该采矿方法采用采场预控顶技术,中深孔爆破,铲运机出矿,尾砂充填。采场切割井用中深孔一次爆破技术,采场周边及上盘则采用光面爆破技术,确保采场稳定。为确保试验顺利进行,在采场进行了综合的护顶和护帮技术措施。

  2. Preparation of Whole-tailings Paste Backfilling Material with High Steel Slag Content and None Clinker Aggregate%高掺量钢渣无熟料体系制备全尾砂胶结充填料

    Institute of Scientific and Technical Information of China (English)

    胡文; 倪文; 张静文

    2012-01-01

    Using steel slag and tailings as the main filling material,this paper determined the optimized ingredient of the backfilling materials by analyzing the strength characteristics and mortar fluidity. X-ray diffraction analysis ( XRD) and scanning electron microscopy ( SEM) were used to observe microstructure and hydration products. The experiments result indicated that mortar fluidity can of artesian cemented filling and the 28 d compressive strength is 3. 73 MPa which can satisfy the requirement of compressive strength for mine filling when the content of steel slag, desulphogypsum, and slag is 63%,12%,and 25%.%以钢渣和尾砂为主要充填材料,综合分析料浆流动性能和胶结充填体强度,确定胶结充填料的优化配比,并通过X射线衍射(XRD)和扫描电镜(SEM)微观分析观察其微观结构和水化产物.试验结果表明,当钢渣掺量为63%、脱硫石膏掺量为12%、矿渣掺量为25%时,料浆流动性能满足自流型胶结充填的流动性要求,充填体28 d抗压强度为3.73 MPa,满足矿山充填强度要求.

  3. 强夯+CFG桩复合地基在较厚回填土中的应用%Application of dynamic compaction and CFG pile composite foundation in the treatment of thick backfill

    Institute of Scientific and Technical Information of China (English)

    郑宇; 王天勇; 杨铮; 金灿国; 王建华; 张相勇; 董素芹

    2013-01-01

    The design and construction method of dynamic compaction plus cement fly-ash grave ( CFG) pile were introduced to enhance the bearing capacity of foundation and control foundation settlement in thick backfill by an engineering example. The standard penetration test and static loading test were carried out to topsoil compacted by dynamic compaction, and the bearing capacity of the composite foundation processed by dynamic compaction and CFG was detected by static loading test of single pile composite foundation and vertical compression static loading test of single pile. The results show that the bearing capacity and deformation of composite foundation are acceptable and can meet the requirement of related codes. Moreover, the engineering example shows this method can shorten the construction period and is economic, convenient and safe.%通过工程实例,介绍了在较厚回填土中采用强夯+ CFG桩复合地基进行地基处理以提高地基承载力及控制沉降的设计及施工方法.强夯后对表层土进行标准贯入试验及静力载荷试验,打入CFG桩后对复合地基承载力进行单桩复合地基静载荷试验与单桩竖向抗压静载荷试验检测,结果表明地基承载力与变形均满足规范要求.工程实例表明采用此方法可节约造价、缩短工期且安全可靠.

  4. 薄煤层泵送矸石充填开采矿压显现规律研究%Research on Strata Behavior in the Process of Gangue Backfill by Filling Pump in Thin Coal Seam

    Institute of Scientific and Technical Information of China (English)

    林惠立; 李洪; 刘庆龙

    2012-01-01

    为有力地配合北宿煤矿薄煤层泵送矸石充填开采工业性试验,更好的为今后薄煤层充填开采提供可靠依据,在C1661充填开采工作面进行了矿压观测,C1661充填开采工作面与1863采用全部垮落法开采工作面相比,顶底板移近量增大11.4%,单体支柱末阻力增大54.8%,液压切顶支架末阻力增加8.8%,支架活柱缩量增大5.7%,支护强度基本相等,来压强度减小28%,周期来压步距增大27.3%,初次来压步距增大12%。%In order to coordinate with industrial test of gangue backfill by filling pump in thin coal seam in Beisu Coal Mine, and provide a more reliable basis for fill mining in thin coal seam in the future, strata control observation was conducted in C1661 working face. And com- pared with 1863 face which was mined by caving method, convergence between roof and floor increased by 11.4%, terminal resistance of sin- gle prop increased by 54.8%, terminal resistance of hydraulic support increased by 8.8%, expansion amount of hydraulic support increased by 5.7%, ground pressure strength decreased by 5.7%, periodic weighting length increased by 27.3%, first weighting interval increased by 12%, and the strength of support was basically the same.

  5. Soils, Soils, Published in 2004, Taylor County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Soils dataset, was produced all or in part from Published Reports/Deeds information as of 2004. It is described as 'Soils'. Data by this publisher are often...

  6. Surfactant adsorption to soil components and soils

    NARCIS (Netherlands)

    Ishiguro, Munehide; Koopal, Luuk K.

    2016-01-01

    Soils are complex and widely varying mixtures of organic matter and inorganic materials; adsorption of surfactants to soils is therefore related to the soil composition. We first discuss the properties of surfactants, including the critical micelle concentration (CMC) and surfactant adsorption on

  7. Soil-structure interaction including nonlinear soil

    OpenAIRE

    Gicev, Vlado

    2008-01-01

    There are two types of models of soil-structure system depending upon the rigidity of foundation: models with rigid and models with flexible foundation. Main features of the soil-structure interaction phenomenon: -wave scattering, -radiation damping, -reduction of the system frequencies. In this presentation, the influence of interaction on the development of nonlinear zones in the soil is studied.

  8. NOrth AMerica Soil (NOAM-SOIL) Database

    Science.gov (United States)

    Miller, D. A.; Waltman, S. W.; Geng, X.; James, D.; Hernandez, L.

    2009-05-01

    NOAM-SOIL is being created by combining the CONUS-SOIL database with pedon data and soil geographic data coverages from Canada and Mexico. Completion of the in-progress NOrth AMerica Soil (NOAM-SOIL) database will provide complete North America coverage comparable to CONUS. Canadian pedons, which number more than 500, have been painstakingly transcribed to a common format, from hardcopy, and key- entered. These data, along with map unit polygons from the 1:1,000,000 Soil Landscapes of Canada, will be used to create the required spatial data coverages. The Mexico data utilizes the INEGI 1:1,000,000 scale soil map that was digitized by U. S. Geological Survey EROS Data Center in the mid 1990's plus about 20,000 pedons. The pedon data were published on the reverse side of the paper 1:250,000 scale Soil Map of Mexico and key entered by USDA and georeferenced by Penn State to develop an attribute database that can be linked to the 1:1,000,000 scale Soil Map of Mexico based on taxonomic information and geographic proximity. The essential properties that will be included in the NOAM-SOIL data base are: layer thickness (depth to bedrock or reported soil depth); available water capacity; sand, silt, clay; rock fragment volume; and bulk density. For quality assurance purposes, Canadian and Mexican soil scientists will provide peer review of the work. The NOAM-SOIL project will provide a standard reference dataset of soil properties for use at 1km resolution by NACP modelers for all of North America. All data resources, including metadata and selected raw data, will be provided through the Penn State web site: Soil Information for Environmental Modeling and Ecosystem Management (www.soilinfo.psu.edu). Progress on database completion is reported.

  9. Fundamentals of soil science

    Science.gov (United States)

    This study guide provides comments and references for professional soil scientists who are studying for the soil science fundamentals exam needed as the first step for certification. The performance objectives were determined by the Soil Science Society of America's Council of Soil Science Examiners...

  10. Hot fire, cool soil

    NARCIS (Netherlands)

    Stoof, C.R.; Moore, D.; Fernandes, P.; Stoorvogel, J.J.; Fernandes, R.; Ferreira, A.J.D.; Ritsema, C.J.

    2013-01-01

    Wildfires greatly increase a landscape's vulnerability to flooding and erosion events by removing vegetation and changing soils. Fire damage to soil increases with increasing soil temperature, and, for fires where smoldering combustion is absent, the current understanding is that soil temperatures i

  11. Restoring Soil Quality to Mitigate Soil Degradation

    Directory of Open Access Journals (Sweden)

    Rattan Lal

    2015-05-01

    Full Text Available Feeding the world population, 7.3 billion in 2015 and projected to increase to 9.5 billion by 2050, necessitates an increase in agricultural production of ~70% between 2005 and 2050. Soil degradation, characterized by decline in quality and decrease in ecosystem goods and services, is a major constraint to achieving the required increase in agricultural production. Soil is a non-renewable resource on human time scales with its vulnerability to degradation depending on complex interactions between processes, factors and causes occurring at a range of spatial and temporal scales. Among the major soil degradation processes are accelerated erosion, depletion of the soil organic carbon (SOC pool and loss in biodiversity, loss of soil fertility and elemental imbalance, acidification and salinization. Soil degradation trends can be reversed by conversion to a restorative land use and adoption of recommended management practices. The strategy is to minimize soil erosion, create positive SOC and N budgets, enhance activity and species diversity of soil biota (micro, meso, and macro, and improve structural stability and pore geometry. Improving soil quality (i.e., increasing SOC pool, improving soil structure, enhancing soil fertility can reduce risks of soil degradation (physical, chemical, biological and ecological while improving the environment. Increasing the SOC pool to above the critical level (10 to 15 g/kg is essential to set-in-motion the restorative trends. Site-specific techniques of restoring soil quality include conservation agriculture, integrated nutrient management, continuous vegetative cover such as residue mulch and cover cropping, and controlled grazing at appropriate stocking rates. The strategy is to produce “more from less” by reducing losses and increasing soil, water, and nutrient use efficiency.

  12. Soil thermal resistivity and thermal stability measuring instrument. Volume 2: Manual for operation and use of the thermal property analyzer and statistical weather analysis program to determine thermal design parameters

    Science.gov (United States)

    Boggs, S. A.; Radhakrishna, H. S.; Chu, F. Y.; Ford, G. L.; Griffin, J. D. A.; Steinmanis, J.

    1981-11-01

    Numerous considerations influence the thermal design of an underground power cable, including the soil thermal resistivity, thermal diffusivity and thermal stability. Each of these properties is a function of soil moisture which is in turn a function of past weather, soil composition, and biological burden. The Neher-McGrath formalism has been widely used for thermal cable design. However, this formalism assumes knowledge of soil thermal properties (resistivity and diffusivity). For design purposes, these parameters should be treated statistically, since weather varies greatly from year to year. As well, soil thermal property surveys are normally required along the route to assess the thermal quality of the native soil. This project is intended to fill the gap between the need to carry out thermal design and the use of the Neher-McGrath formalism which is normally employed. This goal has been addressed through: development of instrumentation and methods of measuring soil thermal properties in situ and in the laboratory; recommendation of methods for conducting soil surveys along a proposed cable route and of assessing the thermal quality of soils; and development of a computerized method to treat soil thermal design parameters on a statistical basis using computerized weather records as supplied by the US Environmental Data Service. The use of the methods and instrumentation developed as a result of this contract should permit less conservative thermal design thereby improving the economics of underground transmission. As well, these techniques and instrumentation facilitate weather-dependent prediction of cable ampacity for installed cables, monitoring of backfill thermal stability, and many other new practices.

  13. Classification of Ferrallitic Soils in Chinese Soil Taxonomy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The development of the classification of ferrallitic soils in China is reviewed and the classification of Ferralisols and Ferrisols in Chinese Soil Taxonomy is introduced in order to discuss the correlation between the ferrallitic soil classification in the Chinese Soil Taxonomy and those of the other soil classification systems. In the former soil classification systems of China, the ferrallitic soils were classified into the soil groups of Latosols, Latosolic red soils, Red soils, Yellow soils and Dry red soils, according to the combination of soil forming conditions, soil-forming processes, soil features and soil properties. In the Chinese Soil Taxonomy, most of ferrallitic soils are classified into the soil orders of Ferralisols and Ferrisols based on the diagnostic horizons and/or diagnostic characteristics with quantitatively defined properties. Ferralisols are the soils that have ferralic horizon, and they are merely subdivided into one suborder and two soil groups. Ferrisols are the soils that have LAC-ferric horizon but do not have ferralic horizon, and they are subdivided into three suborders and eleven soil groups. Ferralisols may correspond to part of Latosols and Latosolic red soils. Ferrisols may either correspond to part of Red soils, Yellow soils and Dry red soils, or correspond to part of Latosols and Latosolic red soils.

  14. Cross-cutting activities: Soil quality and soil metagenomics

    OpenAIRE

    Peter P. Motavalli; Garrett, Karen A.

    2008-01-01

    This presentation reports on the work of the SANREM CRSP cross-cutting activities "Assessing and Managing Soil Quality for Sustainable Agricultural Systems" and "Soil Metagenomics to Construct Indicators of Soil Degradation." The introduction gives an overview of the extensiveness of soil degradation globally and defines soil quality. The objectives of the soil quality cross cutting activity are: CCRA-4 (Soil Metagenomics)

  15. Research on the Optimal Roof-contacted Filling Ratio of Upward Drift Stoping with Backfill%上向进路充填采矿法最佳充填接顶率研究

    Institute of Scientific and Technical Information of China (English)

    刘发平; 陈宪龙

    2015-01-01

    In the process of upward drift stoping with backfill in Baixiangshan iron mine,the roof-contacted effect is not perfect,the roof-contacted filling ratio of the mine is researched.The MIDAS /GTS finite element software is applied to analyze the stress condition of the first-step approach stope cemented pillars that have different roof-contacted filling ratio when the second-step approach stope are conducted. Besides that,the security and stability of the cemented pillars are evaluated,and the different roof-con-tacted filling ratios are analyzed in depth so as to determine the optimal roof-contacted filling ratio.when the second-step approach stope are conducted,the tensile safety coefficient of the first-step approach stope cemented pillars with 80%roof-contacted filling ratio is 2.03,the compressive strength factor of safety is 1.28,the synthesized safety coefficient is 1.60.The above research results can provide a brand-new di-rection for the other mines to improve the roof-contacted filling ratio scientifically.%为解决白象山铁矿在上向进路充填采矿过程中充填接顶效果不理想的问题,对该矿山的充填接顶率进行了研究。运用 MIDAS /GTS 有限元软件模拟分析二步进路采场开采时,一步进路采场不同充填接顶率胶结矿柱受力状况,并对胶结矿柱安全稳定性进行评价,对不同充填接顶率进行分析,从而确定最佳充填接顶率。当二步进路采场开采时,一步进路采场80%充填接顶率胶结矿柱抗拉安全系数为2.03,抗压安全系数为1.28,综合安全系数为1.6,为该矿上向进路充填法的最佳充填接顶率。该研究为其他矿山科学提高充填接顶率提供了一种全新的指导方向。

  16. Research on Backfilling Friction Stir Spot Welding of LY12 Al Alloy%LY12铝合金回填式搅拌摩擦点焊工艺研究

    Institute of Scientific and Technical Information of China (English)

    王朗; 王敏; 郭立杰

    2013-01-01

    采用回填式搅拌摩擦点焊对1mm厚的LY12铝合金薄板进行焊接,研究单参数对接头拉剪力的影响.结果表明,在其他条件不变时,套下压时间影响接头U型区域的宽度,套下压时间为3.2s时,接头的拉剪力达到最大值;其他参数对U型区域深度产生影响;回填时间为0.4s、旋转速度为1500r/min、下压深度为1.1mm、焊接压力为23 MPa时接头的拉剪力均达到最大值.正交试验工艺优化结果表明,最佳的工艺参数组合为:套下压时间为3.6s、回填时间为0.9s、旋转速度为2400r/min、下压深度为1.1mm、压力为24 MPa.对最佳参数组合下的接头进行金相分析,发现接头区域分为三个部分:混合区、热影响区和母材.%The backfilling friction stir spot welding to weld 1 mm-thick LY12 aluminum alloy plate was adopted, and the single parameter on the effect of joint's shear load was investigated. The results show that when other conditions remain unchange, pressure time affect the width of the joint area. When pressure time is 3.2 s, joint's shear load reach maximum; other parameters affect the depth of the joint area; when refilling time is 0.4 s, rotating speed is 1500 r/min, depth is 1.1 mm, pressure is 23MPa, joint's shear load reaches maximum. After the optimization of process parameters, the orthogonal test results show that the best process parameter combination is pressure time 3.6s, refilling time 0.9s, rotating speed 2400 r/m, depth 1.1 mm, pressure 24 MPa. The metallographic analysis of the welded joint at the best parameters found that the joint area is divided into three parts: mixed zone, heat affected zone and mother material.

  17. Erosion and deposition by supercritical density flows during channel avulsion and backfilling: Field examples from coarse-grained deepwater channel-levée complexes (Sandino Forearc Basin, southern Central America)

    Science.gov (United States)

    Lang, Jörg; Brandes, Christian; Winsemann, Jutta

    2017-03-01

    Erosion and deposition by supercritical density flows can strongly impact the facies distribution and architecture of submarine fans. Field examples from coarse-grained channel-levée complexes from the Sandino Forearc Basin (southern Central America) show that cyclic-step and antidune deposits represent common sedimentary facies of these depositional systems and relate to the different stages of avulsion, bypass, levée construction and channel backfilling. During channel avulsion, large-scale scour-fill complexes (18 to 29 m deep, 18 to 25 m wide, 60 to > 120 m long) were incised by supercritical density flows. The multi-storey infill of the large-scale scour-fill complexes comprises amalgamated massive, normally coarse-tail graded or widely spaced subhorizontally stratified conglomerates and pebbly sandstones, interpreted as deposits of the hydraulic-jump zone of cyclic steps. The large-scale scour-fill complexes can be distinguished from small-scale channel fills based on the preservation of a steep upper margin and a coarse-grained infill comprising mainly amalgamated hydraulic-jump zone deposits. Channel fills include repeated successions deposited by cyclic steps with superimposed antidunes. The deposits of the hydraulic-jump zone of cyclic steps comprise regularly spaced scours (0.2 to 2.6 m deep, 0.8 to 23 m long) infilled by intraclast-rich conglomerates or pebbly sandstones, displaying normal coarse-tail grading or backsets. These deposits are laterally and vertically associated with subhorizontally stratified, low-angle cross-stratified or sinusoidally stratified sandstones and pebbly sandstones, which were deposited by antidunes on the stoss side of the cyclic steps during flow re-acceleration. The field examples indicate that so-called spaced stratified deposits may commonly represent antidune deposits with varying stratification styles controlled by the aggradation rate, grain-size distribution and amalgamation. The deposits of small-scale cyclic

  18. 充填采煤面收作眼围岩变形控制技术研究%Study on surrounding rock deformation control of finishing cut in backfilling mining face

    Institute of Scientific and Technical Information of China (English)

    李猛; 张吉雄; 巨峰; 刘世伟; 曹远威

    2016-01-01

    To solve support dismantling problems caused by big cross-section finishing cut and to con-trol strata movement in solid backfilling mining face,this paper has adopted the theoretical analysis and FLAC3D numerical simulation method to study laws of surrounding rock deformation and failure mechanism of finishing cut. Then the comprehensive support technology of anchor (rope) mesh rein-forcement, temporary support of“#” type wooden cogs filled with grouting and permanent support of finishing cut grouting have been put forward. In addition,the supporting parameters of concrete pier consisting of wooden cogs has been optimized. The results have shown that when the reasonable spac-ing of concrete pier is 2 000 mm, the pier bearing capacity can satisfy the requirement of temporary support. The technology has been applied in Yangzhuang coal mine of Huaibei Coal Mining Group, and the accumulated sink value about 80 m above the working face has been only 60 mm, which has indi-cated that surrounding rock deformation control of finishing cut is well controlled.%为解决充填采煤面收作眼断面大、难支护及撤架困难等难题,采用理论分析和FLAC3D数值模拟方法研究了收作眼围岩变形破坏规律,提出了滑架通道锚(索)网加强支护、“井”字型木垛封闭灌浆的临时支护和收作眼空间注浆永久支护相结合的围岩控制技术方法,优化设计了“井”字型木垛形成的混凝土墩柱支护参数。结果表明:混凝土墩柱间排距均为2000 mm时,墩柱承载能力可满足临时支护的要求。该技术在淮北矿业集团杨庄煤矿进行了应用,通过监测工作面上方垂距约为80 m的巷道变形,其巷道累积下沉量仅为60 mm,表明收作眼围岩变形控制效果显著。

  19. Study on Soil Magnetic Effect

    Institute of Scientific and Technical Information of China (English)

    YIYAN-LI; LIUXIAO-YI

    1995-01-01

    A study on the effect of applied magnetic field was performed with six types of soils collected from northeastern China.Magnetic field was found to cause changes of soil physico-chemical properties and soil enzyme activities.An appropriate applied magnetic field could cut down soil zeta-potential,soil specific surface,soil water potential and soil swelling capacity;raise the charge density on soil colloids and the activities of invertase,hydrogen peroxidase and amylase in the soils;enhance soil aggregation and improve soil structural status and soil water-releasing capability.

  20. Soil depth map definition on a terraced slope for a following distributed, high resolution, numerical modelling analysis

    Science.gov (United States)

    Camera, C.; Apuani, T.; Mele, M.; Kuriakose, S. L.; Giudici, M.

    2012-04-01

    The soil thickness represents a key data for every environmental analysis involving soil, but its determination is not always simple. In this particular case, the study area is represented by a small terraced slope (0.6 km2) of Valtellina (Northern Italy), and the soil depth map is necessary for a coupled hydrogeological-stability analysis in a raster environment. During this work geometrical/morphological and geostatistical interpolation techniques were tested to obtain a satisfying soil depth map. At the end, the final product has been validated with geo-electrical resistivity inverse models. In this particular context, the presence of dry-stone retaining walls is of primary importance, since they have an influence on the morphology of the entire area as well as on the physical processes of water infiltration and slope stability. In order to consider the dry-stone walls in the analysis, it is necessary to have base maps with an adequate resolution (cells 1 m x 1 m). Assuming that the walls might be founded on bedrock or in its proximity, it was decided to use the heights of walls and the distribution of rock outcrops as soil depth input data. It was impossible to obtain direct measures with the knocking pole method, being pebbles frequently presents in the backfill soil . Except zero depth values, 682 measures were performed. The initial data set was divided into two subsets in order to use one as training points (76 % of the total) and the second as test points (24 %). Various techniques were tested, from linear multiple regressions with environmental predictors, to ordinary kriging, regression kriging with the same environmental variables, and Gaussian stochastic simulations. At the end, the best result was obtained with co-kriging, using a soil depth class map drawn from the field measures as co-variable. The result is a little bit guided but it was the only solution to obtain a map that partially takes into account the morphology of the slope. To verify the

  1. 考虑土拱效应的非垂直挡墙地震主动土压力%SEISMIC ACTIVE EARTH PRESSURE FOR NON-VERTICAL RIGID RETAINING WALL CONSIDERING SOIL ARCHING EFFECT

    Institute of Scientific and Technical Information of China (English)

    周亦涛; 陈福全

    2015-01-01

    The stresses on the wall and sliding plane of the sliding backfill mass at arbitrary depths were obtained according to the soil arching effect. A formula of the seismic active failure angle behind the non-vertical rigid retaining wall under translation mode was obtained on the basis of the pseudo-static method and the equilibrium total forces. A formula of the seismic active earth pressure against the non-vertical rigid retaining wall under translation mode was derived according to the method of differential level layer. The seismic active earth force and the action point were obtained. The distribution of seismic active earth pressure from the proposed formula was non-linear along the height of wall. In addition,the influences of the wall-back inclination,internal friction angle of backfill,wall-soil friction angle,seismic coefficient and load against the backfill surface on the seismic failure angle,seismic active earth pressure and its coefficient,seismic active earth force and height of its application were investigated.%由土拱效应原理得到滑裂土体的墙面和滑裂面上的应力,然后根据拟静力法和滑裂土体的整体受力平衡,得到平移模式下非垂直刚性挡土墙的地震主动破裂角计算式.进一步根据水平层分法获得墙背地震主动土压力及其系数、地震主动土压力合力及其作用点高度等的计算式.此外,分别讨论墙背倾角、填土内摩擦角、墙土摩擦角、地震系数和填土表面荷载等对地震主动破裂角、法向地震主动土压力分析、地震主动土压力合力系数、地震主动土压力合力及其作用点相对高度等的影响.

  2. GeologicSoils_ONSITE

    Data.gov (United States)

    Vermont Center for Geographic Information — ONSITE is a pre-selected subset of SSURGO certified soil data depicting onsite sewage disposal ratings of Vermont soils. The SSURGO county coverages were joined to...

  3. Soil and Litter Animals.

    Science.gov (United States)

    Lippert, George

    1991-01-01

    A lesson plan for soil study utilizes the Tullgren extraction method to illustrate biological concepts. It includes background information, equipment, collection techniques, activities, and references for identification guides about soil fauna. (MCO)

  4. iSOIL: Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping

    Science.gov (United States)

    Dietrich, Peter; Werban, Ulrike; Sauer, Uta

    2010-05-01

    High-resolution soil property maps are one major prerequisite for the specific protection of soil functions and restoration of degraded soils as well as sustainable land use, water and environmental management. To generate such maps the combination of digital soil mapping approaches and remote as well as proximal soil sensing techniques is most promising. However, a feasible and reliable combination of these technologies for the investigation of large areas (e.g. catchments and landscapes) and the assessment of soil degradation threats is missing. Furthermore, there is insufficient dissemination of knowledge on digital soil mapping and proximal soil sensing in the scientific community, to relevant authorities as well as prospective users. As one consequence there is inadequate standardization of techniques. At the poster we present the EU collaborative project iSOIL within the 7th framework program of the European Commission. iSOIL focuses on improving fast and reliable mapping methods of soil properties, soil functions and soil degradation risks. This requires the improvement and integration of advanced soil sampling approaches, geophysical and spectroscopic measuring techniques, as well as pedometric and pedophysical approaches. The focus of the iSOIL project is to develop new and to improve existing strategies and innovative methods for generating accurate, high resolution soil property maps. At the same time the developments will reduce costs compared to traditional soil mapping. ISOIL tackles the challenges by the integration of three major components: (i)high resolution, non-destructive geophysical (e.g. Electromagnetic Induction EMI; Ground Penetrating Radar, GPR; magnetics, seismics) and spectroscopic (e.g., Near Surface Infrared, NIR) methods, (ii)Concepts of Digital Soil Mapping (DSM) and pedometrics as well as (iii)optimized soil sampling with respect to profound soil scientific and (geo)statistical strategies. A special focus of iSOIL lies on the

  5. Factors affecting soil cohesion

    Science.gov (United States)

    Soil erodibility is a measure of a soil’s resistance against erosive forces and is affected by both intrinsic (or inherent) soil property and the extrinsic condition at the time erodibility measurement is made. Since soil erodibility is usually calculated from results obtained from erosion experimen...

  6. Conserving Soil. Revised.

    Science.gov (United States)

    Soil Conservation Service (USDA), Washington, DC.

    This book of enrichment materials is an interdisciplinary study of soil designed for students in grades 6-9. The materials are presented in three units. Unit 1 contains eight activities in which students investigate soil science and study the social impact of soil by examining the history of land use by local Native Americans. Unit 2 contains 10…

  7. Thermal Properties of Soils

    Science.gov (United States)

    1981-12-01

    plagio - clase feldspar and pyroxene. The tine fraction may Surface area and its effects contain the clay "sheet" minerals (i.e. kaolinite. illite...Pyroxene, Kaoliniwe Unified By By Ortho. Plagio . amphibole, Basic clay min. Hematite Soil Soil soil petrogr. X.ray clase clase and Igneous and clay and no

  8. Visual soil evaluation

    DEFF Research Database (Denmark)

    Visual Soil Evaluation (VSE) provides land users and environmental authorities with the tools to assess soil quality for crop performance. This book describes the assessment of the various structural conditions of soil, especially after quality degradation such as compaction, erosion or organic...

  9. Soil immune responses

    NARCIS (Netherlands)

    Raaijmakers, Jos M.; Mazzola, Mark

    2016-01-01

    Soil microorganisms are central to the provision of food, feed, fiber, and medicine. Engineering of soil microbiomes may promote plant growth and plant health, thus contributing to food security and agricultural sustainability (1, 2). However, little is known about most soil microorganisms and their

  10. Soil-water characteristics of sandy soil and soil cement with and without vegetation

    OpenAIRE

    2014-01-01

    The use of soil cement as a growth medium was examined in this study. During the monitoring, green soil cement revealed diverse ecological values. The survival rates of plants in each soil conditions were higher than 80%,which was very promising. Furthermore, the survival rates dropped when the soil density reached95%, which means soil density might influence the survival rate of plant. Plant growth rates in sandy soil were higher than that in soil cement. In particular, low soil density faci...

  11. 煤矿膏体充填材料性能随龄期变化的试验研究%Experimental study on the changes of coal paste backfilling material performance during hydration process

    Institute of Scientific and Technical Information of China (English)

    戚庭野; 冯国瑞; 郭育霞; 张玉江; 任昂; 康立勋; 郭军

    2015-01-01

    Coal paste backfilling material (CPBM) is composed of coal gangue, flyash, ordinary port-land cement and tap water. In order to identify the properties of each raw material, the mineral composi-tion, chemical composition of coal gangue flyash have been analyzed;the compressive strength, porosi-ty and electrical resistivity have been studied at different curing times. The samples taken from curing time of 7 d, 14 d and 28 d, have been evaluated for their mineral composition and microstructure. The law of CPBM property with increasing curing time has been analyzed, and the correlation among the compressive strength, porosity, resistivity and hydrating process has also been deeply discussed. The results indicate that firstly, with the curing time increasing, compressive strength and electrical resistiv-ity are increasing, while porosity and small pore content are reducing. Secondly, hydrated and poz-zolanic reaction occur in the change of CPBM property, with calcium hydroxide, C-S-H gel and ettring-ite being the reaction products. The calcium hydroxide crystal is only found at the curing time of 7 d, not at 14 d and 28 d, and the types and quantities of ettringite crystal at 28 d are more than at 7 d and 14 d. The crystal structure of 28 d presented more slender with the curing time increasing. Thirdly, the hy-drated and pozzolanic reaction are the two primary reasons causing the change of performance of CPBM strength with the change of curing time. Moreover,there is some interrelation between the per-formances.%煤矿膏体充填材料(CPBM)由煤矸石、粉煤灰、水泥和水为原料混合而成。为了了解各原料的性质,对煤矸石和粉煤灰的矿物组成、化学成分进行了分析,对固定配比CPBM在不同龄期的抗压强度、孔隙率和电阻率性能进行了研究,测定和观测7,14和28 d的矿物成分和微观结构;针对抗压强度、孔隙率、电阻率和水化过程之间存在的相关性进行了

  12. Corrosion of low-carbon steel under environmental conditions at Hanford: Two-year soil corrosion test results

    Energy Technology Data Exchange (ETDEWEB)

    Anantatmula, R.P. [Westinghouse Hanford Co., Richland, WA (United States); Divine, J.R. [ChemMet Ltd., West Richland, WA (United States)

    1995-11-01

    At the Hanford Site, located in southeastern Washington state, nuclear production reactors were operated from 1944 to 1970. The handling and processing of radioactive nuclear fuels produced a large volume of low-level nuclear wastes, chemical wastes, and a combination of the two (mixed wastes). These materials have historically been packaged in US Department of Transportation (DOT) approved drums made from low-carbon steel, then handled in one of three ways: (A) Before 1970, the drums were buried in the dry desert soil. It was assumed that chemical and radionuclide mobility would be low and that the isolated, government-owned site would provide sufficient protection for employees and the public. (B) After 1970, the drums containing long-lived transuranic radionuclides were protected from premature failure by stacking them in an ordered array on an asphalt concrete pad in the bottom of a burial trench. The array was then covered with a large, 0.28-mm- (011-in.-) thick polyethylene tarp and the trench was backfilled with 1.3 m (4 ft) of soil cover. This burial method is referred to as soil-shielded burial . Other configurations were also employed but the soil-shielded burial method contains most of the transuranic drums. (C) Since 1987, US Department of Energy sites have complied with the Resource Conservation and Recovery Act of 1976 (RCRA) regulations. These regulations require mixed waste drums to be stored in RCRA compliant large metal sheds with provisions for monitoring. These sheds are provided with forced ventilation but are not heated or cooled.

  13. Experimental unsaturated soil mechanics

    CERN Document Server

    Delage, Pierre

    2008-01-01

    In this general report, experimental systems and procedures of investigating the hydro-mechanical behaviour of unsaturated soils are presented. The water retention properties of unsaturated soils are commented and linked to various physical parameters and properties of the soils. Techniques of controlling suction are described together with their adaptation in various laboratory testing devices. Some typical features of the mechanical behaviour of unsaturated soils are presented within an elasto-plastic framework. An attempt to describe the numerous and significant recent advances in the investigation of the behaviour of unsaturated soils, including the contributions to this Conference, is proposed.

  14. Soil heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Sherameti, Irena [Jena Univ. (Germany). Inst. fuer Allgemeine Botanik und Pflanzenphysiologie; Varma, Ajit (eds.) [Amity Univ., Uttar Pradesh (India). Amity Inst. of Microbial Technology; Amity Science, Technology and Innovation Foundation, Noida, UP (India)

    2010-07-01

    Human activities have dramatically changed the composition and organisation of soils. Industrial and urban wastes, agricultural application and also mining activities resulted in an increased concentration of heavy metals in soils. How plants and soil microorganisms cope with this situation and the sophisticated techniques developed for survival in contaminated soils is discussed in this volume. The topics presented include: the general role of heavy metals in biological soil systems; the relation of inorganic and organic pollutions; heavy metal, salt tolerance and combined effects with salinity; effects on abuscular mycorrhizal and on saprophytic soil fungi; heavy metal resistance by streptomycetes; trace element determination of environmental samples; the use of microbiological communities as indicators; phytostabilization of lead polluted sites by native plants; effects of soil earthworms on removal of heavy metals and the remediation of heavy metal contaminated tropical land. (orig.)

  15. Tropical Soil Chemistry

    DEFF Research Database (Denmark)

    Borggaard, Ole K.

    and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors......A new book that is particularly relevant as tropical countries experience increased pressure on land resources to improve agricultural production. To ensure sustainable land use, the potentials and limitations of different kinds of tropical soils must be known in relation to crop production...... soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics...

  16. From soil in art towards Soil Art

    Science.gov (United States)

    Feller, C.; Landa, E. R.; Toland, A.; Wessolek, G.

    2015-02-01

    The range of art forms and genres dealing with soil is wide and diverse, spanning many centuries and artistic traditions, from prehistoric painting and ceramics to early Renaissance works in Western literature, poetry, paintings, and sculpture, to recent developments in cinema, architecture and contemporary art. Case studies focused on painting, installation, and cinema are presented with the view of encouraging further exploration of art about, in, with, or featuring soil or soil conservation issues, created by artists, and occasionally scientists, educators or collaborative efforts thereof.

  17. Mass Transport within Soils

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.

    2009-03-01

    Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated

  18. Basics of soil fertility management

    OpenAIRE

    Berner, Alfred

    2013-01-01

    The brochure highlights the soil fertility from various scientific and farming perspectives. Its aims to supplement practical observations of farmers, to encourage them to reconsider their relation to their soil and to practice a truly sustainable soil culture. The booklet tries to achieve this goal by providing information on soil matter such as important soil organisms and soil characteristics like root density, soil structure and alkalinity and by showing possibilities of how to ass...

  19. How Can Soil Electrical Conductivity Measurements Control Soil Pollution?

    Directory of Open Access Journals (Sweden)

    Mohammad Reza

    2010-10-01

    Full Text Available Soil pollution results from the build up of contaminants, toxic compounds, radioactive materials, salts, chemicals and cancer-causing agents. The most common soil pollutants are hydrocarbons, heavy metals (cadmium, lead, chromium, copper, zinc, mercury and arsenic, herbicides, pesticides, oils, tars, PCBs and dioxins. Soil Electrical Conductivity (EC is one of the soil physical properties w hich have a good relationship with the other soil characteristics. As measuring soil electrical conductivity is easier, less expensive and faster than other soil properties measurements, using a detector that can do on the go soil EC measurements is a good tool for obtaining useful information about soil pollution condition.

  20. 西石门矿地下尾矿库安全回填项目环境影响及对策%Impacts of Backfilling Mine Tailings on Environment and a New Approach to Reduce Adverse Impacts of Xishimen Mine

    Institute of Scientific and Technical Information of China (English)

    钱金平

    2001-01-01

    The disposal of tailings is a key technical core for mining. Xishimen mine is adopting advanced technology for treating subterranean tailings by secondary concentration and dehydration. The treated tailings of mine could then be safely backfilled into underground, facilitating reducing adverse environmental impacts of mining.%介绍了西石门铁矿尾矿安全回填工程的基本情况,分析了地下尾矿库的库体安全性及环境影响并提出了相关对策。结论认为,西石门矿采用地下尾矿库技术,最大程度地减少了地面尾矿库对环境产生的不良影响,有利于尾矿库区的生态恢复。

  1. Advances in soil dynamics

    DEFF Research Database (Denmark)

    Advances in Soil Dynamics, Volume 3, represents the culmination of the work undertaken by the Advances in Soil Dynamics Monograph Committee, PM-45-01, about 15 years ago to summarize important developments in this field over the last 35 years. When this project was initiated, the main goal...... was to abridge major strides made in the general area of soil dynamics during the sixties, seventies, and eighties. However, by about the mid-nineties soil dynamics research in the US and much of the developed world had come to a virtual standstill. Although significant progress was made prior to the mid......-nineties, we still do not have a sound fundamental knowledge of soil-machine and soil-plant interactions. It is the hope of the editors that these three volumes will provide a ready reference for much needed future research in this area....

  2. Soil microbiota of the prairie

    Science.gov (United States)

    The prairie ecosystem is often used as a benchmark ecosystem to provide a reference soil quality or soil health assessment. Current soil health assessments include measurements of soil chemical and physical indicators and of selected microbiological activities but no characterization of soil microbi...

  3. Managing to enhance soil health

    Science.gov (United States)

    Healthy soils are critical for meeting current and future societal demands. Management strategies that protect the soil against erosion, build soil organic matter and promote nutrient cycling are ways to enhance soil health. Keeping soils covered and judicious use of agrochemicals are akin to us “hu...

  4. Earthworms and Soil Pollutants

    Directory of Open Access Journals (Sweden)

    Kazuyoshi Tamae

    2011-11-01

    Full Text Available Although the toxicity of metal contaminated soils has been assessed with various bioassays, more information is needed about the biochemical responses, which may help to elucidate the mechanisms involved in metal toxicity. We previously reported that the earthworm, Eisenia fetida, accumulates cadmium in its seminal vesicles. The bio-accumulative ability of earthworms is well known, and thus the earthworm could be a useful living organism for the bio-monitoring of soil pollution. In this short review, we describe recent studies concerning the relationship between earthworms and soil pollutants, and discuss the possibility of using the earthworm as a bio-monitoring organism for soil pollution.

  5. Electrodialytic Soil Remediation

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Hansen, Lene; Hansen, Henrik K.

    1997-01-01

    It is not possible for all heavy metal polluted soils to remediate it by an applied electric field alone. A desorbing agent must in different cases be added to the soil in order to make the process possible or to make it cost effective......It is not possible for all heavy metal polluted soils to remediate it by an applied electric field alone. A desorbing agent must in different cases be added to the soil in order to make the process possible or to make it cost effective...

  6. Soil Survey Geographic (SSURGO) - Kinds and Distribution of Soils

    Data.gov (United States)

    California Department of Resources — This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The...

  7. Soils - Soil Survey Geographic (SSURGO) Data for Montana

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — These data sets are digital soil surveys and generally are the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The...

  8. Measuring soil physical properties to assess soil quality

    OpenAIRE

    Raczkowski, C.W.

    2007-01-01

    Soil quality is the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant, animal and human health. A quantitative assessment of soil quality is invaluable in determining the sustainability of land management systems. Criteria for soil quality assessment are: 1) Choose indicators of soil quality based on the multiple functions of soil that maintain productivity and environmental health, 2)must include s...

  9. Correlation Between Soil Water Retention Capability and Soil Salt Content

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The soil moisture retention capability of Chao soil and coastal saline Chao soil in Shandong and Zhejiang provinces were measured by pressure membrane method. The main factors influencing soil moisture retention capability were studied by the methods of correlation and path analyses. The results indicated that < 0.02mm physical clay and soil salt content were the main factors influencing soil moisture retention capability. At soil suction of 30~50 kPa, the soil salt content would be the dominant factor.

  10. KBRA OPWP Soil Rooting Depth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The...

  11. Tolerable soil erosion in Europe

    Science.gov (United States)

    Verheijen, Frank; Jones, Bob; Rickson, Jane; Smith, Celina

    2010-05-01

    Soil loss by erosion has been identified as an important threat to soils in Europe* and is recognised as a contributing process to soil degradation and associated deterioration, or loss, of soil functioning. From a policy perspective, it is imperative to establish well-defined baseline values to evaluate soil erosion monitoring data against. For this purpose, accurate baseline values - i.e. tolerable soil loss - need to be differentiated at appropriate scales for monitoring and, ideally, should take soil functions and even changing environmental conditions into account. The concept of tolerable soil erosion has been interpreted in the scientific literature in two ways: i) maintaining the dynamic equilibrium of soil quantity, and ii) maintaining biomass production, at a location. The first interpretation ignores soil quality by focusing only on soil quantity. The second approach ignores many soil functions by focusing only on the biomass (particularly crop) production function of soil. Considering recognised soil functions, tolerable soil erosion may be defined as 'any mean annual cumulative (all erosion types combined) soil erosion rate at which a deterioration or loss of one or more soil functions does not occur'. Assumptions and problems of this definition will be discussed. Soil functions can generally be judged not to deteriorate as long as soil erosion does not exceed soil formation. At present, this assumption remains largely untested, but applying the precautionary principle appears to be a reasonable starting point. Considering soil formation rates by both weathering and dust deposition, it is estimated that for the majority of soil forming factors in most European situations, soil formation rates probably range from ca. 0.3 - 1.4 t ha-1 yr-1. Although the current agreement on these values seems relatively strong, how the variation within the range is spatially distributed across Europe and how this may be affected by climate, land use and land management

  12. Soil and vegetation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.

    1995-06-01

    Soil sampling and analysis evaluates long-term contamination trends and monitors environmental radionuclide inventories. This section of the 1994 Hanford Site Environmental Report summarizes the soil and vegetation surveillance programs which were conducted during 1994. Vegetation surveillance is conducted offsite to monitor atmospheric deposition of radioactive materials in areas not under cultivation and onsite at locations adjacent to potential sources of radioactivity.

  13. Soil and Culture

    Science.gov (United States)

    Editors Ed Landa and Christian Feller have assembled an international ensemble cast of writers, artists, historians, philosophers, and scientists of broad perspective to create a book of truly fascinating reading for any soils enthusiast. When so little we see in print is truly new or original, Soil...

  14. Contaminated soil concrete blocks

    NARCIS (Netherlands)

    Korte, de A.C.J.; Brouwers, H.J.H.; Limbachiya, Mukesh C.; Kew, Hsein Y.

    2009-01-01

    According to Dutch law the contaminated soil needs to be remediated or immobilised. The main focus in this article is the design of concrete blocks, containing contaminated soil, that are suitable for large production, financial feasible and meets all technical and environmental requirements. In ord

  15. Soil Health Educational Resources

    Science.gov (United States)

    Hoorman, James J.

    2015-01-01

    Soil health and cover crops are topics of interest to farmers, gardeners, and students. Three soil health and cover crop demonstrations provide educational resources. Demonstrations one outlines two educational cover crop seed displays, including the advantages and disadvantages. Demonstration two shows how to construct and grow a cover crop root…

  16. Diffusion in aggregated soil.

    NARCIS (Netherlands)

    Rappoldt, C.

    1992-01-01

    The structure of an aggregated soil is characterized by the distribution of the distance from an arbitrary point in the soil to the nearest macropore or crack. From this distribution an equivalent model system is derived to which a diffusion model can be more easily applied. The model system consist

  17. Mycophagous soil bacteria

    NARCIS (Netherlands)

    Rudnick, M.B.

    2015-01-01

    Abstract

    Soil microorganisms evolved several strategies to compete for limited nutrients in soil. Bacteria of the genus Collimonas developed a way to exploit fungi as a source of organic nutrients. This strategy has been termed “mycophagy&r

  18. Creative Soil Conservation

    Science.gov (United States)

    Smith, Martha

    2010-01-01

    Take plant lessons outdoors with this engaging and inquiry-based activity in which third-grade students learn how to apply soil conservation methods to growing plants. They also collect data and draw conclusions about the effectiveness of their method of soil conservation. An added benefit to this activity is that the third-grade students played…

  19. Electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Karlsmose, Bodil; Ottosen, Lisbeth M.; Hansen, Lene

    1999-01-01

    prevents the protons and the hydroxides ions from the electrode processes to enter the soil. The heavy metals are collected in a concentration compartment, which is separated from the soil by ion-exchange membranes. Examples from remediation experiments are shown, and it is demonstrated that it is possible...

  20. The Soil Series in Soil Classifications of the United States

    Science.gov (United States)

    Indorante, Samuel; Beaudette, Dylan; Brevik, Eric C.

    2014-05-01

    Organized national soil survey began in the United States in 1899, with soil types as the units being mapped. The soil series concept was introduced into the U.S. soil survey in 1903 as a way to relate soils being mapped in one area to the soils of other areas. The original concept of a soil series was all soil types formed in the same parent materials that were of the same geologic age. However, within about 15 years soil series became the primary units being mapped in U.S. soil survey. Soil types became subdivisions of soil series, with the subdivisions based on changes in texture. As the soil series became the primary mapping unit the concept of what a soil series was also changed. Instead of being based on parent materials and geologic age, the soil series of the 1920s was based on the morphology and composition of the soil profile. Another major change in the concept of soil series occurred when U.S. Soil Taxonomy was released in 1975. Under Soil Taxonomy, the soil series subdivisions were based on the uses the soils might be put to, particularly their agricultural uses (Simonson, 1997). While the concept of the soil series has changed over the years, the term soil series has been the longest-lived term in U.S. soil classification. It has appeared in every official classification system used by the U.S. soil survey (Brevik and Hartemink, 2013). The first classification system was put together by Milton Whitney in 1909 and had soil series at its second lowest level, with soil type at the lowest level. The second classification system used by the U.S. soil survey was developed by C.F. Marbut, H.H. Bennett, J.E. Lapham, and M.H. Lapham in 1913. It had soil series at the second highest level, with soil classes and soil types at more detailed levels. This was followed by another system in 1938 developed by M. Baldwin, C.E. Kellogg, and J. Thorp. In this system soil series were again at the second lowest level with soil types at the lowest level. The soil type

  1. The Changing Model of Soil

    Science.gov (United States)

    Richter, D. D.; Yaalon, D.

    2012-12-01

    The contemporary genetic model of soil is changing rapidly in response to advances in soil science and to human and environmental forcings in the 21st century (Richter and Yaalon, 2012). Three ongoing changes in the model of soil include that: (1) lower soil boundaries are much deeper than the solum, historically the O to B horizons, (2) most soils are polygenetic paleosols, products of soil-forming processes that have ranged widely over soils' lifetimes, and (3) soils are globally human-natural bodies, no longer natural bodies. Together, these changes in the model of soil mean that human forcings are a global wave of soil polygenesis altering fluxes of matter and energy and transforming soil thermodynamics as potentially very deep systems. Because soils are non-linear systems resulting from high-order interactions of physics, chemistry, and biology, trajectories of how human forcings alter soils over decades are not readily predictable and require long-term soil observations. There is much to learn about how soils are changing internally as central components of management systems and externally in relation to wider environments. To be critical, research has been remarkably superficial in studies of soil, reductionist in approach, and lacking in time-series observations of responses to soil management. While this criticism may sound negative, it creates significant opportunities for contemporary soil scientists.

  2. Climate-smart soils

    Science.gov (United States)

    Paustian, Keith; Lehmann, Johannes; Ogle, Stephen; Reay, David; Robertson, G. Philip; Smith, Pete

    2016-04-01

    Soils are integral to the function of all terrestrial ecosystems and to food and fibre production. An overlooked aspect of soils is their potential to mitigate greenhouse gas emissions. Although proven practices exist, the implementation of soil-based greenhouse gas mitigation activities are at an early stage and accurately quantifying emissions and reductions remains a substantial challenge. Emerging research and information technology developments provide the potential for a broader inclusion of soils in greenhouse gas policies. Here we highlight ‘state of the art’ soil greenhouse gas research, summarize mitigation practices and potentials, identify gaps in data and understanding and suggest ways to close such gaps through new research, technology and collaboration.

  3. 气泡混合轻质土工程的主要特性与施工质量管理及控制%Main Characteristics of Bubble Mixed Light Soil Engineering and Construction Quality Management and Control

    Institute of Scientific and Technical Information of China (English)

    王敏杰

    2015-01-01

    结合广州蓄能水电厂永久公路水毁维修工程气泡混合轻质土路基回填施工实践,论述气泡混合轻质土的主要特性与施工质量管理及控制。气泡混合轻质土具有流动性强、水溶性高、施工方便和节省成本等特点,只要做好施工过程中的质量管理及控制,在未来的工程施工中也将会有很大的发展空间,具有很高的市场前景和推广价值。%Combining with the construction practice of bubble mixed light soil roadbed backfill of flood damage highway repair engineering in Guangzhou pumped storage power plant permanent, the main characteristics of bubble mixed light soil and construction quality management and control are discussed.Bubble mixed light soil has strong liquidity,high solubility in water,convenient construction and cost saving features.As long as good quality management and control are realized in construction process,it will have great room for development,very high market prospect and popularization value in the future engineering construction.

  4. Geostatistical characterization of soil pollution at industrial sites Case of polycyclic aromatic hydrocarbons at former coking plants; Caracterisation geostatistique de pollutions industrielles de sols cas des hydrocarbures aromatiques polycycliques sur d'anciens sites de cokeries

    Energy Technology Data Exchange (ETDEWEB)

    Jeannee, N.

    2001-05-15

    Estimating polycyclic aromatic hydrocarbons concentrations in soil at former industrial sites poses several practical problems on account of the properties of the contaminants and the history of site: 1)collection and preparation of samples from highly heterogeneous material, 2) high short scale variability, particularly in presence of backfill, 3) highly contrasted grades making the vario-gram inference complicated. The sampling strategy generally adopted for contaminated sites is based on the historical information. Systematic sampling recommended for geostatistical estimation is often considered to be excessive and unnecessary. Two former coking plants are used as test cases for comparing several geostatistical methods for estimating (i) in situ concentrations and (ii) the probability that they are above a pollution threshold. Several practical and methodological questions are considered: 1) the properties of various estimators of the experimental vario-gram and the validity of the results; 2) the use of soft data, such as historical information, organoleptic observations and semi-quantitative methods, with a view to improve the precision of the estimates; 3) the comparison of standard sampling strategies, taking into account vertical repartition of grades and the history of the site. Multiple analyses of the same sample give an approximation of the sampling error. Short scale sampling shows the difficulty of selecting soils in the absence of a spatial structure. Sensitivity studies are carried out to assess how densely sampled soft data can improve estimates. By using mainly existing models, this work aims at giving practical recommendations for the characterization of soil pollution. (author)

  5. Relaxometry in soil science

    Science.gov (United States)

    Schaumann, G. E.; Jaeger, F.; Bayer, J. V.

    2009-04-01

    NMR relaxometry is a sensitive, informative and promising method to study pore size distribution in soils as well as many kinds of soil physicochemical processes, among which are wetting, swelling or changes in the macromolecular status. Further, it is a very helpful method to study interactions between molecules in soil organic matter and it can serve to study the state of binding of water or organic chemicals to soil organic matter. The method of Relaxometry excite the nuclei of interest and their relaxation kinetics are observed. The relaxation time is the time constant of this first order relaxation process. Most applications of relaxometry concentrate on protons, addressing water molecules or H-containing organic molecules. In this context, 1H-NMR relaxometry may be used as an analysis method to determine water uptake characteristics of soils, thus gaining information about water distribution and mobility as well as pore size distribution in wet and moist samples. Additionally, it can also serve as a tool to study mobility of molecular segments in biopolymers. Principally, relaxometry is not restricted to protons. In soil science, relaxometry is also applied using deuterium, xenon and other nuclei to study pore size distribution and interactions. The relaxation time depends on numerous parameters like surface relaxivity, diffusion and interactions between nuclei as well as between nuclei and the environment. One- and two-dimensional methods address the relation between relaxation time and diffusion coefficients and can give information about the interconnectivity of pores. More specific information can be gained using field cycling techniques. Although proton NMR relaxometry is a very promising method in soil science, it has been applied scarcely up to now. It was used to assess changes in molecular rigidity of humic substances. A very recent study shows the potential of NMR relaxometry to assess the pore size distribution of soils in a fast and non

  6. 考虑土拱效应的刚性挡墙主动土压力分析%Analysis of active earth pressure on rigid retaining walls considering soil arching

    Institute of Scientific and Technical Information of China (English)

    王杰; 夏唐代; 贺鹏飞; 黄博

    2014-01-01

    以墙后填土为无黏性土的刚性挡土墙为研究对象,考虑墙后土体的土拱效应,修改了 Shubhra Geol 抛物线形土拱表达式,推导了对应不同内摩擦角和墙-土摩擦角的挡土墙平动模式下的主动土压力系数。基于水平微分单元法,得到考虑土拱效应的主动土压力分布、合力大小和合力作用点高度的理论表达式,并与现有经典理论解及前人理论研究成果和模型试验数据进行对比分析,结果表明,主动土压力与墙-土接触面摩擦角、土体内摩擦角、土体重度和挡墙高度相关,土压力分布为非线性,与其他结果比较吻合,从而验证了该研究成果的正确性。%Taking a rigid retaining wall with cohesionless backfill for example, considering the soil arching, the active earth pressure factor is derived for retaining wall under translation mode with different internal friction angles and wall-soil friction angles. The Shubhra Geol parabolic soil arching expression is modified. Based on horizontal differential element method, new formulations are proposed for calculating the active earth pressure, the resultant earth pressure and its action point. In order to check the accuracy of the proposed formulation, the predictions from the equation are compared with the results of full-scale test and existing classical theory. The results show that the active earth pressure is related to wall-soil friction angle, the internal friction angle, the unit weight of backfill and the height of retaining wall. It is shown that the earth pressure is nonlinear and the previous research results show great agreement with each other;and the correctness of the results is verified.

  7. Why is the influence of soil macrofauna on soil structure only considered by soil ecologists ?

    OpenAIRE

    Bottinelli, N.; Jouquet, Pascal; CAPOWIEZ, Y.; Podwojewski, Pascal; Grimaldi,Michel; Peng, X.

    2015-01-01

    These last twenty years have seen the development of an abundant literature on the influence of soil macrofauna on soil structure. Amongst these organisms, earthworms, termites and ants are considered to play a key role in regulating the physical, chemical and microbiological properties of soils. Due to these influential impacts, soil ecologists consider these soil macro-invertebrates as ‘soil engineers’ and their diversity and abundance are nowadays considered as relevant bioindi...

  8. Soil bacteria for remediation of polluted soils

    Energy Technology Data Exchange (ETDEWEB)

    Springael, D.; Bastiaens, L.; Carpels, M.; Mergaey, M.; Diels, L.

    1996-09-18

    Soil bacteria, specifically adapted to contaminated soils, may be used for the remediation of polluted soils. The Flemish research institute VITO has established a collection of bacteria, which were isolated from contaminated areas. This collection includes microbacteria degrading mineral oils (Pseudomonas sp., Acinetobacter sp. and others), microbacteria degrading polycyclic aromatic hydrocarbons (genera Sphingomonas and Mycobacterium), microbacteria degrading polychlorobiphenyls (genus Ralstonia and strains related to beta-Proteobacteria), and metal resistant bacteria with plasmid borne resistances to Cd, Zn, Ni, Co, Cu, Hg, and Cr. Bench-scale reactors were developed to investigate the industrial feasibility of bioremediation. Batch Stirred Tank Reactors were used to evaluate the efficiency of oil degraders. Soils, contaminated with non-ferrous metals, were treated using a Bacterial Metal Slurry Reactor. It was found that the reduction of the Cd concentration may vary strongly from sample to sample: reduction factors vary from 95 to 50%. Is was shown that Cd contained in metallic sinter and biologically unavailable Cd could not be removed.

  9. Introductory Soil Science Exercises Using USDA Web Soil Survey

    Science.gov (United States)

    Post, Christopher J.; Mikhailova, Elena; McWhorter, Christopher M.

    2007-01-01

    The USDA, Natural Resource Conservation Service (NRCS) Web Soil Survey is a valuable teaching tool for soil science education. By incorporating the Web Soil Survey into an undergraduate-level course, students are able to use the most detailed digital soil survey information without the steep learning curve associated with geographic information…

  10. Soil disturbance increases soil microbial enzymatic activity in arid ecoregion

    Science.gov (United States)

    Functional diversity of the soil microbial community is commonly used in the assessment of soil health as it relates to the activity of soil microflora involved in carbon cycling. Soil microbes in different microenvironments will have varying responses to different substrates, thus catabolic fingerp...

  11. [Trophic chains in soil].

    Science.gov (United States)

    Goncharov, A A; Tiunov, A V

    2013-01-01

    Trophic links of soil animals are extensively diverse but also flexible. Moreover, feeding activity of large soil saprotrophs often cascades into a range of ecosystem-level consequences via the ecological engineering. Better knowledge on the main sources of energy utilized by soil animals is needed for understanding functional structure of soil animal communities and their participation in the global carbon cycling. Using published and original data, we consider the relative importance of dead organic matter and saprotrophic microorganisms as a basal energy source in the detritus-based food chains, the feeding of endogeic macrofauna on the stabilized soil organic matter, and the role of recent photosynthate in the energy budget of soil communities. Soil food webs are spatially and functionally compartmentalized, though the separation of food chains into bacteria- and fungi-based channels seems to be an over-simplification. The regulation of the litter decomposition rates via top-down trophic interactions across more than one trophic level is only partly supported by experimental data, but mobile litter-dwelling predators play a crucial role in integrating local food webs within and across neighboring ecosystems.

  12. Iodine in soil

    Energy Technology Data Exchange (ETDEWEB)

    Johanson, Karl Johan [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

    2000-12-01

    A literature study of the migration and the appearance of iodine isotopes in the bio-sphere particularly in soil is presented. Some important papers in the field of iodine appearance in soil and the appearance of {sup 129}I in the surroundings of reprocessing plants are discussed. The most important conclusions are: 1. Iodine binds to organic matter in the soil and also to some oxides of aluminium and iron. 2. If the iodine is not bound to the soil a large fraction of added {sup 129}I is volatilized after a rather short period. 3. The binding and also the volatilisation seems to be due to biological activity in the soil. It may take place within living microorganisms or by external enzymes excreted from microorganisms. 4. Due to variations in the composition of soil there may be a large variation in the distribution of {sup 129}I in the vertical profile of soil - usually most of the {sup 129}I in the upper layer - which also results in large variations in the {sup 129}I uptake to plants.

  13. Climate Strategic Soil Management

    Directory of Open Access Journals (Sweden)

    Rattan Lal

    2014-02-01

    Full Text Available The complex and strong link between soil degradation, climate change and food insecurity is a global challenge. Sustainable agricultural systems must be integral to any agenda to address climate change and variability, improve renewable fresh water supply and quality, restore degraded soils and ecosystems and advance food security. These challenges are being exacerbated by increasing population and decreasing per capita arable land area and renewable fresh water supply, the increasing frequency of extreme events, the decreasing resilience of agroecosystems, an increasing income and affluent lifestyle with growing preference towards meat-based diet and a decreasing soil quality and use efficiency of inputs. Reversing these downward spirals implies the implementation of proven technologies, such as conservation agriculture, integrated nutrient management, precision agriculture, agroforestry systems, etc. Restoration of degraded soil and desertified ecosystems and the creation of positive soil and ecosystem C budgets are important. Urban agriculture and green roofs can reduce the energy footprint of production chains for urban and non-urban areas and enhance the recycling of by-products. Researchable priorities include sustainable land use and soil/water management options, judicious soil governance and modus operandi towards payments to land managers for the provisioning of ecosystem services.

  14. Soil washing treatability study

    Energy Technology Data Exchange (ETDEWEB)

    Krstich, M.

    1995-12-01

    Soil washing was identified as a viable treatment process option for remediating soil at the FEMP Environmental Management Project (FEMP). Little information relative to the specific application and potential effectiveness of the soil washing process exists that applies to the types of soil at the FEMP. To properly evaluate this process option in conjunction with the ongoing FEMP Remedial Investigation/Feasibility Study (RI/FS), a treatability testing program was necessary to provide a foundation for a detailed technical evaluation of the viability of the process. In August 1991, efforts were initiated to develop a work plan and experimental design for investigating the effectiveness of soil washing on FEMP soil. In August 1992, the final Treatability Study Work Plan for Operable Unit 5: Soil Washing (DOE 1992) was issued. This document shall be referenced throughout the remainder of this report as the Treatability Study Work Plan (TSWP). The purpose of this treatability study was to generate data to support initial screening and the detailed analysis of alternatives for the Operable Unit 5 FS.

  15. SOIL Geo-Wiki: A tool for improving soil information

    Science.gov (United States)

    Skalský, Rastislav; Balkovic, Juraj; Fritz, Steffen; See, Linda; van der Velde, Marijn; Obersteiner, Michael

    2014-05-01

    Crowdsourcing is increasingly being used as a way of collecting data for scientific research, e.g. species identification, classification of galaxies and unravelling of protein structures. The WorldSoilProfiles.org database at ISRIC is a global collection of soil profiles, which have been 'crowdsourced' from experts. This system, however, requires contributors to have a priori knowledge about soils. Yet many soil parameters can be observed in the field without specific knowledge or equipment such as stone content, soil depth or color. By crowdsourcing this information over thousands of locations, the uncertainty in current soil datasets could be radically reduced, particularly in areas currently without information or where multiple interpretations are possible from different existing soil maps. Improved information on soils could benefit many research fields and applications. Better soil data could enhance assessments of soil ecosystem services (e.g. soil carbon storage) and facilitate improved process-based ecosystem modeling from local to global scales. Geo-Wiki is a crowdsourcing tool that was developed at IIASA for land cover validation using satellite imagery. Several branches are now available focused on specific aspects of land cover validation, e.g. validating cropland extent or urbanized areas. Geo-Wiki Pictures is a smart phone application for collecting land cover related information on the ground. The extension of Geo-Wiki to a mobile environment provides a tool for experts in land cover validation but is also a way of reaching the general public in the validation of land cover. Here we propose a Soil Geo-Wiki tool that builds on the existing functionality of the Geo-Wiki application, which will be largely designed for the collection and sharing of soil information. Two distinct applications are envisaged: an expert-oriented application mainly for scientific purposes, which will use soil science related language (e.g. WRB or any other global reference

  16. Improvement of Soil Physical Properties with Soil Conditioners

    Institute of Scientific and Technical Information of China (English)

    ZHAOBING-ZI; XUFU-AN

    1995-01-01

    Effects of non-ionic polyacrylamide(PAM),anionic polyacrylamide(PHP),cationic polyacrylamide(PCAM),non-ionic polyvinylalcohol(PVA),anionic hydrolyzed polyacrylonitrile(HPAN)and polyethleneoxide(PEO)on the physical properties of three different soil stpes were studied.content of water-stable aggregates larger than 0.25mm increased to varying extents for different soils and soil conditioners,Among the six kinds of condiftioners,non-ionic polyacrylamide(PAM) was the most effective for red soil while polyethyleneoxide(PEO)the least effective for Chao soil,red soil and yellow-brown soil.Water-stable aggregates with the molecular weight of PEO within a certain range.Only evaporation rate of Chao soil decreased after aplication of PAM and HPAN to Chao soil and red soil.

  17. Selenium in soil

    Directory of Open Access Journals (Sweden)

    Čuvardić Maja S.

    2003-01-01

    Full Text Available Selenium (Se is an essential microelement, necessary for normal functioning of human and animal organisms. Its deficiency in food and feed causes a number of diseases. In high concentrations, selenium is toxic for humans animals and plants. Soil provision with selenium affects its level in food and feed via nutrition chain. However, selenium reactivity and bioavailability depends not only on its total content in soil but also on its chemical forms. Distribution of the different forms of selenium depends on soil properties such as reaction, aeration, contents of clay and organic matter and microbiological activity.

  18. Managing compost stability and amendment to soil to enhance soil heating during soil solarization.

    Science.gov (United States)

    Simmons, Christopher W; Guo, Hongyun; Claypool, Joshua T; Marshall, Megan N; Perano, Kristen M; Stapleton, James J; Vandergheynst, Jean S

    2013-05-01

    Soil solarization is a method of soil heating used to eradicate plant pathogens and weeds that involves passive solar heating of moist soil mulched (covered) with clear plastic tarp. Various types of organic matter may be incorporated into soil prior to solarization to increase biocidal activity of the treatment process. Microbial activity associated with the decomposition of soil organic matter may increase temperatures during solarization, potentially enhancing solarization efficacy. However, the level of organic matter decomposition (stability) necessary for increasing soil temperature is not well characterized, nor is it known if various amendments render the soil phytotoxic to crops following solarization. Laboratory studies and a field trial were performed to determine heat generation in soil amended with compost during solarization. Respiration was measured in amended soil samples prior to and following solarization as a function of soil depth. Additionally, phytotoxicity was estimated through measurement of germination and early growth of lettuce seedlings in greenhouse assays. Amendment of soil with 10%(g/g) compost containing 16.9 mg CO2/gdry weight organic carbon resulted in soil temperatures that were 2-4 °C higher than soil alone. Approximately 85% of total organic carbon within the amended soil was exhausted during 22 days of solarization. There was no significant difference in residual respiration with soil depth down to 17.4 cm. Although freshly amended soil proved highly inhibitory to lettuce seed germination and seedling growth, phytotoxicity was not detected in solarized amended soil after 22 days of field solarization.

  19. Effect of different soil washing solutions on bioavailability of residual arsenic in soils and soil properties.

    Science.gov (United States)

    Im, Jinwoo; Yang, Kyung; Jho, Eun Hea; Nam, Kyoungphile

    2015-11-01

    The effect of soil washing used for arsenic (As)-contaminated soil remediation on soil properties and bioavailability of residual As in soil is receiving increasing attention due to increasing interest in conserving soil qualities after remediation. This study investigates the effect of different washing solutions on bioavailability of residual As in soils and soil properties after soil washing. Regardless of washing solutions, the sequential extraction revealed that the residual As concentrations and the amount of readily labile As in soils were reduced after soil washing. However, the bioassay tests showed that the washed soils exhibited ecotoxicological effects - lower seed germination, shoot growth, and enzyme activities - and this could largely be attributed to the acidic pH and/or excessive nutrient contents of the washed soils depending on washing solutions. Overall, this study showed that treated soils having lower levels of contaminants could still exhibit toxic effects due to changes in soil properties, which highly depended on washing solutions. This study also emphasizes that data on the As concentrations, the soil properties, and the ecotoxicological effects are necessary to properly manage the washed soils for reuses. The results of this study can, thus, be utilized to select proper post-treatment techniques for the washed soils.

  20. Two Centuries of Soil Conservation.

    Science.gov (United States)

    Helms, Douglas

    1991-01-01

    Narrates U.S. soil conservation history since the late eighteenth century. Discusses early practices such as contour plowing. Profiles individuals who promoted soil conservation and were largely responsible for the creation of the Soil Conservation Service. Explains the causes of erosion and how soil conservation districts help farmers prevent…

  1. Mycotoxins in the soil environment

    OpenAIRE

    Elmholt, S.

    2008-01-01

    The paper outlines the current knowledge concerning fate of mycotoxins in the soil environment, including - outline of mycotoxins addressed (trichothecenes, zearalenone, fumonisins, aflatoxins, ochratoxins and patulin) - routes by which the mycotoxins enter the soil environment - routes by which they are immobilised or removed from the soil environment - mycotoxigenic fungi and mycotoxins in the soil environment

  2. Soil and soil environmental quality monitoring in China: a review.

    Science.gov (United States)

    Teng, Yanguo; Wu, Jin; Lu, Sijin; Wang, Yeyao; Jiao, Xudong; Song, Liuting

    2014-08-01

    Over the past few decades, numerous concerns have been raised in China over the issue of environmental sustainability. Various soil survey and monitoring programs have been carried out in China to study soil quality, and to provide a scientific basis for environment policy making. This paper provides an overview of past and current soil quality surveys and monitoring activities in China. This paper includes a summary of concerns over background concentrations of elements in soil, and soil environmental standards and guidelines in China. Levels of pollution in urban soil, agricultural soil, and soil in mining and smelting areas were compared using the concentrations and pollution indexes. In addition to soil surveys, soil monitoring is essential to study the data and to examine the effects of contaminants in soils. However, the current soil quality monitoring system was insufficient to accurately determine the soil quality status of soils across China. For accurate soil monitoring in China, it will be necessary to set up routine monitoring systems at various scales (national, provincial, and local scales), taking into consideration monitoring indicators and quality assurance. This is currently an important priority for the environmental protection administration of China.

  3. Effect of soil property on evaporation from bare soils

    Science.gov (United States)

    Zhang, Chenming; Li, Ling; Lockington, David

    2015-04-01

    Quantifying the actual evaporation rate from bare soils remains a challenging task as it not only associates with the atmospheric demand and liquid water saturation on the soil surface, but also the properties of the soils (e.g., porosity, pore size distribution). A physically based analytical model was developed to describe the surface resistance varying with the liquid water saturation near the soil surface. This model considers the soil pore size distribution, hydraulic connection between the main water cluster and capillary water in the soil surface when the soil surface is wet and the thickness of the dry soil layer when the soil surface is dry. The surface resistance model was then integrated to a numerical model based on water balance, heat balance and surface energy balance equations. The integrated model was validated by simulating water and heat transport processes during six soil column drying experiments. The analysis indicates that the when soil surface is wet, the consideration of pore size distribution in the surface resistance model offers better estimation of transient evaporation among different soil types than the estimations given by empirically based surface resistance models. Under fixed atmospheric boundary condition and liquid water saturation, fine sand has greater evaporation rate than coarse sand as stronger capillary force devlivers more water from the main water cluster. When the soil surface becomes dry, the impact of soil property to evaporation becomes trivial as the thickness of the dry soil layer turns to be the key factor to determine the evaporation rate.

  4. European Atlas of Soil Biodiversity

    DEFF Research Database (Denmark)

    Krogh (contributor), Paul Henning

    on Earth, life within the soil is often hidden away and suffers by being 'out of sight and out of mind'. What kind of life is there in soil? What do we mean by soil biodiversity? What is special about soil biology? How do our activities affect soil ecosystems? What are the links between soil biota...... and climate change? The first ever European Atlas of Soil Biodiversity uses informative texts, stunning photographs and maps to answer these questions and other issues. The European Atlas of Soil Biodiversity functions as a comprehensive guide allowing non-specialists to access information about this unseen...... Biodiversity'. Starting with the smallest organisms such as the bacteria, this segment works through a range of taxonomic groups such as fungi, nematodes, insects and macro-fauna to illustrate the astonishing levels of heterogeneity of life in soil. The European Atlas of Soil Biodiversity is more than just...

  5. The Soil Mobilome

    DEFF Research Database (Denmark)

    Luo, Wenting

    Soil is considered a reservoir of diverse bacterial cellular functions, of which resistance mechanisms towards biological antimicrobial agents are of substantial interest to us. Previous findings report that the long-term accumulation of copper in an agricultural soil significantly affects......-selected for among natural bacterial populations. One possible explanation is the horizontal transfer of resistance genes among soil bacteria mediated by mobile genetic elements, such as plasmids, integrons, transposons and bacteriophages, of which copper and antibiotic resistance genes can be linked on the same...... mobile elements. To test this hypothesis, we collected non-polluted and CuSO4- contaminated soil samples and attempted to describe the co-selection of plasmid-encoded copper and antimicrobial resistance via both an endogenous plasmid isolation approach as well as a plasmid metagenomic approach...

  6. Soils - Mean Permeability

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital spatial data set provides information on the magnitude and spatial pattern of depth-weighted, mean soil permeability throughout the State of Kansas. The...

  7. CPC Soil Moisture

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The monthly data set consists of a file containing 1/2 degree monthly averaged soil moisture water height equivalents for the globe from 1948 onwards. Values are...

  8. National Geochemical Database: Soil

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Geochemical analysis of soil samples from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are from the continental US...

  9. Metals in urban playground soils

    OpenAIRE

    Ljung, Karin

    2006-01-01

    Urban soils generally have elevated metal contents originating from both point and diffuse pollution sources. Urban areas designated for children, who are most susceptible to any negative health effects of soil metals, may therefore have elevated soil metal contents. Children ingest soil both directly and by putting dirty hands and objects in their mouths. The soil ingested involuntarily mainly comprise very fine particles that have a larger surface area for sorption and may therefore hold hi...

  10. 软基地段明洞不均匀沉降后的回填安全性及加固措施研究%Study on Backfilling Safety and Reinforcement Technology of Open-cut Tunnel with Differential Settlement in Soft Ground

    Institute of Scientific and Technical Information of China (English)

    程正明

    2012-01-01

    Stress-structure model is used to study the backfilling safety and reinforcement technology of the open-cut sec- tion of Xiang' an sub-sea tunnel with differential settlement in soft ground. The study results show that the predicted val- ue of the differential settlement of the open-cut tunnel is 80 mm, and the minima safety coefficient is 2. l 1. Although the structural safety coefficient meets the requirements, the differential settlement may induce cracks, dislocations and water seepage, which has serious effects on the operation function and durability of the tunnel. Countermeasures, including re- inforcing the arch feet by large-diameter root piles, reinforcing the invert by TSS steel pipe grouting, crack sealing by grouting, and backfilling symmetrically and layer by layer, are proposed. The monitoring results show that the predicted settlement coincides well with the measured settlement, the reinforcement has achieved good effect, and the displace- ment has been brought under effective control.%为分析厦门翔安海底隧道软基地段明洞不均匀沉降后的回填安全性和加固措施,采用荷载一结构模型进行研究。综合研究结论如下:1)填土后明洞差异沉降预测值为80mm,最小安全系数为2.11,虽然结构安全系数满足要求,但不均匀沉降将导致裂缝、错台及渗水,严重影响隧道使用功能和耐久性;2)提出采用大孔径树根桩加固明洞衬砌两侧拱脚,TSS钢花管注浆加固仰拱中央,灌浆封闭裂缝,分层对称填土的综合处理方案;3)经现场监测验证,预测沉降规律与实测吻合较好,加固措施成效良好,变形得到治理。

  11. Soil degradation effect on biological activity in Mediterranean calcareous soils

    Science.gov (United States)

    Roca-Pérez, L.; Alcover-Sáez, S.; Mormeneo, S.; Boluda, R.

    2009-04-01

    Soil degradation processes include erosion, organic matter decline, compaction, salinization, landslides, contamination, sealing and biodiversity decline. In the Mediterranean region the climatological and lithological conditions, together with relief on the landscape and anthropological activity are responsible for increasing desertification process. It is therefore considered to be extreme importance to be able to measure soil degradation quantitatively. We studied soil characteristics, microbiological and biochemical parameters in different calcareous soil sequences from Valencia Community (Easter Spain), in an attempt to assess the suitability of the parameters measured to reflect the state of soil degradation and the possibility of using the parameters to assess microbiological decline and soil quality. For this purpose, forest, scrubland and agricultural soil in three soil sequences were sampled in different areas. Several sensors of the soil biochemistry and microbiology related with total organic carbon, microbial biomass carbon, soil respiration, microorganism number and enzyme activities were determined. The results show that, except microorganism number, these parameters are good indicators of a soil biological activity and soil quality. The best enzymatic activities to use like indicators were phosphatases, esterases, amino-peptidases. Thus, the enzymes test can be used as indicators of soil degradation when this degradation is related with organic matter losses. There was a statistically significant difference in cumulative O2 uptake and extracellular enzymes among the soils with different degree of degradation. We would like to thank Spanish government-MICINN for funding and support (MICINN, project CGL2006-09776).

  12. A modified soil water based Richards equation for layered soils

    Science.gov (United States)

    Kalinka, F.; Ahrens, B.

    2010-09-01

    Most Soil-Vegetation-Atmosphere-Transfer (SVAT) models like TERRA-ML (implemented e.g. in the CCLM model (www.clm-community.eu)) use the soil moisture based Richards equation to simulate vertical water fluxes in soils, assuming a homogeneous soil type. Recently, high-resolution soil type datasets (e.g. BüK 1000, only for Germany (Federal Institute for Geosciences and Natural Resources, BGR, www.bgr.bund.de) or Harmonized World Soil Database (HWSD, version 1.1, FAO/IIASA/ISRIC/ISSCAS/JRC, March 2009)) have been developed. Deficiencies in the numerical solution of the soil moisture based Richards equation may occur if inhomogeneous soil type data is implemented, because there are possibly discontinuities in soil moisture due to various soil type characteristics. One way to fix this problem is to use the potential based Richards equation, but this may lead to problems in conservation of mass. This presentation will suggest a possible numerical solution of the soil moisture based Richards equation for inhomogeneous soils. The basic idea is to subtract the equilibrium state of it from soil moisture fluxes. This should reduce discontinuities because each soil layer aspires the equilibrium state and therefore differences might be of the same order. First sensitivity studies have been done for the Main river basin, Germany.

  13. Solute diffusivity in undisturbed soil

    DEFF Research Database (Denmark)

    Lægdsmand, Mette; Møldrup, Per; Schjønning, Per

    2012-01-01

    Solute diffusivity in soil plays a major role in many important processes with relation to plant growth and environmental issues. Soil solute diffusivity is affected by the volumetric water content as well as the morphological characteristics of water-filled pores. The solute diffusivity in intact...... soil samples from two different tillage treatments (soil from below the depth of a harrow treatment and soil from within a moldboard plowed plow layer) was estimated based on concentration profiles using a newly developed method. The method makes use of multiple tracers (two sets of counterdiffusing...... tracers) for a better determination of the diffusivity. The diffusivity was higher in the below-till soil than the plowed soil at the same soil water matric potential due to higher water content but also due to higher continuity and lower tortuosity of the soil pores. We measured identical solute...

  14. Soil functional types: surveying the biophysical dimensions of soil security

    Science.gov (United States)

    Cécillon, Lauric; Barré, Pierre

    2015-04-01

    Soil is a natural capital that can deliver key ecosystem services (ES) to humans through the realization of a series of soil processes controlling ecosystem functioning. Soil is also a diverse and endangered natural resource. A huge pedodiversity has been described at all scales, which is strongly altered by global change. The multidimensional concept soil security, encompassing biophysical, economic, social, policy and legal frameworks of soils has recently been proposed, recognizing the role of soils in global environmental sustainability challenges. The biophysical dimensions of soil security focus on the functionality of a given soil that can be viewed as the combination of its capability and its condition [1]. Indeed, all soils are not equal in term of functionality. They show different processes, provide different ES to humans and respond specifically to global change. Knowledge of soil functionality in space and time is thus a crucial step towards the achievement soil security. All soil classification systems incorporate some functional information, but soil taxonomy alone cannot fully describe the functioning, limitations, resistance and resilience of soils. Droogers and Bouma [2] introduced functional variants (phenoforms) for each soil type (genoform) so as to fit more closely to soil functionality. However, different genoforms can have the same functionality. As stated by McBratney and colleagues [1], there is a great need of an agreed methodology for defining the reference state of soil functionality. Here, we propose soil functional types (SFT) as a relevant classification system for the biophysical dimensions of soil security. Following the definition of plant functional types widely used in ecology, we define a soil functional type as "a set of soil taxons or phenoforms sharing similar processes (e.g. soil respiration), similar effects on ecosystem functioning (e.g. primary productivity) and similar responses to global change (land-use, management or

  15. Prediction of soil organic carbon concentration and soil bulk density of mineral soils for soil organic carbon stock estimation

    Science.gov (United States)

    Putku, Elsa; Astover, Alar; Ritz, Christian

    2016-04-01

    Soil monitoring networks provide a powerful base for estimating and predicting nation's soil status in many aspects. The datasets of soil monitoring are often hierarchically structured demanding sophisticated data analyzing methods. The National Soil Monitoring of Estonia was based on a hierarchical data sampling scheme as each of the monitoring site was divided into four transects with 10 sampling points on each transect. We hypothesized that the hierarchical structure in Estonian Soil Monitoring network data requires a multi-level mixed model approach to achieve good prediction accuracy of soil properties. We used this database to predict soil bulk density and soil organic carbon concentration of mineral soils in arable land using different statistical methods: median approach, linear regression and mixed model; additionally, random forests for SOC concentration. We compared the prediction results and selected the model with the best prediction accuracy to estimate soil organic carbon stock. The mixed model approach achieved the best prediction accuracy in both soil organic carbon (RMSE 0.22%) and bulk density (RMSE 0.09 g cm-3) prediction. Other considered methods under- or overestimated higher and lower values of soil parameters. Thus, using these predictions we calculated the soil organic carbon stock of mineral arable soils and applied the model to a specific case of Tartu County in Estonia. Average estimated SOC stock of Tartu County is 54.8 t C ha-1 and total topsoil SOC stock 1.8 Tg in humus horizon.

  16. Soil Microbial Mineralization of Cellulose in Frozen Soils

    Science.gov (United States)

    Segura, J.; Haei, M.; Sparrman, T.; Nilsson, M. B.; Schleucher, J.; Oquist, M. G.

    2014-12-01

    Soils of high-latitude ecosystems store a large fraction of the global soil carbon pool. In boreal forests, the mineralization of soil organic matter (SOM) during winter by soil heterotrophic activity can affect the ecosystems net carbon balance. Recent research has shown that microorganisms in the organic surface layer of boreal forest soil can mineralize and grow on simple, monomeric substrates under frozen conditions. However, any substantial impacts of microbial activity in frozen soils on long-term soil carbon balances depend on whether soil microorganisms can utilize the more complex, polymeric substrates in SOM. In order to evaluate the potential for soil microorganisms to metabolize carbon polymers at low temperatures, we incubated boreal forest soil samples amended with [13C]-cellulose and studied the microbial catabolic and anabolic utilization of the substrate under frozen and unfrozen conditions (-4 and +4°C). The [13C]-CO2 production rate in the samples at +4°C were 0.524 mg CO2 SOM -1 day-1 while rates in the frozen samples (-4°C) were 0.008 mg CO2 SOM -1 day-1. Thus, freezing of the soil markedly reduced microbial utilization of the cellulose. However, newly synthetized [13C]-enriched cell membrane lipids, PLFAs, were detected in soil samples incubated both above and below freezing, confirming microbial growth also in the frozen soil matrix. The reduced metabolic rates induced by freezing indicate constraints on exoenzymatic activity, as well as substrate diffusion rates that we can attribute to reduced liquid water content of the frozen soil. We conclude that the microbial population in boreal forest soil has the capacity to metabolize, and grow, on polymeric substrates at temperatures below zero. This also involves maintaining exoenzymatic activity in frozen soils. This capacity manifests the importance of SOM mineralization during the winter season and its importance for the net carbon balance of soils of high-latitude ecosystems.

  17. Soil mechanics and analysis of soils overlying cavitose bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Drumm, E.C.

    1987-08-01

    The stability of the residual soils existing at the West Chestnut Ridge Site, Oak Ridge Reservation, Tennessee, was evaluated. The weathered bedrock below this residual soil contains numerous solution cavities, and several karst features were identified. The West Chestnut Ridge site was evaluated with respect to deformation and collapse of the residual soil into the bedrock cavities. A finite element analysis investigated the effects of bedrock cavity radius, thickness of soil overburden, and surface surcharge upon the deformational and stability characteristics of the residual soil. The results indicate that for small cavity radii, the thickness of the soil cover has little effect on the zone of yielded soil. For large cavity radii, a smaller zone of distressed soil occurs under thick soil cover than under thin soil cover. Dimensionless curves are presented to enable the prediction of the vertical extent of the zone of yielded soil for a range of site geometries. Although the thick soil deposits (100 feet or greater) typically found on the ridges result in high stresses adjacent to the cavity, the area of the distressed or yielded soil is small and unlikely to extend to the surface. In addition, the surface deformation or subsidence is expected to be minimal. Thus, the siting of waste facilities on the ridges where the overburden is maximum would tend to reduce the effects of deformation into the cavities. 29 refs., 37 figs., 7 tabs.

  18. Ferrihydrite in soils

    Science.gov (United States)

    Vodyanitskii, Yu. N.; Shoba, S. A.

    2016-07-01

    Ferrihydrite—an ephemeral mineral—is the most active Fe-hydroxide in soils. According to modern data, the ferrihydrite structure contains tetrahedral lattice in addition to the main octahedral lattice, with 10-20% of Fe being concentrated in the former. The presence of Fe tetrahedrons influences the surface properties of this mineral. The chemical composition of ferrihydrite samples depends largely on the size of lattice domains ranging from 2 to 6 nm. Chemically pure ferrihydrite rarely occurs in the soil; it usually contains oxyanion (SiO14 4-, PO4 3-) and cation (Al3+) admixtures. Aluminum replace Fe3+ in the structure with a decrease in the mineral particle size. Oxyanions slow down polymerization of Fe3+ aquahydroxomonomers due to the films at the surface of mineral nanoparticles. Si- and Al-ferrihydrites are more resistant to the reductive dissolution than the chemically pure ferrihydrite. In addition, natural ferrihydrite contains organic substance that decreases the grain size of the mineral. External organic ligands favor ferrihydrite dissolution. In the European part of Russia, ferrihydrite is more widespread in the forest soils than in the steppe soils. Poorly crystallized nanoparticles of ferrihydrite adsorb different cations (Zn, Cu) and anions (phosphate, uranyl, arsenate) to immobilize them in soils; therefore, ferrihydrite nanoparticles play a significant role in the biogeochemical cycle of iron and other elements.

  19. Estimation of soil permeability

    Directory of Open Access Journals (Sweden)

    Amr F. Elhakim

    2016-09-01

    Full Text Available Soils are permeable materials because of the existence of interconnected voids that allow the flow of fluids when a difference in energy head exists. A good knowledge of soil permeability is needed for estimating the quantity of seepage under dams and dewatering to facilitate underground construction. Soil permeability, also termed hydraulic conductivity, is measured using several methods that include constant and falling head laboratory tests on intact or reconstituted specimens. Alternatively, permeability may be measured in the field using insitu borehole permeability testing (e.g. [2], and field pumping tests. A less attractive method is to empirically deduce the coefficient of permeability from the results of simple laboratory tests such as the grain size distribution. Otherwise, soil permeability has been assessed from the cone/piezocone penetration tests (e.g. [13,14]. In this paper, the coefficient of permeability was measured using field falling head at different depths. Furthermore, the field coefficient of permeability was measured using pumping tests at the same site. The measured permeability values are compared to the values empirically deduced from the cone penetration test for the same location. Likewise, the coefficients of permeability are empirically obtained using correlations based on the index soil properties of the tested sand for comparison with the measured values.

  20. Engineering Properties of Expansive Soil

    Institute of Scientific and Technical Information of China (English)

    DAI Shaobin; SONG Minghai; HUANG Jun

    2005-01-01

    The components of expansive soil were analyzed with EDAX, and it is shown that the main contents of expansive soil in the northern Hubei have some significant effects on engineering properties of expansive soil. Furthermore, the soil modified by lime has an obvious increase of Ca2+ and an improvement of connections between granules so as to reduce the expansibility and contractility of soil. And it also has a better effect on the modified expansive soil than the one modified by pulverized fuel ash.

  1. Soil biogeochemistry, plant physiology and phytoremediation of cadmium contaminated soils

    Science.gov (United States)

    Cadmium (Cd) loading in soil and the environment has been accelerated worldwide due to enhanced industrialization and intensified agricultural production, particularly in the developing countries. Soil Cd pollution, resulting from both anthropogenic and geogenic sources, has posed an increasing chal...

  2. Water repellent soils: the case for unsaturated soil mechanics

    Directory of Open Access Journals (Sweden)

    Beckett Christopher

    2016-01-01

    Full Text Available Water repellent (or “hydrophobic” or “non-wetting” soils have been studied by soil scientists for well over a century. These soils are typified by poor water infiltration, which leads to increased soil erosion and poor crop growth. However, the importance of water repellence on determining soil properties is now becoming recognised by geotechnical engineers. Water repellent soils may, for example, offer novel solutions for the design of cover systems overlying municipal or mine waste storage facilities. However, investigations into factors affecting their mechanical properties have only recently been initiated. This purpose of this paper is to introduce geotechnical engineers to the concept of water repellent soils and to discuss how their properties can be evaluated under an unsaturated soils framework. Scenarios in which water repellent properties might be relevant in geotechnical applications are presented and methods to quantify these properties in the laboratory and in the field examined.

  3. Validation of numeric methods for calculating interactions between district heating pipelines and the surrounding soil; Validierung numerischer Verfahren zur Berechnung des Interaktionsverhaltens 'Fernwaermeleitung - Baugrund'

    Energy Technology Data Exchange (ETDEWEB)

    Salveter, G.

    2000-07-01

    In this thesis, the results of experimental research work on global bearing behaviour with respect to the existing theoretical basis are systematically analysed for the evaluation and interpretation of measuring results. Among other things, the geometry of the pipeline route, the compactness of the backfilling material and the temperature dependence are considered. The mutual influence of friction and bedding resistances in the region of bends could not yet be determined for a local analysis by existing numerical models. This requires the determination of the induced stress distribution on the pipe perimeter due to lateral displacement of the pipe. The influence is therefore described by a numerical consideration of relative displacements between the pipe and the surrounding soil. Ultimately, relative displacements are verified on the basis of our own complementary results from experimental research carried out in a laboratory for soil mechanics with specially designed test equipment. The global analysis of bearing loads and displacements is done with a numerical model, in which the plastic jacked pipe is idealized as a beam, and the effect of the soil is idealized by spring elements with non-linear force displacement characteristics. An existing numerical model is extended with regard to the new findings and while taking vertical displacements into account. It is used for numerical simulations of selected tests on the global bearing behaviour of underground district heating pipelines which were carried out as part of the research cooperation project. Apart from a good correspondence between calculated results and test results this also provides a plausible description of interrelations. At the same time, however, it also makes itclear that further research is necessary. This thesis provides a contribution to the validation of recent methods for the calculated modelling of the interaction between a district heating pipeline and the subsoil on the basis of

  4. Stress transmission in soil

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Schjønning, Per

    We urgently need increased quantitative knowledge on stress transmission in real soils loaded with agricultural machinery. 3D measurements of vertical stresses under tracked wheels were performed in situ in a Stagnic Luvisol (clay content 20 %) continuously cropped with small grain cereals......). Seven load cells were inserted horizontally from a pit with minimal disturbance of soil in each of three depths (0.3, 0.6 and 0.9 m), covering the width of the wheeled area. The position of the wheel relative to the transducers was recorded using a laser sensor. Finally, the vertical stresses near...... the soil-tyre interface were measured in separate tests by 17 stress transducers across the width of the tyres. The results showed that the inflation pressure controlled the level of maximum stresses at 0.3 m depth, while the wheel load was correlated to the measured stresses at 0.9 m depth. This supports...

  5. Fixation of Soil Using PEC and Separation of Fixed Soil

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Suk; Yang, Hee-Man; Lee, Kune Woo; Seo, Bum-Kyoung; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Radioactive cesium (Cs-137) is the most apprehensive element due to its long half-lives, high solubility in water, and strong radiation emission in the form of gamma rays. Because the radioactivity is localized within topsoil, soil surface on topsoil should be fixed to prevent the spreading of the contaminated soils by wind and water erosion. Many methods have been developing for soil fixation to remove radioactive contaminants in soil and prevent to diffuse radioactive materials. Various materials have been used as fixatives such as clays, molecular sieves, polymer, and petroleum based products. One of the methods is a soil fixation or solidification using polyelectrolyte. Polyelectrolytes have many ionic groups and form the polyelectrolyte complex (PEC) due to electrostatic interaction of anion and cation in an aqueous solution. polyelectrolyte complex can fix soil particles by flocculation and formation of crust between soil. The method can prevent a spread of radioactive material by floating on a soil surface. The decontamination efficiency of the surface soils reached about 90%, and dust release was effectively suppressed during the removal of surface soils. However it has a problem that the removed soil must separate soil and polymer to treat as the waste. In this study, the fixation of soil by polyelectrolyte complex to suppress the spread of contaminant and the separation method of soil and polymer was investigated. The properties of polyelectrolyte complex solution and the stability of fixed soil by polyelectrolyte complex were investigated. The concentration of salt in the polyelectrolyte complex solution is a very important parameter for the soil fixation.

  6. Structural stability of soil crusts. Consequences for soil erodibility assessment

    OpenAIRE

    Darboux, Frédéric; Le Bissonnais, Yves

    2006-01-01

    Erosion and sediment transport processes depend on the soil surface properties. Because of water flow and other processes (climate, agricultural practices, biological activity, etc.), the properties of the soil surface can undergo significant changes that affect erosion. As a consequence, understanding of the transport processes and improvement in soil erosion prediction involve a better assessment of soil surface characteristics. Structural stability has been used to evaluate the sensitivity...

  7. Roles of soil biota and biodiversity in soil environment – A concise communication

    OpenAIRE

    Suleiman Usman; Yakubu Muhammad; Alhaji Chiroman

    2016-01-01

    Soil biota (the living organisms in soil) plays an important role in soil development and soil formation. They are the most important component of soil organic matter decomposition and behave efficiently in the development and formation of soil structure and soil aggregate. Their biodiversity provides many functional services to soil and soil components. They help in dissolving verities of plant and animal materials, which could left as decayed organic matter at the surface soil. Understandin...

  8. Soils in Schools: Embedding Soil Science in STEM

    Science.gov (United States)

    Bryce, Alisa

    2015-01-01

    Soil science, though relevant to a variety of subjects including science, geography, mathematics, social sciences and history, is typically perceived as a subgenre of agriculture. With a global need for soil scientists, and declining numbers in university soil courses, there's a growing gap between science needs and providers. One way to promote…

  9. An alternative to soil taxonomy for describing key soil characteristics

    Science.gov (United States)

    Duniway, Michael C.; Miller, Mark E.; Brown, Joel R.; Toevs, Gordon

    2013-01-01

    We are pleased to see the letter by Schimel and Chadwick (Front Ecol Environ 2013; 11[8]: 405–06), highlighting the importance of soil characterization in ecological and biogeochemical research and explaining the value of soil taxonomy, and we agree with the authors that reporting soil

  10. Dependence of sand soil compressibility on soil physical properties

    Institute of Scientific and Technical Information of China (English)

    I.S.Vakhrin; G.P.Kuzmin

    2014-01-01

    A relationship between soil physical properties and its compressibility has been analyzed. The formulae to determine soil density and porosity have been substantiated in compression tests. The regularity of changes in compressibility of thawed sand soils with various degrees of water content has been experimentally identified.

  11. Allegheny County Soil Type Areas

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains soil type and soil classification, by area. Additional info at: http://mcdc.cas.psu.edu/datawiz.htm;...

  12. World's soils are under threat

    Science.gov (United States)

    Montanarella, Luca; Pennock, Daniel Jon; McKenzie, Neil; Badraoui, Mohamed; Chude, Victor; Baptista, Isaurinda; Mamo, Tekalign; Yemefack, Martin; Singh Aulakh, Mikha; Yagi, Kazuyuki; Hong, Suk Young; Vijarnsorn, Pisoot; Zhang, Gan-Lin; Arrouays, Dominique; Black, Helaina; Krasilnikov, Pavel; Sobocká, Jaroslava; Alegre, Julio; Henriquez, Carlos Roberto; de Lourdes Mendonça-Santos, Maria; Taboada, Miguel; Espinosa-Victoria, David; AlShankiti, Abdullah; Kazem AlaviPanah, Sayed; El Mustafa Elsheikh, Elsiddig Ahmed; Hempel, Jon; Camps Arbestain, Marta; Nachtergaele, Freddy; Vargas, Ronald

    2016-02-01

    The Intergovernmental Technical Panel on Soils has completed the first State of the World's Soil Resources Report. Globally soil erosion was identified as the gravest threat, leading to deteriorating water quality in developed regions and to lowering of crop yields in many developing regions. We need to increase nitrogen and phosphorus fertilizer use in infertile tropical and semi-tropical soils - the regions where the most food insecurity among us are found - while reducing global use of these products overall. Stores of soil organic carbon are critical in the global carbon balance, and national governments must set specific targets to stabilize or ideally increase soil organic carbon stores. Finally the quality of soil information available for policy formulation must be improved - the regional assessments in the State of the World's Soil Resources Report frequently base their evaluations on studies from the 1990s based on observations made in the 1980s or earlier.

  13. Lunar Soil Particle Separator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Soil Particle Separator (LSPS) is an innovative method to beneficiate soil prior to in-situ resource utilization (ISRU). The LSPS improves ISRU oxygen...

  14. Lunar Soil Particle Separator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Soil Particle Separator (LSPS) is an innovative method to beneficiate soil prior to in-situ resource utilization (ISRU). The LSPS can improve ISRU oxygen...

  15. Soil! Get the Scoop - The Soil Science Society of America's International Year of Soils Campaign

    Science.gov (United States)

    Lindbo, David L.; Hopmans, Jan; Olson, Carolyn; Fisk, Susan; Chapman, Susan; van Es, Harold

    2015-04-01

    Soils are a finite natural resource and are nonrenewable on a human time scale. Soils are the foundation for food, animal feed, fuel and natural fiber production, the supply of clean water, nutrient cycling and a range of ecosystem functions. The area of fertile soils covering the world's surface is limited and increasingly subject to degradation, poor management and loss to urbanization. Increased awareness of the life-supporting functions of soil is called for if this trend is to be reversed and so enable the levels of food production necessary to meet the demands of population levels predicted for 2050. The Soil Science Society of America is coordinating with the Global Soil Partnership and other organizations around the world to celebrate the 2015 International Year of Soils and raise awareness and promote the sustainability of our limited soil resources. We all have a valuable role in communicating vital information on soils, a life sustaining natural resource. Therefore, we will provide resources to learn about soils and help us tell the story of soils. We will promote IYS on social media by sharing our posts from Facebook and Twitter. Additionally SSSA developed 12 monthly themes that reflect the diverse value of soils to our natural environment and society. Each month has information on the theme, a lesson plan, and other outreach activities. All information is available on a dedicated website www.soil.org/IYS. The site will be updated constantly throughout the year.

  16. Bioremediation of Creosote - contaminated Soil

    OpenAIRE

    BYSS, Marius

    2008-01-01

    Bioremediation of creosote-contaminated soil was studied employing the methods of soil microbial biology and using new gas chromatography-mass spectrometry-mass spectrometry analytical approach. The changes of the soil microbial community under the polycyclic aromatic hydrocarbons (PAH) pollution impact were analyzed and described, as well as the changes during the bioremediation experiments. Laboratory-scale bioremediation experiments using the soil microbial community (consisted of bacteria...

  17. Microanalysis of Deformation of Soil

    Science.gov (United States)

    1993-06-24

    load: image analysis. European Train- ing "ourse on Soil Micromorphology , pp.19-33. Winand Staring Centrum. Wageningen. Tovey, N.K. 1991a...Vicrofabric of soils under load: image analysis. International Training Course on Soil Micromorphology , pp.14 3 -157. Agricultural University, Wageningen...mineralogy and microfabric of soiikls and sediments. Proc. 9 Interna- tional Meeting on Soil Micromorphology , Townsville, Australia. In press. Tovey

  18. Report on bioventing of petroleum contaminated soils at 108-3C: Active extraction and passive injection (barometric pumping) of a gaseous nutrient

    Energy Technology Data Exchange (ETDEWEB)

    Kastner, J.R.; Lombard, K.; Radway, J. [and others

    1997-05-01

    A bioventing system was constructed with horizontal extraction wells and vertical injection wells in an area which had previously been excavated and then backfilled. Initial in-situ respiration rates (air addition only) suggest that hydrocarbon degradation may be nutrient limited. The rate of TPH degradation was maximum (0.8-1.2 mg/kg/day) between 10-15 ft (bgs), but dropped to essentially zero 30 ft (bgs) within the contaminated zone (even though previous analysis at this depth indicated a TPH concentration of 3800 ppm). Analysis of the soil at 17 ft showed that NO{sub 3} and PO{sub 4} were below detection limits (0.5 ppm), indicating that nutrient limitation may be occurring. Nitrate levels were highest at 10 ft (bgs), correlating with the highest respiration rates. However, phosphate levels were at/or below detection levels throughout tile site (indicating possible PO{sub 4} limitation). Viable cells increased from 3 x 10{sup 6} cfu/g at 3 ft (bgs) to 1 x 10{sup 7} cfu/g at 10 ft (bgs) and remained relatively constant down to 17 ft. Cell numbers in the control area were significantly lower than in the contaminated zone (4.5 x 10{sup 3}). Gas phase nutrients (triethlyphosphate and nitrous oxide) will be injected to see if the hydrocarbon degradation rate can be increased.

  19. Sensor based soil health assessment

    Science.gov (United States)

    Quantification and assessment of soil health involves determining how well a soil is performing its biological, chemical, and physical functions relative to its inherent potential. Due to high cost, labor requirements, and soil disturbance, traditional laboratory analyses cannot provide high resolut...

  20. Perspectives of Anaerobic Soil Disinfestation

    NARCIS (Netherlands)

    Lamers, J.G.; Runia, W.T.; Molendijk, L.P.G.; Bleeker, P.O.

    2010-01-01

    Biological soil disinfestation is an environmentally friendly method to disinfest soil. From now on we refer to it as anaerobic soil disinfestation (ASD). With ASD a green manure crop (40 t/ha) is homogeneously incorporated into the topsoil (0-30 cm) after which the field is lightly compacted and ir

  1. Mycorrhizas and tropical soil fertility

    NARCIS (Netherlands)

    Cardoso, I.M.; Kuyper, T.W.

    2006-01-01

    Major factors that constrain tropical soil fertility and sustainable agriculture are low nutrient capital, moisture stress, erosion, high P fixation, high acidity with aluminium toxicity, and low soil biodiversity. The fragility of many tropical soils limits food production in annual cropping system

  2. Good soil: a good start

    NARCIS (Netherlands)

    Reuler, van H.; Staps, S.; Vermeulen, G.H.

    2009-01-01

    Soil plays a central role in plant production and the environment. Organic growers depend on the soil’s natural richness and resistance to disease. In order to foster these essential qualities, farmers and researchers are looking at ways to stimulate soil life, optimise soil structure and close nutr

  3. The threat of soil salinity

    NARCIS (Netherlands)

    Daliakopoulos, I.N.; Tsanis, I.K.; Koutroulis, A.; Kourgialas, N.N.; Varouchakis, A.E.; Karatzas, G.P.; Ritsema, C.J.

    2016-01-01

    Soil salinisation is one of the major soil degradation threats occurring in Europe. The effects of salinisation can be observed in numerous vital ecological and non-ecological soil functions. Drivers of salinisation can be detected both in the natural and man-made environment, with climate and th

  4. Nitrification in Dutch heathland soils.

    NARCIS (Netherlands)

    Boer, de W.

    1989-01-01

    This thesis is the result of a study on the production of nitrate in Dutch heathland soils. Most of the heathlands are located on acid, sandy soils. Therefore , it has dealt mainly with the occurrence, nature and mechanisms of nitrification in acid soils. In the Netherlands, the production of nitrat

  5. Engineering Significant of Swelling Soils

    Directory of Open Access Journals (Sweden)

    Behzad Kalantari

    2012-08-01

    Full Text Available This study describes some of the most important swelling characters of expansive soils when used as foundation materials to support various types of civil engineering structures. Expansive soils are considered among difficult foundation materials and expand upon wetting and shrink upon losing moisture. They are considered problematic soils for architectural and civil engineers. These types of soils may cause minor to major structural damages to pavements as well as buildings. It is therefore essential to detect swelling soils from non-problematic foundation soils before any civil engineering projects are constructed over or adjacent to them. The study begins with definition of expansive soils and shows its distributions in the world as well as the basic causes for swelling potential that these type of soils poses. It is also shown that, the most probable depth of expansion to check for possible swelling potential for swelling soils is soil’s active zone. This zone is the most upper depth of expansive soil and it may extend up to 20 ft. (6 m below ground level. The moisture content of soil through active zone varies during different seasons while in lower part of expansive soil the moisture content stays constant during hot and cold season. Among various methods to check for swelling potential, plastic index and liquid limits are two most crucial factors, as these factors tend to increase, the swelling potential increase as well.

  6. Soil threats and soil protection: the role of biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, J. L.

    2009-07-01

    The concept of soil conservation/soil protection in its wider sense has undergone important changes through history. Perceptions of soil as a crucial base of life in ancient cultures progressively evolved to a more pragmatic vision, with close connection to food production for survival. For centuries, agrarian production and the provision of food for humankind remained the main and crucial vision of the interaction of societies with soil. However, there are also some other new and important concepts related to soil which have progressively developed. (Author)

  7. Soil-ecological risks for soil degradation estimation

    Science.gov (United States)

    Trifonova, Tatiana; Shirkin, Leonid; Kust, German; Andreeva, Olga

    2016-04-01

    Soil degradation includes the processes of soil properties and quality worsening, primarily from the point of view of their productivity and decrease of ecosystem services quality. Complete soil cover destruction and/or functioning termination of soil forms of organic life are considered as extreme stages of soil degradation, and for the fragile ecosystems they are normally considered in the network of their desertification, land degradation and droughts /DLDD/ concept. Block-model of ecotoxic effects, generating soil and ecosystem degradation, has been developed as a result of the long-term field and laboratory research of sod-podzol soils, contaminated with waste, containing heavy metals. The model highlights soil degradation mechanisms, caused by direct and indirect impact of ecotoxicants on "phytocenosis- soil" system and their combination, frequently causing synergistic effect. The sequence of occurring changes here can be formalized as a theory of change (succession of interrelated events). Several stages are distinguished here - from heavy metals leaching (releasing) in waste and their migration downward the soil profile to phytoproductivity decrease and certain phytocenosis composition changes. Phytoproductivity decrease leads to the reduction of cellulose content introduced into the soil. The described feedback mechanism acts as a factor of sod-podzolic soil self-purification and stability. It has been shown, that using phytomass productivity index, integrally reflecting the worsening of soil properties complex, it is possible to solve the problems dealing with the dose-reflecting reactions creation and determination of critical levels of load for phytocenosis and corresponding soil-ecological risks. Soil-ecological risk in "phytocenosis- soil" system means probable negative changes and the loss of some ecosystem functions during the transformation process of dead organic substance energy for the new biomass composition. Soil-ecological risks estimation is

  8. Microorganisms as Indicators of Soil Health

    DEFF Research Database (Denmark)

    Nielsen, M. N.; Winding, A.; Binnerup, S.;

    Microorganisms are an essential part of living soil and of outmost importance for soil health. As such they can be used as indicators of soil health. This report reviews the current and potential future use of microbial indicators of soil health and recommends specific microbial indicators for soil...... indicators into soil monitoring programmes as they become applicable....

  9. A soil science renaissance

    NARCIS (Netherlands)

    Hartemink, A.E.

    2008-01-01

    The renaissance was an intellectually-rich period following a period of stasis in the medieval period. Something analogous appears to be currently taking place in soil science where novel approaches to thought are combined with a revival of ideas from the past. Renewed interest in agriculture (food,

  10. Plant–soil feedbacks

    NARCIS (Netherlands)

    Cortois, Roeland; Schröder-Georgi, Thomas; Weigelt, Alexandra; Putten, van der Wim H.; Deyn, De Gerlinde B.

    2016-01-01

    1. Plant–soil feedback (PSF), plant trait and functional group concepts advanced our understanding of plant community dynamics, but how they are interlinked is poorly known.
    2. To test how plant functional groups (FGs: graminoids, small herbs, tall herbs, legumes) and plant traits relate to PSF,

  11. Soil on Phoenix's MECA

    Science.gov (United States)

    2008-01-01

    This image shows soil delivery to NASA's Phoenix Mars Lander's Microscopy, Electrochemistry and Conductivity Analyzer (MECA). The image was taken by the lander's Surface Stereo Imager on the 131st Martian day, or sol, of the mission (Oct. 7, 2008). At the bottom of the image is the chute for delivering samples to MECA's microscopes. It is relatively clean due to the Phoenix team using methods such as sprinkling to minimize cross-contamination of samples. However, the cumulative effect of several sample deliveries can be seen in the soil piles on either side of the chute. On the right side are the four chemistry cells with soil residue piled up on exposed surfaces. The farthest cell has a large pile of material from an area of the Phoenix workspace called 'Stone Soup.' This area is deep in the trough at a polygon boundary, and its soil was so sticky it wouldn't even go through the funnel. One of Phoenix's solar panels is shown in the background of this image. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  12. Infiltration in Unsaturated Soils

    DEFF Research Database (Denmark)

    Ghotbi, Abdoul R.; Omidvar, M.; Barari, Amin

    2011-01-01

    An approximate analytical solution has been established for the well known Richards’ equation for unsaturated flow of transports in soils. Despite the importance of Richards’ equation in geotechnical and geoenvironmental applications, most solutions to the problem are generally based on numerical...

  13. Impact of Soil Texture on Soil Ciliate Communities

    Science.gov (United States)

    Chau, J. F.; Brown, S.; Habtom, E.; Brinson, F.; Epps, M.; Scott, R.

    2014-12-01

    Soil water content and connectivity strongly influence microbial activities in soil, controlling access to nutrients and electron acceptors, and mediating interactions between microbes within and between trophic levels. These interactions occur at or below the pore scale, and are influenced by soil texture and structure, which determine the microscale architecture of soil pores. Soil protozoa are relatively understudied, especially given the strong control they exert on bacterial communities through predation. Here, ciliate communities in soils of contrasting textures were investigated. Two ciliate-specific primer sets targeting the 18S rRNA gene were used to amplify DNA extracted from eight soil samples collected from Sumter National Forest in western South Carolina. Primer sets 121F-384F-1147R (semi-nested) and 315F-959R were used to amplify soil ciliate DNA via polymerase chain reaction (PCR), and the resulting PCR products were analyzed by gel electrophoresis to obtain quantity and band size. Approximately two hundred ciliate 18S rRNA sequences were obtained were obtained from each of two contrasting soils. Sequences were aligned against the NCBI GenBank database for identification, and the taxonomic classification of best-matched sequences was determined. The ultimate goal of the work is to quantify changes in the ciliate community under short-timescale changes in hydrologic conditions for varying soil textures, elucidating dynamic responses to desiccation stress in major soil ciliate taxa.

  14. Soil moisture estimation with limited soil characterization for decision making

    Science.gov (United States)

    Chanzy, A.; Richard, G.; Boizard, H.; Défossez, P.

    2009-04-01

    Many decisions in agriculture are conditional to soil moisture. For instance in wet conditions, farming operations as soil tillage, organic waste spreading or harvesting may lead to degraded results and/or induce soil compaction. The development of a tool that allows the estimation of soil moisture is useful to help farmers to organize their field work in a context where farm size tends to increase as well as the need to optimize the use of expensive equipments. Soil water transfer models simulate soil moisture vertical profile evolution. These models are highly sensitive to site dependant parameters. A method to implement the mechanistic soil water and heat flow model (the TEC model) in a context of limited information (soil texture, climatic data, soil organic carbon) is proposed [Chanzy et al., 2008]. In this method the most sensitive model inputs were considered i.e. soil hydraulic properties, soil moisture profile initialization and the lower boundary conditions. The accuracy was estimated by implementing the method on several experimental cases covering a range of soils. Simulated soil moisture results were compared to soil moisture measurements. The obtained accuracy in surface soil moisture (0-30 cm) was 0.04 m3/m3. When a few soil moisture measurements are available (collected for instance by the farmer using a portable moisture sensor), significant improvement in soil moisture accuracy is obtained by assimilating the results into the model. Two assimilation strategies were compared and led to comparable results: a sequential approach, where the measurement were used to correct the simulated moisture profile when measurements are available and a variational approach which take moisture measurements to invert the TEC model and so retrieve soil hydraulic properties of the surface layer. The assimilation scheme remains however heavy in terms of computing time and so, for operational purposed fast code should be taken to simulate the soil moisture as with the

  15. Degradation kinetics of ptaquiloside in soil and soil solution

    DEFF Research Database (Denmark)

    Ovesen, Rikke Gleerup; Rasmussen, Lars Holm; Hansen, Hans Christian Bruun

    2008-01-01

    Ptaquiloside (PTA) is a carcinogenic norsesquiterpene glycoside produced in bracken (Pteridium aquilinum (L.) Kuhn), a widespread, aggressive weed. Transfer of PTA to soil and soil solution eventually may contaminate groundwater and surface water. Degradation rates of PTA were quantified in soil...... and soil solutions in sandy and clayey soils subjected to high natural PTA loads from bracken stands. Degradation kinetics in moist soil could be fitted with the sum of a fast and a slow first-order reaction; the fast reaction contributed 20 to 50% of the total degradation of PTA. The fast reaction....... Experiments with sterile controls confirmed that nonmicrobial degradation processes constituted more than 90% of the fast degradation and 50% of the slow degradation. The lower nonmicrobial degradation rate observed in the clayey compared with the sandy soil is attributed to a stabilizing effect of PTA...

  16. Soil compaction: Evaluation of stress transmission and resulting soil structure

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Schjønning, Per; Keller, Thomas;

    and compaction-resulted soil structure at the same time. Stress transmission was quantified using both X-ray CT and Tactilus sensor mat, and soil-pore structure was quantified using X-ray CT. Our results imply that stress transmission through soil highly depends on the magnitude of applied load and aggregate......, as a result stress transmission mode was shifted from discrete towards more like a continuum. Continuum-like stress transmission mode was better simulated with Boussinesq (1885) model based on theory of elasticity compared to discrete. The soil-pore structure was greatly affected by increasing applied......Accurate estimation of stress transmission and resultant deformation in soil profiles is a prerequisite for the development of predictive models and decision support tools for preventing soil compaction. Numerous studies have been carried out on the effects of soil compaction, whilst relatively few...

  17. Soil physics: a Moroccan perspective

    Science.gov (United States)

    Lahlou, Sabah; Mrabet, Rachid; Ouadia, Mohamed

    2004-06-01

    Research on environmental pollution and degradation of soil and water resources is now of highest priority worldwide. To address these problems, soil physics should be conceived as a central core to this research. This paper objectives are to: (1) address the role and importance of soil physics, (2) demonstrate progress in this discipline, and (3) present various uses of soil physics in research, environment and industry. The study of dynamic processes at and within the soil vadose zone (flow, dispersion, transport, sedimentation, etc.), and ephemeral phenomena (deformation, compaction, etc.), form an area of particular interest in soil physics. Soil physics has changed considerably over time. These changes are due to needed precision in data collection for accurate interpretation of space and time variation of soil properties. Soil physics interacts with other disciplines and sciences such as hydro(geo)logy, agronomy, environment, micro-meteorology, pedology, mathematics, physics, water sciences, etc. These interactions prompted the emergence of advanced theories and comprehensive mechanisms of most natural processes, development of new mathematical tools (modeling and computer simulation, fractals, geostatistics, transformations), creation of high precision instrumentation (computer assisted, less time constraint, increased number of measured parameters) and the scale sharpening of physical measurements which ranges from micro to watershed. The environment industry has contributed to an enlargement of many facets of soil physics. In other words, research demand in soil physics has increased considerably to satisfy specific and environmental problems (contamination of water resources, global warming, etc.). Soil physics research is still at an embryonic stage in Morocco. Consequently, soil physicists can take advantage of developments occurring overseas, and need to build up a database of soil static and dynamic properties and to revise developed models to meet

  18. How does soil management affect carbon losses from soils?

    Science.gov (United States)

    Klik, A.; Trümper, G.

    2009-04-01

    Agricultural soils are a major source as well as a sink of organic carbon (OC). Amount and distribution of OC within the soil and within the landscape are driven by land management but also by erosion and deposition processes. At the other hand the type of soil management influences mineralization and atmospheric carbon dioxide losses by soil respiration. In a long-term field experiment the impacts of soil tillage systems on soil erosion processes were investigated. Following treatments were compared: 1) conventional tillage (CT), 2) conservation tillage with cover crop during the winter period (CS), and 3) no-till with cover crop during winter period (NT). The studies were carried out at three sites in the Eastern part of Austria with annual precipitation amounts from 650 to 900 mm. The soil texture ranged from silt loam to loam. Since 2007 soil CO2 emissions are measured with a portable soil respiration system in intervals of about one week, but also in relation to management events. Concurrent soil temperature and soil water content are measured and soil samples are taken for chemical and microbiological analyses. An overall 14-yr. average soil loss between 1.0 t.ha-1.yr-1 for NT and 6.1 t.ha-1.yr-1 for CT resulted in on-site OC losses from 18 to 79 kg ha-1.yr-1. The measurements of the carbon dioxide emissions from the different treatments indicate a high spatial variation even within one plot. Referred to CT plots calculated carbon losses amounted to 65-94% for NT plots while for the different RT plots they ranged between 84 and 128%. Nevertheless site specific considerations have to be taken into account. Preliminary results show that the adaptation of reduced or no-till management strategies has enormous potential in reducing organic carbon losses from agricultural used soils.

  19. Bioavailability of radiocaesium in soil: parameterization using soil characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Syssoeva, A.A.; Konopleva, I.V. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation)

    2004-07-01

    It has been shown that radiocaesium availability to plants strongly influenced by soil properties. For the best evaluation of TFs it necessary to use mechanistic models that predict radionuclide uptake by plants based on consideration of sorption-desorption and fixation-remobilization of the radionuclide in the soil as well as root uptake processes controlled by the plant. The aim of the research was to characterise typical Russian soils on the basis of the radiocaesium availability. The parameter of the radiocaesium availability in soils (A) has been developed which consist on radiocaesium exchangeability; CF -concentration factor which is the ratio of the radiocaesium in plant to that in soil solution; K{sub Dex} - exchangeable solid-liquid distribution coefficient of radiocaesium. The approach was tested for a wide range of Russian soils using radiocaesium uptake data from a barley pot trial and parameters of the radiocaesium bioavailability. Soils were collected from the arable horizons in different soil climatic zones of Russia and artificially contaminated by {sup 137}Cs. The classification of soils in terms of the radiocaesium availability corresponds quite well to observed linear relationship between {sup 137}Cs TF for barley and A. K{sub Dex} is related to the soil radiocaesium interception potential (RIP), which was found to be positively and strongly related to clay and physical clay (<0,01 mm) content. The {sup 137}Cs exchangeability were found to be in close relation to the soil vermiculite content, which was estimated by the method of Cs{sup +} fixation. It's shown radiocaesium availability to plants in soils under study can be parameterized through mineralogical soil characteristics: % clay and the soil vermiculite content. (author)

  20. The Choice on Soil Compaction Test Methods and Analysis of the Results%浅谈土击实试验方法的选择和结果分析

    Institute of Scientific and Technical Information of China (English)

    莫树光; 王玉玲

    2015-01-01

    The soil compaction test is identified the backfill foundation soil compaction, effectively control project quality, to provide rolling compaction test data for the engineering construction site. This paper introduced how to choose a different compaction test method according to demand or different construction methods and the test results of heavy compaction test and the light compaction test are analyzed,and finally the laws were proposed:①the soil plasticity index is inversely proportional to the maximum dry density, and is proportional with the optimum moisture content; ② the optimum water content of pure clay or soil with few sands is almost equal to the plastic limit moisture content in the light compact test.%土的击实试验是了解回填地基土的压实情况,有效地控制工程质量,为工程施工现场碾压提供压实性资料的试验,是确保回填土质量的重要技术指标。本文介绍了可依据工程实际情况或不同施工方法选择不同的击实试验方法,通过对重型击实试验和轻型击实试验的试验结果进行数据分析,提出了土的塑性指数与最大干密度成反比,与最优含水率成正比,质纯的粘土或含砂量少的粘性土的轻型击实试验最优含水率与土的塑限含水率基本相等的规律。

  1. [Effects of nitrogen fertilization, soil moisture and soil temperature on soil respiration during summer fallow season].

    Science.gov (United States)

    Zhang, Fang; Guo, Sheng-Li; Zou, Jun-Liang; Li, Ze; Zhang, Yan-Jun

    2011-11-01

    On the loess plateau, summer fallow season is a hot rainy time with intensive soil microbe activities. To evaluate the response of soil respiration to soil moisture, temperature, and N fertilization during this period is helpful for a deep understanding about the temporal and spatial variability of soil respiration and its impact factors, then a field experiment was conducted in the Changwu State Key Agro-Ecological Experimental Station, Shaanxi, China. The experiment included five N application rates: unfertilized 0 (N0), 45 (N45), 90 (N90), 135(N135), and 180 (N180) kg x hm(-2). The results showed that at the fallow stage, soil respiration rate significantly enhanced from 1.24 to 1.91 micromol x (m2 x s)(-1) and the average of soil respiration during this period [6.20 g x (m2 x d)(-1)] was close to the growing season [6.95 g x (m2 x d)(-1)]. The bivariate model of soil respiration with soil water and soil temperature was better than the single-variable model, but not so well as the three-factor model when explaining the actual changes of soil respiration. Nitrogen fertilization alone accounted for 8% of the variation soil respiration. Unlike the single-variable model, the results could provide crucial information for further research of multiple factors on soil respiration and its simulation.

  2. Evaluation-of soil enzyme activities as soil quality indicators in sludge-amended soils.

    Science.gov (United States)

    Dindar, Efsun; Şağban, Fatma Olcay Topaç; Başkaya, Hüseyin Savaş

    2015-07-01

    Soil enzymatic activities are commonly used as biomarkers of soil quality. Several organic and inorganic compounds found in municipal wastewater sludges can possibly be used as fertilizers. Monitoring and evaluating the quality of sludge amended soils with enzyme activities accepted as a beneficial practice with respect to sustainable soil management. In the present study, variation of some enzyme activities (Alkaline phosphatase, dehydrogenase, urease and beta-glucosidase activities) in soils amended with municipal wastewater sludge at different application rates (50, 100 and 200 t ha(-1) dry sludge) was evaluated. Air dried sludge samples were applied to soil pots and sludge-soil mixtures were incubated during a period of three months at 28 degrees C. The results of the study showed that municipal wastewater sludge amendment apparently increased urease, dehydrogenase, alkaline phosphatase and P-glucosidase activities in soil by 48-70%, 14-47%, 33-66% and 9-14%, respectively. The maximum activity was generally observed in sludge amended soil with dose of 200 t ha(-1). Urease activity appeared to be a better indicator of soil enhancement with wastewater sludge, as its activity was more strongly increased by sludge amendment. Accordingly, urease activity is suggested to be soil quality indicator best suited for measuring existing conditions and potential changes in sludge-amended soil.

  3. Soil Architecture and physicochemical functions

    DEFF Research Database (Denmark)

    de Jonge, Lis Wollesen; Møldrup, Per; Vendelboe, Anders Lindblad

    2012-01-01

    Soils function as Earth's life support system, a thin layer full of life covering most of the terrestrial surfaces. Soils form the foundation of society. Norman Borlaug stated in his Nobel laureate lecture that “the first essential component of social justice is adequate food for all mankind...... research community, including the need for enhanced public awareness of the soil's essential life-support functions, putting value on soil ecosystem services (“capital of soil”), and design of optimal soil-based growth media for long-term missions in space....

  4. Soil biodiversity and human health

    Science.gov (United States)

    Wall, Diana H.; Nielsen, Uffe N.; Six, Johan

    2015-12-01

    Soil biodiversity is increasingly recognized as providing benefits to human health because it can suppress disease-causing soil organisms and provide clean air, water and food. Poor land-management practices and environmental change are, however, affecting belowground communities globally, and the resulting declines in soil biodiversity reduce and impair these benefits. Importantly, current research indicates that soil biodiversity can be maintained and partially restored if managed sustainably. Promoting the ecological complexity and robustness of soil biodiversity through improved management practices represents an underutilized resource with the ability to improve human health.

  5. Estimating soil moisture and soil thermal and hydraulic properties by assimilating soil temperatures using a particle batch smoother

    Science.gov (United States)

    Dong, Jianzhi; Steele-Dunne, Susan C.; Ochsner, Tyson E.; Giesen, Nick van de

    2016-05-01

    This study investigates the potential of estimating the soil moisture profile and the soil thermal and hydraulic properties by assimilating soil temperature at shallow depths using a particle batch smoother (PBS) using synthetic tests. Soil hydraulic properties influence the redistribution of soil moisture within the soil profile. Soil moisture, in turn, influences the soil thermal properties and surface energy balance through evaporation, and hence the soil heat transfer. Synthetic experiments were used to test the hypothesis that assimilating soil temperature observations could lead to improved estimates of soil hydraulic properties. We also compared different data assimilation strategies to investigate the added value of jointly estimating soil thermal and hydraulic properties in soil moisture profile estimation. Results show that both soil thermal and hydraulic properties can be estimated using shallow soil temperatures. Jointly updating soil hydraulic properties and soil states yields robust and accurate soil moisture estimates. Further improvement is observed when soil thermal properties were also estimated together with the soil hydraulic properties and soil states. Finally, we show that the inclusion of a tuning factor to prevent rapid fluctuations of parameter estimation, yields improved soil moisture, temperature, and thermal and hydraulic properties.

  6. Understanding and Enhancing Soil Biological Health: The Solution for Reversing Soil Degradation

    OpenAIRE

    R Michael Lehman; Cynthia A. Cambardella; Diane E. Stott; Veronica Acosta-Martinez; Manter, Daniel K.; Jeffrey S. Buyer; Jude E. Maul; Smith, Jeffrey L.; Harold P. Collins; Jonathan J. Halvorson; Kremer, Robert J.; Jonathan G. Lundgren; Tom F. Ducey; Jin, Virginia L.; Douglas L. Karlen

    2015-01-01

    Our objective is to provide an optimistic strategy for reversing soil degradation by increasing public and private research efforts to understand the role of soil biology, particularly microbiology, on the health of our world’s soils. We begin by defining soil quality/soil health (which we consider to be interchangeable terms), characterizing healthy soil resources, and relating the significance of soil health to agroecosystems and their functions. We examine how soil biology influences soil ...

  7. Spatial and temporal variability of soil electrical conductivity related to soil moisture

    OpenAIRE

    José Paulo Molin; Gustavo Di Chiacchio Faulin

    2013-01-01

    Soil electrical conductivity (ECa) is a soil quality indicator associated to attributes interesting to site-specific soil management such as soil moisture and texture. Soil ECa provides information that helps guide soil management decisions, so we performed spatial evaluation of soil moisture in two experimental fields in two consecutive years and modeled its influence on soil ECa. Soil ECa, moisture and clay content were evaluated by statistical, geostatistical and regression analyses. Semiv...

  8. Soil organic matter and soil biodiversity spots in urban and semi urban soils of southeast Mexico

    Science.gov (United States)

    Huerta, Esperanza

    2015-04-01

    We have observed how the constant use of compost or vermicompost has created spots of soil restoration in urban and semiurban soils of Chiapas (Huitepec and Teopisca), increasing soil organic matter amount, soil moisture and soil porosity, and enhancing then the presence of soil biodiversity; for example, in a Milpa with vermicompost (polyculture of Zea mays with Curcubita pepo, and Fasolius vulgaris) we have found a high density of an epigeic earthworm (640 ind.m2), Dichogaster bolahui, not present in the same type of soil just some meters of distance, in an Oak forest, where soil macroinvertebrates abundance decreased drastically. In another ecosystem within a Persea Americana culture, we found how above and below ground soil biodiversity is affected by the use of vermicompost, having clearly different microcosmos with and without vermicompost (30-50% more micro and macro invertebrates with vermicompost). So now in Campeche, within those soils that are classified by the mayas as tzequel, soils not use for agriculture, we have implemented home gardens and school gardens by the use of compost of vermicomposts in urban and semiurban soils. In school gardens (mainly primary schools) students have cultivated several plants with alimentary purposes; teachers have observed how the increase of soil biodiversity by the use of compost or vermicompost has enhanced the curiosity of children, even has promoted a more friendly behavior among students, they have learned how to do compost and how to apply it. Urban and semiurban soils can be modified by the use of compost and vermicompost, and soil biodiversity has extremely increased.

  9. Discovering the essence of soil

    Science.gov (United States)

    Frink, D.

    2012-04-01

    Science, and what it can learn, is constrained by its paradigms and premises. Similarly, teaching and what topics can be addressed are constrained by the paradigms and premises of the subject matter. Modern soil science is founded on the five-factor model of Dokuchaev and Jenny. Combined with Retallack's universal definition of soil as geologic detritus affected by weathering and/or biology, modern soil science emphasizes a descriptive rather than an interpretive approach. Modern soil science however, emerged from the study of plants and the need to improve crop yields in the face of chronic and wide spread famine in Europe. In order to teach that dirt is fascinating we must first see soils in their own right, understand their behavior and expand soil science towards an interpretive approach rather than limited as a descriptive one. Following the advice of James Hutton given over two centuries ago, I look at soils from a physiological perspective. Digestive processes are mechanical and chemical weathering, the resulting constituents reformed into new soil constituents (e.g. clay and humus), translocated to different regions of the soil body to serve other physiological processes (e.g. lamellae, argillic and stone-line horizons), or eliminated as wastes (e.g. leachates and evolved gasses). Respiration is described by the ongoing and diurnal exchange of gasses between the soil and its environment. Circulatory processes are evident in soil pore space, drainage capacity and capillary capability. Reproduction of soil is evident at two different scales: the growth of clay crystals (with their capacity for mutation) and repair of disturbed areas such as result from the various pedo-perturbations. The interactions between biotic and abiotic soil components provide examples of both neurological and endocrine systems in soil physiology. Through this change in perspective, both biotic and abiotic soil processes become evident, providing insight into the possible behavior of

  10. Soil biodiversity and soil community composition determine ecosystem multifunctionality.

    Science.gov (United States)

    Wagg, Cameron; Bender, S Franz; Widmer, Franco; van der Heijden, Marcel G A

    2014-04-08

    Biodiversity loss has become a global concern as evidence accumulates that it will negatively affect ecosystem services on which society depends. So far, most studies have focused on the ecological consequences of above-ground biodiversity loss; yet a large part of Earth's biodiversity is literally hidden below ground. Whether reductions of biodiversity in soil communities below ground have consequences for the overall performance of an ecosystem remains unresolved. It is important to investigate this in view of recent observations that soil biodiversity is declining and that soil communities are changing upon land use intensification. We established soil communities differing in composition and diversity and tested their impact on eight ecosystem functions in model grassland communities. We show that soil biodiversity loss and simplification of soil community composition impair multiple ecosystem functions, including plant diversity, decomposition, nutrient retention, and nutrient cycling. The average response of all measured ecosystem functions (ecosystem multifunctionality) exhibited a strong positive linear relationship to indicators of soil biodiversity, suggesting that soil community composition is a key factor in regulating ecosystem functioning. Our results indicate that changes in soil communities and the loss of soil biodiversity threaten ecosystem multifunctionality and sustainability.

  11. Chelant soil-washing technology for metal-contaminated soil.

    Science.gov (United States)

    Voglar, David; Lestan, Domen

    2014-01-01

    We demonstrate here, in a pilot-scale experiment, the feasibility of ethylenediaminetetraacetate (EDTA)based washing technology for soils contaminated with potentially toxic metals. Acid precipitation coupled to initial alkaline toxic metal removal and an electrochemical advanced oxidation process were used for average recovery of 76 +/- 2% of EDTA per batch and total recycle of water in a closed process loop. No waste water was generated; solid wastes were efficiently bitumen-stabilized before disposal. The technology embodiment, using conventional process equipment, such as a mixer for soil extraction, screen for soil/gravel separation, filter chamber presses for soil/liquid and recycled EDTA separation and soil rinsing, continuous centrifuge separator for removal of precipitated metals and electrolytic cells for process water cleansing, removed up to 72%, 25% and 66% of Pb, Zn and Cd from garden soil contaminated with up to 6960, 3797 and 32.6 mg kg(-1) of Pb, Zn and Cd, respectively, in nine 60kg soil batches. Concentrations of Pb and Zn remaining in the remediated soil and bioaccessible from the simulated human intestinal phase soil were reduced by 97% and 96% and were brought under the level of determination for Cd. In the most cost-effective operation mode, the material and energy costs of remediation amounted to 50.5 Euros ton(-1) soil and the total cost to 299 Euros ton(-1).

  12. Hydrophobicity of soil samples and soil size fractions

    Energy Technology Data Exchange (ETDEWEB)

    Lowen, H.A.; Dudas, M.J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Renewable Resources; Roy, J.L. [Imperial Oil Resources Canada, Calgary, AB (Canada); Johnson, R.L. [Alberta Research Council, Vegreville, AB (Canada); McGill, W.B. [Alberta Univ., Edmonton, AB (Canada). Dept. of Renewable Resources

    2001-07-01

    The inability of dry soil to absorb water droplets within 10 seconds or less is defined as soil hydrophobicity. The severity, persistence and circumstances causing it vary greatly. There is a possibility that hydrophobicity in Alberta is a symptom of crude oil spills. In this study, the authors investigated the severity of soil hydrophobicity, as determined by the molarity of ethanol droplet test (MED) and dichloromethane extractable organic (DEO) concentration. The soil samples were collected from pedons within 12 hydrophobic soil sites, located northeast from Calgary to Cold Lake, Alberta. All the sites were located at an elevation ranging from 450 metres to 990 metres above sea level. The samples contained compounds from the Chernozemic, Gleysolic, Luvisolic, and Solonetzic soil orders. The results obtained indicated that the MED and DEO were positively correlated in whole soil samples. No relationships were found between MED and DEO in soil samples divided in soil fractions. More severe hydrophobicity and lower DEO concentrations were exhibited in clay- and silt-sized particles in the less than 53 micrometres, when compared to the samples in the other fraction (between 53 and 2000 micrometres). It was concluded that hydrophobicity was not restricted to a particular soil particle size class. 5 refs., 4 figs.

  13. Soil phosphorus landscape models for precision soil conservation.

    Science.gov (United States)

    Hong, Jinseok; Grunwald, Sabine; Vasques, Gustavo M

    2015-05-01

    Phosphorus (P) enrichment in soils has been documented in the Santa Fe River watershed (SFRW, 3585 km) in north-central Florida. Yet the environmental factors that control P distribution in soils across the landscape, with potential contribution to water quality impairment, are not well understood. The main goal of this study was to develop soil-landscape P models to support a "precision soil conservation" approach combining fine-scale (i.e., site-specific) and coarse-scale (i.e., watershed-extent) assessment of soil P. The specific objectives were to: (i) identify those environmental properties that impart the most control on the spatial distribution of soil Mehlich-1 extracted P (MP) in the SFRW; (ii) model the spatial patterns of soil MP using geostatistical methods; and (iii) assess model quality using independent validation samples. Soil MP data at 137 sites were fused with spatially explicit environmental covariates to develop soil MP prediction models using univariate (lognormal kriging, LNK) and multivariate methods (regression kriging, RK, and cokriging, CK). Incorporation of exhaustive environmental data into multivariate models (RK and CK) improved the prediction of soil MP in the SFRW compared with the univariate model (LNK), which relies solely on soil measurements. Among all tested environmental covariates, land use and vegetation related properties (topsoil) and geologic data (subsoil) showed the largest predictive power to build inferential models for soil MP. Findings from this study contribute to a better understanding of spatially explicit interactions between soil P and other environmental variables, facilitating improved land resource management while minimizing adverse risks to the environment.

  14. SoilEffects - start characterization of the experimental soil

    DEFF Research Database (Denmark)

    Løes, Anne-Kristin; Johansen, Anders; Pommeresche, Reidun

    Summary This report describes the establishment, experimental plan and initial soil characteristics of the field experiment linked to the project “Effects of anaerobically digested manure on soil fertility - establishment of a long-term study under Norwegian conditions” (SoilEffects, 2010......-14). The aim of the SoilEffects project is to identify potential risks and benefits for soil fertility when animal manure is anaerobically digested for biogas production. The field experiment was established on Tingvoll research farm in 2011. A biogas plant was built at this farm in 2010, to digest the manure...... from a herd of about 25 organically managed dairy cows. This report describes the initial characterization of the soil biology, chemistry and physics, along with the background of the project, the selection process of the research field and the project design. Effects of the manure treatment...

  15. Pedotransfer functions estimating soil hydraulic properties using different soil parameters

    DEFF Research Database (Denmark)

    Børgesen, Christen Duus; Iversen, Bo Vangsø; Jacobsen, Ole Hørbye;

    2008-01-01

    Estimates of soil hydraulic properties using pedotransfer functions (PTF) are useful in many studies such as hydrochemical modelling and soil mapping. The objective of this study was to calibrate and test parametric PTFs that predict soil water retention and unsaturated hydraulic conductivity...... parameters. The PTFs are based on neural networks and the Bootstrap method using different sets of predictors and predict the van Genuchten/Mualem parameters. A Danish soil data set (152 horizons) dominated by sandy and sandy loamy soils was used in the development of PTFs to predict the Mualem hydraulic...... of the hydraulic properties of the studied soils. We found that introducing measured water content as a predictor generally gave lower errors for water retention predictions and higher errors for conductivity predictions. The best of the developed PTFs for predicting hydraulic conductivity was tested against PTFs...

  16. Electrokinetic remediation of unsaturated soils

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, E.R.; Kozak, M.W. (Sandia National Labs., Albuquerque, NM (United States)); Mattson, E.D. (SAT-UNSAT, Inc., Albuquerque, NM (United States))

    1992-01-01

    Heavy-metal contamination of soil and groundwater is a widespread problem in the DOE weapons complex, and for the nation as a whole electrokinetic remediation is one possible technique for in situ removal of such contaminants from unsaturated soils. Large spills and leaks can contaminate both the soil above the water table as well as the aquifer itself. Electrodes are implanted in the soil, and a direct current is imposed between the electrodes. The application of direct current leads to a number of effects: ionic species and charged particles in the soil water will migrate to the oppositely charged electrode (electromigration and electrophoresis), and concomitant with this migration, a bulk flow of water is induced, usually toward the cathode (electroosmosis). The combination of these phenomena leads to a movement of contaminants toward the electrodes. The direction of contaminant movement will be determined by a number of factors, among which are type and concentration of contaminant, soil type and structure, interfacial chemistry of the soil-water system, and the current density in the soil pore water. Contaminants arriving at the electrodes may potentially be removed from the soil by one of several methods, such as electroplating or adsorption onto the electrode, precipitation or co-precipitation at the electrode, pumping of water near the electrode, or complexing with ion-exchange resins. Experimental results are described on the removal of sodium dichromate and food dye from soil.

  17. A Handbook on Artificial Soils for Indoor Photovoltaic Soiling Tests

    Energy Technology Data Exchange (ETDEWEB)

    Burton, Patrick D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); King, Bruce Hardison [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-10-01

    This manuscript is intended to serve as a practical guide to conducting repeatable indoor soiling experiments for PV applications. An outline of techniques, materials and equipment used in prior studies [1-3] is presented. Additional recommendations and practical guidance has been presented. Major sections include techniques to formulate soil simulants, ('standard grime') and feedstocks from traceable components, spray application, and quantitative measurement methodologies at heavy and minimal soil loadings.

  18. Soil Moisture Data Assimilation in Soil Water Flow Modeling

    Science.gov (United States)

    Pachepsky, Y. A.; Guber, A.; Jacques, D.; Pan, F.; van Genuchten, M.; Cady, R. E.; Nicholson, T. J.

    2010-12-01

    Soil water flow modeling has multiple applications. This modeling is based on simplifications stemming from both conceptual uncertainty and lack of detailed knowledge about parameters. Modern soil moisture sensors can provide detailed information about changes in soil water content in time and with depth. This information can be used for data assimilation in soil water flow modeling. The ensemble Kalman filter appears to be an appropriate method for that. Earlier we demonstrated ensemble simulations of soil water flow by using sets of pedotransfer functions (empirical relationships between soil hydraulic properties and soil basic properties, such as particle size distribution, bulk density, organic carbon content, etc.). The objective of this work was to apply the data assimilation with the ensemble Kalman filter to soil water flow modeling, using soil water content monitoring with TDR probes and an ensemble of soil water flow models parameterized with different pedotransfer functions. Experiments were carried out at the Bekkevoort site, Belgium. Sixty time domain reflectometry (TDR) probes with two rods) were installed along the trench in loamy soil at 12 locations with 50-cm horizontal spacing at five depths (15, 35, 55, 75, and 95 cm). Water content and weather parameters were monitored for one year with 15 min frequency. Soil water flow was simulated using the HYDRUS6 software. Mean daily means of water contents at the observation depths were the measurements used in data assimilation. Eighteen pedotransfer functions for water retention and one for hydraulic conductivity were applied to generate ensembles to evaluate the uncertainty in simulation results, whereas the replicated measurements at each of measurement depths were used to characterize the uncertainty in data. Data assimilation appeared to be very efficient. Even assimilating measurements at a single depth provided substantial improvement in simulations at other observation depths. Results on

  19. Soil-water interaction in unsaturated expansive soil slopes

    Institute of Scientific and Technical Information of China (English)

    ZHAN Liangtong

    2007-01-01

    The intensive soil-water interaction in unsatura- ted expansive soil is one of the major reasons for slope fail- ures. In this paper, the soil-water interaction is investigated with the full-scale field inspection of rainwater infiltration and comprehensive experiments, including wetting-induced softening tests, swelling, and shrinkage tests. It is demonstrat- ed that the soil-water interaction induced by seasonal wetting- drying cycles is very complex, and it involves coupled effects among the changes in water content, suction, stress, deforma- tion and shear strength. In addition, the abundant cracks in the expansive soil play an important role in the soil-water interaction. The cracks disintegrate the soil mass, and more importantly, provide easy pathways for rainfall infiltration. Infiltration of rainwater not only results in wetting-induced softening of the shallow unsaturated soil layers, but also leads to the increase of horizontal stress. The increase of horizontal stress may lead to a local passive failure. The seasonal wetting-drying cycles tend to result in a down-slope creeping of the shallow soil layer, which leads to progressive slope failure.

  20. The effect of intrinsic soil properties on soil quality assessments

    Directory of Open Access Journals (Sweden)

    Alessandro Samuel-Rosa

    2013-10-01

    Full Text Available The assessment of soil quality is based on indicators and indices derived from soil properties. However, intrinsic soil properties may interfere with other soil properties that vary under different land uses and are used to calculate the indices. The aim of this study was to assess the extent to which intrinsic soil properties (clay and iron oxide contents explain variable soil properties (sum of bases, potential acidity, organic carbon, total porosity, and bulk density under different land uses (native forest, no-tillage and conventional agriculture on small family farms in Southern Brazil. The results showed that the five properties evaluated can be included in soil quality assessments and are not influenced by the clay and iron oxide contents. It was concluded that for little weathered 1:1 and 2:1 phyllosilicate rich-soils, if the difference between the maximum and the minimum clay content under the different land uses is less than about 200 g kg-1 and the iron oxide content less than about 15 g kg-1, the physico-chemical soil properties in the surface layer are determined mostly by the land use.

  1. Soil organic carbon distribution in roadside soils of Singapore.

    Science.gov (United States)

    Ghosh, Subhadip; Scharenbroch, Bryant C; Ow, Lai Fern

    2016-12-01

    Soil is the largest pool of organic carbon in terrestrial systems and plays a key role in carbon cycle. Global population living in urban areas are increasing substantially; however, the effects of urbanization on soil carbon storage and distribution are largely unknown. Here, we characterized the soil organic carbon (SOC) in roadside soils across the city-state of Singapore. We tested three hypotheses that SOC contents (concentration and density) in Singapore would be positively related to aboveground tree biomass, soil microbial biomass and land-use patterns. Overall mean SOC concentrations and densities (0-100 cm) of Singapore's roadside soils were 29 g kg(-1) (4-106 g kg(-1)) and 11 kg m(-2) (1.1-42.5 kg m(-2)) with median values of 26 g kg(-1) and 10 kg m(-2), respectively. There was significantly higher concentration of organic carbon (10.3 g kg(-1)) in the top 0-30 cm soil depth compared to the deeper (30-50 cm, and 50-100 cm) soil depths. Singapore's roadside soils represent 4% of Singapore's land, but store 2.9 million Mg C (estimated range of 0.3-11 million Mg C). This amount of SOC is equivalent to 25% of annual anthropogenic C emissions in Singapore. Soil organic C contents in Singapore's soils were not related to aboveground vegetation or soil microbial biomass, whereas land-use patterns to best explain variance in SOC in Singapore's roadside soils. We found SOC in Singapore's roadside soils to be inversely related to urbanization. We conclude that high SOC in Singapore roadside soils are probably due to management, such as specifications of high quality top-soil, high use of irrigation and fertilization and also due to an optimal climate promoting rapid growth and biological activity.

  2. Stochastic Modeling of Soil Salinity

    CERN Document Server

    Suweis, S; Van der Zee, S E A T M; Daly, E; Maritan, A; Porporato, A; 10.1029/2010GL042495

    2012-01-01

    A minimalist stochastic model of primary soil salinity is proposed, in which the rate of soil salinization is determined by the balance between dry and wet salt deposition and the intermittent leaching events caused by rainfall events. The long term probability density functions of salt mass and concentration are found by reducing the coupled soil moisture and salt mass balance equation to a single stochastic differential equation driven by multiplicative Poisson noise. The novel analytical solutions provide insight on the interplay of the main soil, plant and climate parameters responsible for long-term soil salinization. In particular, they show the existence of two distinct regimes, one where the mean salt mass remains nearly constant (or decreases) with increasing rainfall frequency, and another where mean salt content increases markedly with increasing rainfall frequency. As a result, relatively small reductions of rainfall in drier climates may entail dramatic shifts in long-term soil salinization trend...

  3. Applications of visual soil evaluation

    DEFF Research Database (Denmark)

    Ball, Bruce C; Munkholm, Lars Juhl; Batey, Tom

    2013-01-01

    assessment, to encourage their wider use and to foster international cooperation. The previous main meeting of the group in 2005 at Peronne, France, brought together, for the first time, a group of soil scientists who had each developed a method to evaluate soil structure directly in the field (Boizard et al......., 2006). Ten visual and tactile methods were used to assess soil structure on the same soil. This stimulated significant ongoing cooperation between participants and several authors have since modified and developed their procedures (Mueller et al., 2009 and Shepherd, 2009). Cooperation also led...... to the re-development of the Peerlkamp numeric method of assessment of soil structure into the Visual Evaluation of Soil Structure (VESS) spade test (Ball et al., 2007 and Guimarães et al., 2011). The meeting also recommended further cooperation between members of the Working Group. The evaluation...

  4. Dependence of soil respiration on soil temperature and soil moisture in successional forests in Southern China

    Science.gov (United States)

    Tang, X.-L.; Zhou, G.-Y.; Liu, S.-G.; Zhang, D.-Q.; Liu, S.-Z.; Li, J.; Zhou, C.-Y.

    2006-01-01

    The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (?? SD) soil respiration rate in the DNR forests was (9.0 ?? 4.6) Mg CO2-C/hm2per year, ranging from (6.1 ?? 3.2) Mg CO2-C/hm2per year in early successional forests to (10.7 ?? 4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities. ?? 2006 Institute of Botany, Chinese Academy of

  5. Dependence of Soil Respiration on Soil Temperature and Soil Moisture in Successional Forests in Southern China

    Institute of Scientific and Technical Information of China (English)

    Xu-Li Tang; Guo-Yi Zhou; Shu-Guang Liu; De-Qiang Zhang; Shi-Zhong Liu; Jiong Li; Cun-Yu Zhou

    2006-01-01

    The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (± SD) soil respiration rate in the DNR forests was (9.0±4.6) Mg CO2-C/hm2 per year, ranging from (6.1±3.2) Mg CO2-C/hm2 per year in early successional forests to (10.7±4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities.

  6. Acoustic behaviors of unsaturated soils

    Science.gov (United States)

    Lu, Z.

    2011-12-01

    Soils are unconsolidated granular materials, consisting of solid particles, water and air. Their mechanical and dynamic behaviors are determined by the discrete nature of the media as well as external and inter-particle forces. For unsaturated soils, two factors significantly affect soils acoustic/seismic responses: external pressure and internal water potential/matric suction. In triaxial cell tests, unsaturated soils were subjected to predefined stress paths to undergo stages of normal consolidation, unload-reload cycles, and failure. The stress deformation curve and stress-P-wave velocity were measured and compared. The study revealed that soil's dynamic response to external pressure are similar to those of the load-deformation behaviors and demonstrated that acoustic velocity can be used to monitor the state of stress of soils. In a long term field soil survey, the P-wave velocities were found to be correlated with water potential as expressed as a power-law relationship. The above phenomena can be understood by using the Terzaghi' s the principle of effective stress. The measured results were in good agreement with Brutsaert theory. The effective stress concept can also be applied to explain the observations in a soil pipe flow study in which soil internal erosion processes were monitored and interpreted by the temporal evolution of the P-wave velocity. In addition to above linear acoustic behaviors, soils, like other earth materials, exhibit astonishing non-classical nonlinear behaviors such as end-point memory, hysteresis, strain -dependent shear modulus, resonant frequency shift, and phase shift, harmonics generation, etc. A nonlinear acoustic study of a soil as a function of water content showed that the nonlinear acoustic parameter are much sensitive to the variations of soil water content than that of the acoustic velocity.

  7. Soil Behavior Under Blast Loading

    Science.gov (United States)

    2010-12-01

    Chen, W.F. and Baladi, G.Y. (1985), Soil plasticity : Theory and Implementation, Elsevier, Amsterdam, The Netherlands. Cui, Y.J. and...is a simple cone in principal stress space as shown in FIG. 2-9. Both Mohr-Coulomb model and Drucker-Prager model capture soil ... plasticity behavior very well and ensure a unique solution. However, these perfectly-plastic soil models have inherent limitations and shortcomings: (1

  8. Soil vulnerability for cesium transfer.

    Science.gov (United States)

    Vandenhove, Hildegarde; Sweeck, Lieve

    2011-07-01

    The recent events at the Fukushima Daiichi nuclear power plant in Japan have raised questions about the accumulation of radionuclides in soils and the possible impacts on agriculture surrounding nuclear power plants. This article summarizes the knowledge gained after the nuclear power plant accident in Chernobyl, Ukraine, on how soil parameters influence soil vulnerability for radiocesium bioavailability, discusses some potential agrochemical countermeasures, and presents some predictions of radiocesium crop concentrations for areas affected by the Fukushima accident.

  9. Vital soil; function, value and properties

    NARCIS (Netherlands)

    Doelman, P.; Eijsackers, H.J.P.

    2004-01-01

    Healthy soil, with active soil life, deters long-term soil degradation and ensures that geo-physical processes are undisturbed. Is the vitality of soil under threat due to human civilization? Or is it due to contamination, intensification, and deforestation? Vital Soil aims to look at the effects so

  10. Guidelines for soil description, 4th edition

    NARCIS (Netherlands)

    Jahn, R.; Blume, H.P.; Asio, V.B.; Spaargaren, O.; Schad, P.

    2006-01-01

    Soils are affected by human activities, such as industrial, municipal and agriculture, that often result in soil degradation and loss. In order to prevent soil degradation and to rehabilitate the potentials of degraded soils, reliable soil data are the most important prerequisites for the design of

  11. ICRAF-ISRIC Soil VNIR Spectral Library

    NARCIS (Netherlands)

    Batjes, N.H.

    2014-01-01

    The ICRAF-ISRIC Soil VNIR Spectral Library contains visible near infrared spectra of 4,438 soils selected from the Soil Information System (ISIS) of the International Soil Reference and Information Centre (ISRIC). The samples consist of all physically archived samples at ISRIC in 2004 for which soil

  12. Monitor Soil Degradation or Triage for Soil Security? An Australian Challenge

    OpenAIRE

    Andrea Koch; Adrian Chappell; Michael Eyres; Edward Scott

    2015-01-01

    The Australian National Soil Research, Development and Extension Strategy identifies soil security as a foundation for the current and future productivity and profitability of Australian agriculture. Current agricultural production is attenuated by soil degradation. Future production is highly dependent on the condition of Australian soils. Soil degradation in Australia is dominated in its areal extent by soil erosion. We reiterate the use of soil erosion as a reliable indicator of soil condi...

  13. Two-Dimensional Porosity of Crusted Silty Soils: Indicators of Soil Quality in Semiarid Rangelands?

    OpenAIRE

    2011-01-01

    Little is known about the morphological characteristics of pores in soil crusts. The objective was to characterize the 2D-porosity (amount, shape, size and area of pores) of soil crusts to ascertain their potential as indicators of soil quality for natural crusted soils. 2D-porosity was described in thin sections and measured by image analysis of polished resin-impregnated soil blocks. Physical soil crust and incipient biological soil crusts appear to be the lowest-quality soil...

  14. Indicators for Monitoring Soil Biodiversity

    DEFF Research Database (Denmark)

    Bispo, A.; Cluzeau, D.; Creamer, R.

    2009-01-01

    is made for a set of suitable indicators for monitoring the decline in soil biodiversity (Bispo et al. 2007). These indicators were selected both from a literature review and an inventory of national monitoring programmes. Decline in soil biodiversity was defined as the reduction of forms of life living...... indicators are actually measured.   For monitoring application it was considered in ENVASSO that only three key indicators per soil stress were practical. For indicating biodiversity decline it was difficult to arrive at a small set of indicators due to the complexity of soil biota and functions. Therefore...

  15. Frost Heave in Colloidal Soils

    KAUST Repository

    Peppin, Stephen

    2011-01-01

    We develop a mathematical model of frost heave in colloidal soils. The theory accountsfor heave and consolidation while not requiring a frozen fringe assumption. Two solidificationregimes occur: a compaction regime in which the soil consolidates to accommodate the ice lenses, and a heave regime during which liquid is sucked into the consolidated soil from an external reservoir, and the added volume causes the soil to heave. The ice fraction is found to vary inversely with thefreezing velocity V , while the rate of heave is independent of V , consistent with field and laboratoryobservations. © 2011 Society for Industrial and Applied Mathematics.

  16. Puerto Rico Soil Erodibility (Kffact)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Puerto Rico soil erodibility (Kffactor) - low values indicate low vulnerability to erosion, higher values mean higher susceptibility to runoff.

  17. Experimental analysis of passive earth pressure against rigid retaining wall under translation mode for finite soils%有限土体刚性挡墙平动模式被动土压力试验研究

    Institute of Scientific and Technical Information of China (English)

    应宏伟; 张金红; 王小刚; 李冰河; 朱伟

    2016-01-01

    It is inappropriate to calculate the earth pressure for finite soils using the classical Coulomb or Rankine earth pressure theory. A series of laboratory model tests with different widths of backfill are conducted for the passive case of a rigid retaining wall subjected to horizontal translation. The change in lateral earth pressure distribution from the at-rest condition to the passive condition is monitored by using a set of pressure cells. The particle image velocimetry technique is employed to observe the development of a failure zone in the soils. The experiment results show that there is a good agreement between the measured earth pressures and the Coulomb’s solution in the case of infinite soils. However, the passive earth pressures on the moving retaining wall for finite soils are much more than the Coulomb’s solution. With the decrease of the soil width, the limited displacement of the wall under passive state seems to increase, and the passive earth pressures also increase significantly when the heights of the application points of the resultant earth pressure move down gradually. Moreover, with the decrease of the soil width, the heave of the backfill surface increases gradually, the inclination angles of the slip surface increase slightly, and the lateral earth pressures on the fixed boundary also increase gradually.%经典的库仑或朗肯土压力理论无法适用有限土体情况下的土压力问题。利用研制的土压力试验模型装置,进行了一组不同填土宽度的刚性挡墙平动模式室内模型试验,采用微型土压力盒量测从静止状态到被动极限状态的水平土压力分布的变化,利用颗粒图像测速技术研究土体内滑裂面发展规律。试验结果表明:半无限土体情况下的被动土压力大小、分布和合力作用点与库仑被动土压力较为接近。而有限宽度情况下移动挡墙上各深度的被动土压力值均大于库仑被动土压力,且土体宽度

  18. Adopting soil organic carbon management practices in soils of varying quality

    NARCIS (Netherlands)

    Merante, Paolo; Dibari, Camilla; Ferrise, Roberto; Sánchez, Berta; Iglesias, Ana; Lesschen, Jan Peter; Kuikman, Peter; Yeluripati, Jagadeesh; Smith, Pete; Bindi, Marco

    2017-01-01

    Soil organic carbon (SOC) content can greatly affect soil quality by determining and maintaining important soil physical conditions, properties and soil functions. Management practices that maintain or enhance SOC affect soil quality and may favour the capacity of soils to sequester further organ

  19. SOIL moisture data intercomparison

    Science.gov (United States)

    Kerr, Yann; Rodriguez-Frenandez, Nemesio; Al-Yaari, Amen; Parens, Marie; Molero, Beatriz; Mahmoodi, Ali; Mialon, Arnaud; Richaume, Philippe; Bindlish, Rajat; Mecklenburg, Susanne; Wigneron, Jean-Pierre

    2016-04-01

    The Soil Moisture and Ocean Salinity satellite (SMOS) was launched in November 2009 and started delivering data in January 2010. Subsequently, the satellite has been in operation for over 6 years while the retrieval algorithms from Level 1 to Level 2 underwent significant evolutions as knowledge improved. Other approaches for retrieval at Level 2 over land were also investigated while Level 3 and 4 were initiated. In this présentation these improvements are assessed by inter-comparisons of the current Level 2 (V620) against the previous version (V551) and new products either using neural networks or Level 3. In addition a global evaluation of different SMOS soil moisture (SM) products is performed comparing products with those of model simulations and other satellites (AMSR E/ AMSR2 and ASCAT). Finally, all products were evaluated against in situ measurements of soil moisture (SM). The study demonstrated that the V620 shows a significant improvement (including those at level1 improving level2)) with respect to the earlier version V551. Results also show that neural network based approaches can yield excellent results over areas where other products are poor. Finally, global comparison indicates that SMOS behaves very well when compared to other sensors/approaches and gives consistent results over all surfaces from very dry (African Sahel, Arizona), to wet (tropical rain forests). RFI (Radio Frequency Interference) is still an issue even though detection has been greatly improved while RFI sources in several areas of the world are significantly reduced. When compared to other satellite products, the analysis shows that SMOS achieves its expected goals and is globally consistent over different eco climate regions from low to high latitudes and throughout the seasons.

  20. Solos urbanos Urban soils

    Directory of Open Access Journals (Sweden)

    Fabrício de Araújo Pedron

    2004-10-01

    Full Text Available A forte pressão provocada pela expansão urbana desordenada sobre os recursos naturais, principalmente os solos, tem provocado danos, muitas vezes de difícil reparo. A grande concentração populacional em centros urbanos cada vez maiores tem dirigido a atenção de diferentes profissionais para o recurso solo, no sentido de entender sua dinâmica para minimizar sua degradação. No entanto, a falta de conhecimento sobre as propriedades, bem como sobre a aptidão dos solos sob uso urbano tem provocado o seu mau uso, resultando em processos como compactação, erosão, deslizamentos e inundações, assim como poluição com substâncias orgânicas, inorgânicas e patógenos, aumentando os custos do desenvolvimento afetando toda a sociedade. Neste sentido, este texto discute como o conhecimento pedológico pode diminuir os efeitos negativos provocados pelo processo de urbanização.The strong pressure caused by the disordered urban expansion over the natural resources, mainly the soils, has caused damages, many times difficult to repair. The great population concentration in urban centers getting larger and larger has been driving the attention of different professionals to soil resource, in the sense of understanding its dynamics to minimize its degradation. The lack of knowledge related to the soils properties and capability promote their inappropriate use, resultig in degrading processes as compaction, erosion, sliding, floods, and organic, inorganic and patogenic pollution, increasing the cost of development and affecting the whole society. This text discusses how pedologic knowledge can reduce the negative effects caused by the urbanization process.

  1. Modelling soil organic carbon concentration of mineral soils in arable lands using legacy soil data

    DEFF Research Database (Denmark)

    Suuster, E; Ritz, Christian; Roostalu, H

    2012-01-01

    Soil organic carbon (SOC) concentration is an essential factor in biomass production and soil functioning. SOC concentration values are often obtained by prediction but the prediction accuracy depends much on the method used. Currently, there is a lack of evidence in the soil science literature...... as to the advantages and shortcomings of the different commonly used prediction methods. Therefore, we compared and evaluated the merits of the median approach, analysis of covariance, mixed models and random forests in the context of prediction of SOC concentrations of mineral soils under arable management in the A......-horizon. Three soil properties were used in all of the developed models: soil type, physical clay content (particle size

  2. Soil on Phoenix's TEGA

    Science.gov (United States)

    2008-01-01

    This image shows soil on the doors of the Thermal and Evolved Gas Analyzer (TEGA) onboard NASA's Phoenix Mars Lander. The image was taken by the lander's Robotic Arm Camera on the 131st Martian day, or sol, of the mission (Oct. 7, 2008). This sample delivered to TEGA was named 'Rosy Red.' The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  3. Online Soil Science Lesson 3: Soil Forming Factors

    Science.gov (United States)

    This lesson explores the five major factors of soil formation, namely: 1) climate; 2) organisms; 3) time; 4) topography; and 5) parent material and their influence in forming soil. The distinction between active and passive factors, moisture and temperature regimes, organism and topographic influen...

  4. Desert soil collection at the JPL soil science laboratory

    Science.gov (United States)

    Blank, G. B.; Cameron, R. E.

    1969-01-01

    Collection contains desert soils and other geologic materials collected from sites in the United States and foreign countries. Soils are useful for test purposes in research related to extraterrestrial life detection, sampling, harsh environmental studies, and determining suitable areas for training astronauts for lunar exploration.

  5. Soil water balance scenario studies using predicted soil hydraulic parameters

    NARCIS (Netherlands)

    Nemes, A.; Wösten, J.H.M.; Bouma, J.; Várallyay, G.

    2006-01-01

    Pedotransfer functions (PTFs) have become a topic drawing increasing interest within the field of soil and environmental research because they can provide important soil physical data at relatively low cost. Few studies, however, explore which contributions PTFs can make to land-use planning, in ter

  6. Soil Spectroscopy: An Alternative to Wet Chemistry for Soil Monitoring

    DEFF Research Database (Denmark)

    Nocita, M.; Stevens, A.; van Wesemael, Bas

    2015-01-01

    constraining the application of soil spectroscopy as an alternative to traditional laboratory analyses, together with the limits of the technique, are addressed. The paper also highlights that the widespread use of spectroscopy to monitor the status of the soil should be encouraged by (1) the creation...

  7. Biological soil crusts as soil stabilizers: Chapter 16

    Science.gov (United States)

    Belnap, Jayne; Buedel, Burkhard; Weber, Bettina; Buedel, Burkhard; Belnap, Jayne

    2016-01-01

    Soil erosion is of particular concern in dryland regions, as the sparse cover of vascular plants results in large interspaces unprotected from the erosive forces of wind and water. Thus, most of these soil surfaces are stabilized by physical or biological soil crusts. However, as drylands are extensively used by humans and their animals, these crusts are often disturbed, compromising their stabilizing abilities. As a result, approximately 17.5% of the global terrestrial lands are currently being degraded by wind and water erosion. All components of biocrusts stabilize soils, including green algae, cyanobacteria, fungi, lichens, and bryophytes, and as the biomass of these organisms increases, so does soil stability. In addition, as lichens and bryophytes live atop the soil surface, they provide added protection from raindrop impact that cyanobacteria and fungi, living within the soil, cannot. Much research is still needed to determine the relative ability of individual species and suites of species to stabilize soils. We also need a better understanding of why some individuals or combination of species are better than others, especially as these organisms become more frequently used in restoration efforts.

  8. Underestimation of boreal soil carbon stocks by mathematical soil carbon models linked to soil nutrient status

    Science.gov (United States)

    Ťupek, Boris; Ortiz, Carina A.; Hashimoto, Shoji; Stendahl, Johan; Dahlgren, Jonas; Karltun, Erik; Lehtonen, Aleksi

    2016-08-01

    Inaccurate estimate of the largest terrestrial carbon pool, soil organic carbon (SOC) stock, is the major source of uncertainty in simulating feedback of climate warming on ecosystem-atmosphere carbon dioxide exchange by process-based ecosystem and soil carbon models. Although the models need to simplify complex environmental processes of soil carbon sequestration, in a large mosaic of environments a missing key driver could lead to a modeling bias in predictions of SOC stock change.We aimed to evaluate SOC stock estimates of process-based models (Yasso07, Q, and CENTURY soil sub-model v4) against a massive Swedish forest soil inventory data set (3230 samples) organized by a recursive partitioning method into distinct soil groups with underlying SOC stock development linked to physicochemical conditions.For two-thirds of measurements all models predicted accurate SOC stock levels regardless of the detail of input data, e.g., whether they ignored or included soil properties. However, in fertile sites with high N deposition, high cation exchange capacity, or moderately increased soil water content, Yasso07 and Q models underestimated SOC stocks. In comparison to Yasso07 and Q, accounting for the site-specific soil characteristics (e. g. clay content and topsoil mineral N) by CENTURY improved SOC stock estimates for sites with high clay content, but not for sites with high N deposition.Our analysis suggested that the soils with poorly predicted SOC stocks, as characterized by the high nutrient status and well-sorted parent material, indeed have had other predominant drivers of SOC stabilization lacking in the models, presumably the mycorrhizal organic uptake and organo-mineral stabilization processes. Our results imply that the role of soil nutrient status as regulator of organic matter mineralization has to be re-evaluated, since correct SOC stocks are decisive for predicting future SOC change and soil CO2 efflux.

  9. Chemical evaluation of soil-solution in acid forest soils

    Science.gov (United States)

    Lawrence, G.B.; David, M.B.

    1996-01-01

    Soil-solution chemistry is commonly studied in forests through the use of soil lysimeters.This approach is impractical for regional survey studies, however, because lysimeter installation and operation is expensive and time consuming. To address these problems, a new technique was developed to compare soil-solution chemistry among red spruce stands in New York, Vermont, New Hampshire, Maine. Soil solutions were expelled by positive air pressure from soil that had been placed in a sealed cylinder. Before the air pressure was applied, a solution chemically similar to throughfall was added to the soil to bring it to approximate field capacity. After the solution sample was expelled, the soil was removed from the cylinder and chemically analyzed. The method was tested with homogenized Oa and Bs horizon soils collected from a red spruce stand in the Adirondack Mountains of New York, a red spruce stand in east-central Vermont, and a mixed hardwood stand in the Catskill Mountains of New York. Reproducibility, effects of varying the reaction time between adding throughfall and expelling soil solution (5-65 minutes) and effects of varying the chemical composition of added throughfall, were evaluated. In general, results showed that (i) the method was reproducible (coefficients of variation were generally reaction-time did not affect expelled solution concentrations, and (iii) adding and expelling solution did not cause detectable changes in soil exchange chemistry. Concentrations of expelled solutions varied with the concentrations of added throughfall; the lower the CEC, the more sensitive expelled solution concentrations were to the chemical concentrations of added throughfall. Addition of a tracer (NaBr) showed that the expelled solution was a mixture of added solution and solution that preexisted in the soil. Comparisons of expelled solution concentrations with concentrations of soil solutions collected by zero-tension and tension lysimetry indicated that expelled

  10. Evaluation of soil structure in the framework of an overall soil quality rating

    DEFF Research Database (Denmark)

    Mueller, L; Shepherd, T G; Schindler, U;

    2013-01-01

    Soil structure is an important aspect of agricultural soil quality, and its preservation and improvement are key to sustaining soil functions. Methods of overall soil quality assessment which include visual soil structure information can be useful tools for monitoring and managing the global soil...... resource. The aim of the paper is: (i) to demonstrate the role of visual quantification of soil structure within the procedure of the overall soil quality assessment by the Muencheberg Soil Quality Rating (M-SQR), (ii) to quantify the magnitude and variability of soil structure and overall M......-SQR on a number of agricultural research sites and (iii) to analyse the correlations of soil quality rating results with crop yields. We analysed visual soil structure and overall soil quality on a range of 20 experimental sites in seven countries. To assess visual soil structure we utilised the Visual Soil...

  11. Anthropogenic effects on soil micromycetes

    Directory of Open Access Journals (Sweden)

    Đukić Dragutin A.

    2007-01-01

    Full Text Available This paper is a synthesis of long-term investigations based on the effect of different authropogenic pollutants (mineral and organic fertilizers, heavy metals, contaminated irrigation water, nitrification inhibitor and detergents on the dynamics of soil fungi number. The investigations were performed at the Microbiology Department and trial fields of the Faculty of Agronomy in Čačak on smonitza and alluvium soils in field and under greenhouse conditions. Maize, wheat, barley and red clover were used as test plants in these studies. The quantitative composition of the fungi in the soils investigated was determined by the Čapek selective agar dilution method. The study results show that the number of soil fungi was dependent on the type and rate of agrochemicals used, on the growing season, and the soil zone the samples were taken from for the analysis. Lower nitrogen fertiliser rates (80 and 120 kg x ha-1 and organic fertilizers stimulated the development of soil fungi, unlike the rate of 150 kg x ha-1. Heavy metals, mercury and cadmium in particular, as well as high rates of the N-serve nitrification inhibitor, inhibited the development of this group of soil microorganisms. Generally, the adverse effect of contaminated irrigation water on the soil fungi was recorded in both soil types, and particularly in the smonitza under red clover. Low detergent (Meril concentrations did not have any significant effect on this group of microorganisms. In this respect, it can be concluded that the soil fungi number dynamics can be used in monitoring soils polluted by different toxinogenic substances.

  12. ANTHROPOGENIC EFFECTS ON SOIL MICROMYCETES

    Directory of Open Access Journals (Sweden)

    Dragutin A. Đukić

    2007-09-01

    Full Text Available This paper is a synthesis of long-term investigations based on the effect of different (mineral and organic fertilisers, heavy metals, contaminated irrigation water, nitrification inhibitor and detergents on the dynamics of soil fungi number. The investigations were performed at the Microbiology Department and trial fields of the Faculty of Agronomy in Cacak on smonitza and alluvium soils in field and greenhouse conditions. Maize, wheat, barley and red clover were used as test plants in these studies. The quantitative composition of the fungi in the soils investigated was determined by the Czapek selective agar dilution method. The study results show that the number of soil fungi was dependent on the type and rate of agrochemicals used, on the growing season and the soil zone the samples were taken from for the analysis. Lower nitrogen fertiliser rates (80 and 120 kg?ha-1 and organic fertilisers stimulated the development of soil fungi, unlike the rate of 150 kg?ha- 1. Heavy metals, mercury and cadmium in particular, as well as high rates of the N-serve nitrification inhibitor inhibited the development of this group of soil microorganisms. Generally, the adverse effect of contaminated irrigation water on the soil fungi was recorded in both soil types, and particularly in the smonitza under red clover. Low detergent (Meril concentrations did not have any significant effect on this group of microorganisms. In this respect, it can be concluded that the soil fungi number dynamics can be used in monitoring soils polluted by different toxinogenic substances.

  13. Soil fungi as indicators of pesticide soil pollution

    Directory of Open Access Journals (Sweden)

    Mandić Leka

    2005-01-01

    Full Text Available Soil fungi, with their pronounced enzymic activity and high osmotic potential, represent a significant indicator of negative effects of different pesticides on the agroecosystem as a whole. In that respect, a trial was set up on the alluvium soil type with the aim to investigate the effect of different herbicides (Simazine, Napropamid, Paraquat, fungicides (Captan and Mancozeb and insecticides (Fenitrothion and Dimethoate on a number of soil fungi under apple trees. The number of soil fungi was determined during four growing seasons by an indirect method of dilution addition on the Czapek agar. The study results indicate that the fungi belong to the group of microorganisms that, after an initial sensible response to the presence of pesticides in the soil, very rapidly establish normal metabolism enabling them even to increase their number. The fungicides and insecticides applied were found to be particularly effective in that respect.

  14. Thermal stability of soils and detectability of intrinsic soil features

    Science.gov (United States)

    Siewert, Christian; Kucerik, Jiri

    2014-05-01

    Soils are products of long term pedogenesis in ecosystems. They are characterized by a complex network of interactions between organic and inorganic constituents, which influence soil properties and functions. However, the interrelations cannot easily be determined. Our search for unifying principles of soil formation focuses on water binding. This approach was derived from water-dependent soil formation. It considers the importance of water binding in theories about the origin of genes, in the structural arrangement and functionality of proteins, and in the co-evolution of organism species and the biosphere during the history of earth. We used thermogravimetry as a primary experimental technique. It allows a simple determi-nation of bound water together with organic and inorganic components in whole soil samples without a special preparation. The primary goal was to search for fingerprinting patterns using dynamics of thermal mass losses (TML) caused by water vaporization from natural soils, as a reference base for soil changes under land use. 301 soil samples were collected in biosphere reserves, national parks and other areas as-sumingly untouched by human activity in Siberia, North and South America, Antarctica, and in several long term agricultural experiments. The results did not support the traditional data evaluation procedures used in classical differ-ential thermogravimetry. For example, peak positions and amplitudes did not provide useful information. In contrast, using thermal mass losses (TML) in prefixed smaller, e.g. 10 °C temperature intervals allowed the determination of the content of carbon, clay, nitrogen and carbonates with high accuracy. However, this approach was applicable for soils and neither for soil-like carbon containing mineral substrates without pedogenetic origin, nor for plant residues or soils containing ashes, cinder, or charcoal. Therefore, intrinsic soil regulation processes are discussed as a possible factor causing

  15. [Soil Microbial Respiration Under Different Soil Temperature Conditions and Its Relationship to Soil Dissolved Organic Carbon and Invertase].

    Science.gov (United States)

    Wu, Jing; Chen, Shu-tao; Hu, Zheng-hua; Zhang, Xu

    2015-04-01

    In order to investigate the soil microbial respiration under different temperature conditions and its relationship to soil dissolved organic carbon ( DOC) and invertase, an indoor incubation experiment was performed. The soil samples used for the experiment were taken from Laoshan, Zijinshan, and Baohuashan. The responses of soil microbial respiration to the increasing temperature were studied. The soil DOC content and invertase activity were also measured at the end of incubation. Results showed that relationships between cumulative microbial respiration of different soils and soil temperature could be explained by exponential functions, which had P values lower than 0.001. The coefficient of temperature sensitivity (Q10 value) varied from 1.762 to 1.895. The Q10 value of cumulative microbial respiration decreased with the increase of soil temperature for all soils. The Q10 value of microbial respiration on 27 days after incubation was close to that of 1 day after incubation, indicating that the temperature sensitivity of recalcitrant organic carbon may be similar to that of labile organic carbon. For all soils, a highly significant ( P = 0.003 ) linear relationship between cumulative soil microbial respiration and soil DOC content could be observed. Soil DOC content could explain 31.6% variances of cumulative soil microbial respiration. For the individual soil and all soils, the relationship between cumulative soil microbial respiration and invertase activity could be explained by a highly significant (P soil microbial respiration.

  16. KBRA OPWP Soil Depth to Water

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The...

  17. Biogeochemistry: Soil carbon in a beer can

    Science.gov (United States)

    Davidson, Eric A.

    2015-10-01

    Decomposition of soil organic matter could be an important positive feedback to climate change. Geochemical properties of soils can help determine what fraction of soil carbon may be protected from climate-induced decomposition.

  18. Probing soil respiration process of grasslands

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Soil respiration, which is primarily the only output approach for CO2 exchanges in soils between the global terrestrial ecosystem and the atmosphere,exerts a direct influence on the speed of carbon turnover rate of the soil.

  19. Relating soil biochemistry to sustainable crop production

    Science.gov (United States)

    Amino acids, amino sugars, carbohydrates, phenols, and fatty acids together comprise appreciable proportions of soil organic matter (SOM). Their cycling contribute to soil processes, including nitrogen availability, carbon sequestration and aggregation. For example, soil accumulation of phenols has ...

  20. A method to detect soil carbon degradation during soil erosion

    Directory of Open Access Journals (Sweden)

    F. Conen

    2009-11-01

    Full Text Available Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs approach (quantification of erosion rates with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri. Transects from upland (erosion source to wetland soils (erosion sinks of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 4.6 tha−1 yr−1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 500–600 and 350–400 years of erosion input into the wetlands Laui and Spissen, respectively. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

  1. A method to detect soil carbon degradation during soil erosion

    Directory of Open Access Journals (Sweden)

    C. Alewell

    2009-06-01

    Full Text Available Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs approach (quantification of erosion rates with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri. Transects from upland (erosion source to wetland soils (erosion sinks of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 2.6 t ha−1 yr−1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 800 and 400 years of erosion input into the wetlands. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

  2. Managing soil remediation problems.

    Science.gov (United States)

    Okx, J P; Hordijk, L; Stein, A

    1996-12-01

    Soil remediation has only a short history but the problem addressed is a significant one. Cost estimates for the clean-up of contaminated sites in the European Union and the United States are in the order of magnitude of 1,400 billion ECU. Such an enormous operation deserves the best management it can get. Reliable cost estimations per contaminated site are an important prerequisite. This paper addresses the problems related to site-wise estimations.When solving soil remediation problems, we have to deal with a large number of scientific disciplines. Too often solutions are presented from the viewpoint of only one discipline. In order to benefit from the combined disciplinary knowledge and experience, we think that it is necessary to describe the interrelations between these disciplines. This can be realized by developing an adequate model of the desired process which enables to consider and evaluate the essential factors as interdependent components of the total system.The resulting model provides a binding paradigm to the contributing disciplines which will result in improved efficiency and effectivity of the decision and the cost estimation process. In the near future, we will release the "Biosparging and Bioventing Expert Support System", an expert support system for problem owners, consultants and authorities dealing with the design and operation of a biosparging and/or a bioventing system.

  3. Soil Respiration: Concept and Measurement Methods

    Directory of Open Access Journals (Sweden)

    SANDOR M.

    2010-08-01

    Full Text Available Soil respiration is the main element in the carbon cycle that makes possible for plants carbon plants to return inthe atmosphere. The objective of this work was to present and discuss some aspects of the soil CO2 efflux. We definedherein, some terms associated to the soil respiration concept, we tackled some aspects regarding the influence oftemperature, humidity and soil pH on soil respiration and we presented the principle of soil respiration measurement byusing dynamic closed chamber system.

  4. Approved Practices in Soil Conservation.

    Science.gov (United States)

    Foster, Albert B.

    This book is written for individuals who wish to apply conservation practices, especially those of soil and water conservation, without technical assistance, to meet one's own conditions, and within his own capability to apply them. To meet these needs, the book includes a discussion and description of soil and water conservation methods for the…

  5. The Science of Soil Textures

    Science.gov (United States)

    Bigham, Gary

    2010-01-01

    Off-road motorcycle racing and ATV riding. Gardening and fishing. What do these high-adrenaline and slower-paced pastimes have in common? Each requires soil, and the texture of that soil has an effect on all of them. In the inquiry-based lessons described here, students work both in the field or laboratory and in the classroom to collect soil…

  6. Soil Microbiology, Ecology, and Biochemistry

    Science.gov (United States)

    The 4th edition of Soil Microbiology, Ecology, and Biochemistry Edited by Eldor Paul continues in the vein of the 3rd edition by providing an excellent, broad-reaching introduction to soil biology. The new edition improves on the previous by providing extensive supplementary materials, links to outs...

  7. BACTERIAL TRANSPORT THROUGH HOMOGENEOUS SOIL

    Science.gov (United States)

    The transport of microorganisms in soils is of major importance for bioremediation of subsurface polluted zones and for pollution of groundwater with pathogens. A procedure for evaluating the relative mobility and recovery of bacteria in the soil matrix was developed. In the meth...

  8. Monitoring and evaluating soil quality

    NARCIS (Netherlands)

    Bloem, J.; Schouten, A.J.; Sørensen, S.J.; Rutgers, M.; Werf, van der A.K.; Breure, A.M.

    2006-01-01

    This book provides a selection of microbiological methods that are already applied in regional or national soil quality monitoring programs. It is split into two parts: part one gives an overview of approaches to monitoring, evaluating and managing soil quality. Part two provides a selection of meth

  9. Soil biodiversity for agricultural sustainability

    NARCIS (Netherlands)

    Brussaard, L.; Ruiter, de P.C.; Brown, G.G.

    2007-01-01

    We critically highlight some evidence for the importance of soil biodiversity to sustaining (agro-)ecosystem functioning and explore directions for future research. We first deal with resistance and resilience against abiotic disturbance and stress. There is evidence that soil biodiversity does conf

  10. Soil strength and forest operations.

    NARCIS (Netherlands)

    Beekman, F.

    1987-01-01

    The use of heavy machinery and transport vehicles is an integral part of modern forest operations. This use often causes damage to the standing trees and to the soil. In this study the effects of vehicle traffic on the soil are analysed and the possible consequences for forest management discussed.

  11. CHEMICAL EQUILIBRIUM OF SOIL SOLUTION IN STEPPE ZONE SOIL

    Directory of Open Access Journals (Sweden)

    A. A. Batukaev

    2014-01-01

    Full Text Available Dynamics of material composition, migration and accumulation of salts is determined by chemical equilibrium in soil solution. Soil solution contains associated electrically neutral ion pairs CaCO30; CaSO40, MgCO30, MgSO40, charged ion pairs CaHCO3+, MgHCO3+, NaCO3-, NaSO4-, CaOH+, MgOH+. Calculation method is proposed for quantitative assessment of real ion forms in the soil solution of chestnut solonetz soil complex. Were proposed equations to calculate free and associated forms of ions. To solve the equations were used an iteration, a linear interpolation of equilibrium constants, a Method of Ionic Pairs including a law of initial concentration preservation, a law of the operating masses of equilibrium system, the concentration constants of ion pair dissociation on the law of operating masses. Was determined the quantity of ion free form and a coefficient of ion association as ratio of ions free form to analytical content ?e = Cass/Can. The association of ions varies in individual soils and soil layer. Increasing soil solution salinity amplifies the ions association. In form of ionic pairs in soil solution are: 11.8-53.8% of Ca2+; 9.4-57.3% of Mg2+; 0.7-11.9% of Na+; 2.2-22.3% of HCO3-, 11.8-62.7% of SO42-. The ion CO32- is high associated, the share of ions in associated form is up to 92.7%. The degree of soil solution saturation was obtained for three level of approximation accounting on analytical concentration, calculated association coefficient, calculated coefficient of association. Relating to thermodynamic solubility product S0, the mathematical product of analytical ionic pairs

  12. The impact of soil degradation on soil functioning in Europe

    Science.gov (United States)

    Montanarella, Luca

    2010-05-01

    The European Commission has presented in September 2006 its Thematic Strategy for Soil Protection.The Thematic Strategy for Soil Protection consists of a Communication from the Commission to the other European Institutions, a proposal for a framework Directive (a European law), and an Impact Assessment. The Communication (COM(2006) 231) sets the frame. It defines the relevant soil functions for Europe and identifies the major threats. It explains why further action is needed to ensure a high level of soil protection, sets the overall objective of the Strategy and explains what kind of measures must be taken. It establishes a ten-year work program for the European Commission. The proposal for a framework Directive (COM(2006) 232) sets out common principles for protecting soils across the EU. Within this common framework, the EU Member States will be in a position to decide how best to protect soil and how use it in a sustainable way on their own territory. The Impact Assessment (SEC (2006) 1165 and SEC(2006) 620) contains an analysis of the economic, social and environmental impacts of the different options that were considered in the preparatory phase of the strategy and of the measures finally retained by the Commission. Since 2006 a large amount of new evidence has allowed to further document the extensive negative impacts of soil degradation on soil functioning in Europe. Extensive soil erosion, combined with a constant loss of soil organic carbon, have raised attention to the important role soils are playing within the climate change related processes. Other important processes are related to the loss of soil biodiversity, extensive soil sealing by housing and infrastructure, local and diffuse contamination by agricultural and industrial sources, compaction due to unsustainable agricultural practices and salinization by unsustainable irrigation practices. The extended impact assessment by the European Commission has attempted to quantify in monetary terms the

  13. Mapping specific soil functions based on digital soil property maps

    Science.gov (United States)

    Pásztor, László; Fodor, Nándor; Farkas-Iványi, Kinga; Szabó, József; Bakacsi, Zsófia; Koós, Sándor

    2016-04-01

    Quantification of soil functions and services is a great challenge in itself even if the spatial relevance is supposed to be identified and regionalized. Proxies and indicators are widely used in ecosystem service mapping. Soil services could also be approximated by elementary soil features. One solution is the association of soil types with services as basic principle. Soil property maps however provide quantified spatial information, which could be utilized more versatilely for the spatial inference of soil functions and services. In the frame of the activities referred as "Digital, Optimized, Soil Related Maps and Information in Hungary" (DOSoReMI.hu) numerous soil property maps have been compiled so far with proper DSM techniques partly according to GSM.net specifications, partly by slightly or more strictly changing some of its predefined parameters (depth intervals, pixel size, property etc.). The elaborated maps have been further utilized, since even DOSoReMI.hu was intended to take steps toward the regionalization of higher level soil information (secondary properties, functions, services). In the meantime the recently started AGRAGIS project requested spatial soil related information in order to estimate agri-environmental related impacts of climate change and support the associated vulnerability assessment. One of the most vulnerable services of soils in the context of climate change is their provisioning service. In our work it was approximated by productivity, which was estimated by a sequential scenario based crop modelling. It took into consideration long term (50 years) time series of both measured and predicted climatic parameters as well as accounted for the potential differences in agricultural practice and crop production. The flexible parametrization and multiple results of modelling was then applied for the spatial assessment of sensitivity, vulnerability, exposure and adaptive capacity of soils in the context of the forecasted changes in

  14. Determining soil moisture and soil properties in vegetated areas by assimilating soil temperatures

    Science.gov (United States)

    Dong, Jianzhi; Steele-Dunne, Susan C.; Ochsner, Tyson E.; van de Giesen, Nick

    2016-06-01

    This study addresses two critical barriers to the use of Passive Distributed Temperature Sensing (DTS) for large-scale, high-resolution monitoring of soil moisture. In recent research, a particle batch smoother (PBS) was developed to assimilate sequences of temperature data at two depths into Hydrus-1D to estimate soil moisture as well as soil thermal and hydraulic properties. However, this approach was limited to bare soil and assumed that the cable depths were perfectly known. In order for Passive DTS to be more broadly applicable as a soil hydrology research and remote sensing soil moisture product validation tool, it must be applicable in vegetated areas. To address this first limitation, the forward model (Hydrus-1D) was improved through the inclusion of a canopy energy balance scheme. Synthetic tests were used to demonstrate that without the canopy energy balance scheme, the PBS estimated soil moisture could be even worse than the open loop case (no assimilation). When the improved Hydrus-1D model was used as the forward model in the PBS, vegetation impacts on the soil heat and water transfer were well accounted for. This led to accurate and robust estimates of soil moisture and soil properties. The second limitation is that, cable depths can be highly uncertain in DTS installations. As Passive DTS uses the downward propagation of heat to extract moisture-related variations in thermal properties, accurate estimates of cable depths are essential. Here synthetic tests were used to demonstrate that observation depths can be jointly estimated with other model states and parameters. The state and parameter results were only slightly poorer than those obtained when the cable depths were perfectly known. Finally, in situ temperature data from four soil profiles with different, but known, soil textures were used to test the proposed approach. Results show good agreement between the observed and estimated soil moisture, hydraulic properties, thermal properties, and

  15. MICROWAVE REMOTE SENSING IN SOIL QUALITY ASSESSMENT

    Directory of Open Access Journals (Sweden)

    S. K. Saha

    2012-08-01

    Full Text Available Information of spatial and temporal variations of soil quality (soil properties is required for various purposes of sustainable agriculture development and management. Traditionally, soil quality characterization is done by in situ point soil sampling and subsequent laboratory analysis. Such methodology has limitation for assessing the spatial variability of soil quality. Various researchers in recent past showed the potential utility of hyperspectral remote sensing technique for spatial estimation of soil properties. However, limited research studies have been carried out showing the potential of microwave remote sensing data for spatial estimation of various soil properties except soil moisture. This paper reviews the status of microwave remote sensing techniques (active and passive for spatial assessment of soil quality parameters such as soil salinity, soil erosion, soil physical properties (soil texture & hydraulic properties; drainage condition; and soil surface roughness. Past and recent research studies showed that both active and passive microwave remote sensing techniques have great potentials for assessment of these soil qualities (soil properties. However, more research studies on use of multi-frequency and full polarimetric microwave remote sensing data and modelling of interaction of multi-frequency and full polarimetric microwave remote sensing data with soil are very much needed for operational use of satellite microwave remote sensing data in soil quality assessment.

  16. Phytoremediation for Oily Desert Soils

    Science.gov (United States)

    Radwan, Samir

    This chapter deals with strategies for cleaning oily desert soils through rhizosphere technology. Bioremediation involves two major approaches; seeding with suitable microorganisms and fertilization with microbial growth enhancing materials. Raising suitable crops in oil-polluted desert soils fulfills both objectives. The rhizosphere of many legume and non-legume plants is richer in oil-utilizing micro-organisms than non-vegetated soils. Furthermore, these rhizospheres also harbour symbiotic and asymbiotic nitrogen-fixing bacteria, and are rich in simple organic compounds exuded by plant roots. Those exudates are excellent nutrients for oil-utilizing microorganisms. Since many rhizospheric bacteria have the combined activities of hydrocarbon-utilization and nitrogen fixation, phytoremediation provides a feasible and environmentally friendly biotechnology for cleaning oil-polluted soils, especially nitrogen-poor desert soils.

  17. Soil Erosion Threatens Food Production

    Directory of Open Access Journals (Sweden)

    Michael Burgess

    2013-08-01

    Full Text Available Since humans worldwide obtain more than 99.7% of their food (calories from the land and less than 0.3% from the oceans and aquatic ecosystems, preserving cropland and maintaining soil fertility should be of the highest importance to human welfare. Soil erosion is one of the most serious threats facing world food production. Each year about 10 million ha of cropland are lost due to soil erosion, thus reducing the cropland available for world food production. The loss of cropland is a serious problem because the World Health Organization and the Food and Agricultural Organization report that two-thirds of the world population is malnourished. Overall, soil is being lost from agricultural areas 10 to 40 times faster than the rate of soil formation imperiling humanity’s food security.

  18. The Presence of Plants Alters the Effect of Soil Moisture on Soil C Decomposition in Two Different Soil Types

    Science.gov (United States)

    Dijkstra, F. A.; Cheng, W.

    2005-12-01

    While it is well known that soil moisture directly affects microbial activity and soil C decomposition, it is unclear if the presence of plants alters these effects through rhizosphere processes. We studied soil moisture effects on soil C decomposition with and without sunflower and soybean. Plants were grown in two different soil types with soil moisture contents of 45 and 85% of field capacity in a greenhouse experiment. We continuously labeled plants with depleted 13C, which allowed us to separate plant-derived CO2-C from original soil-derived CO2-C in soil respiration measurements. We observed an overall increase in soil-derived CO2-C efflux in the presence of plants (priming effect) in both soils with on average a greater priming effect in the high soil moisture treatment (60% increase in soil-derived CO2-C compared to control) than in the low soil moisture treatment (37% increase). Greater plant biomass in the high soil moisture treatment contributed to greater priming effects, but priming effects remained significantly higher after correcting for plant biomass. Possibly, root exudation of labile C may have increased more than plant biomass and may have become more effective in stimulating microbial decomposition in the higher soil moisture treatment. Our results indicate that changing soil moisture conditions can significantly alter rhizosphere effects on soil C decomposition.

  19. Relationship Between Soil Properties and Different Fractions of Soil Hg

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Correlation and path analysis methods were used to study the relationship between soil properties and the distribution of different soil Hg fractions with nine representative soils from Chongqing, China. Results showed that clay (< 2 m) could increase water-soluble Hg (r = 0.700*). Soil organic matter (OM) could enhance the increase of elemental Hg (r = 0.674*). The higher the base saturation percentage (BSP), the more the residual Hg (r = 0.684*). Organic Hg, the sum of acid-soluble organic Hg. and alkali-soluble Hg, was positively affected by silt (2~20μm) but negatively affected by pH, with the direct path coefficients amounting to 1.0487 and 0.5121, respectively. The positive effect of OM and negative effect of BSP on organic Hg were the most significant, with the direct path coefficients being 0.7614 and -0.8527, respectively. The indirect effect of clay (< 2 μm) via BSP (path coefficient = 0.4186) was the highest, showing that the real influencing factor in the effect of clay (< 2 μm) on acid-soluble organic Hg was BSP. Since the available Hg fraction, water-soluble Hg, was positively affected by soil clay content, and the quite immobile and not bioavailable residual Hg by soil BSP, suitable reduction of clay content and increase of BSP would be of much help to reduce the Hg availability and Hg activity in Hg-contaminated soils.

  20. Evaluation of soil washing for radiologically contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Gombert, D. II

    1994-03-01

    Soil washing has been applied internationally to decontaminate soils due to the widespread increase in environmental awareness manifested in the United States by promulgation of the Comprehensive Environmental Response, Compensation and Liability Act, yet we continue to lack understanding on why the technique works in one application and not in another. A soil washing process typically integrates a variety of modules, each designed to decontaminate the matrix by destroying a particular phase or segregating a particle size fraction in which the contaminants are concentrated. The more known about how the contaminants are fixed, the more likely the process will succeed. Much can be learned from bioavailability studies on heavy metals in soils. Sequential extraction experiments designed to destroy one fixation mechanism at a time can be used to determine how contaminants are bound. This knowledge provides a technical basis for designing a processing strategy to efficiently decontaminate soil while creating a minimum of secondary wastes. In this study, a soil from the Idaho National Engineering Laboratory was physically and chemically characterized, then sequentially extracted to determine if soil washing could be effectively used to remove cesium, cobalt and chromium.

  1. How Soil Organic Matter Composition Controls Hexachlorobenzene-Soil-Interactions: Adsorption Isotherms and Quantum Chemical Modelling

    CERN Document Server

    Ahmed, Ashour; Kühn, Oliver

    2013-01-01

    Hazardous persistent organic pollutants (POPs) interact in soil with the soil organic matter (SOM) but this interaction is insufficiently understood at the molecular level. We investigated the adsorption of hexachlorobenzene (HCB) on soil samples with systematically modified SOM. These samples included the original soil, the soil modified by adding a hot water extract (HWE) fraction (soil+3 HWE and soil+6 HWE), and the pyrolyzed soil. The SOM contents increased in the order pyrolyzed soil < original soil < soil+3 HWE < soil+6 HWE. For the latter three samples this order was also valid for the HCB adsorption. The pyrolyzed soil adsorbed more HCB than the other samples at low initial concentrations, but at higher concentrations the HCB adsorption became weaker than in the samples with HWE addition. This adsorption behaviour combined with the differences in the chemical composition between the soil samples suggested that alkylated aromatic, phenol, and lignin monomer compounds contributed most to the HC...

  2. ESTIMATING SOIL PARTICLE-SIZE DISTRIBUTION FOR SICILIAN SOILS

    Directory of Open Access Journals (Sweden)

    Vincenzo Bagarello

    2009-09-01

    Full Text Available The soil particle-size distribution (PSD is commonly used for soil classification and for estimating soil behavior. An accurate mathematical representation of the PSD is required to estimate soil hydraulic properties and to compare texture measurements from different classification systems. The objective of this study was to evaluate the ability of the Haverkamp and Parlange (HP and Fredlund et al. (F PSD models to fit 243 measured PSDs from a wide range of 38 005_Bagarello(547_33 18-11-2009 11:55 Pagina 38 soil textures in Sicily and to test the effect of the number of measured particle diameters on the fitting of the theoretical PSD. For each soil textural class, the best fitting performance, established using three statistical indices (MXE, ME, RMSE, was obtained for the F model with three fitting parameters. In particular, this model performed better in the fine-textured soils than the coarse-textured ones but a good performance (i.e., RMSE < 0.03 was detected for the majority of the investigated soil textural classes, i.e. clay, silty-clay, silty-clay-loam, silt-loam, clay-loam, loamy-sand, and loam classes. Decreasing the number of measured data pairs from 14 to eight determined a worse fitting of the theoretical distribution to the measured one. It was concluded that the F model with three fitting parameters has a wide applicability for Sicilian soils and that the comparison of different PSD investigations can be affected by the number of measured data pairs.

  3. Uncertainty in soil carbon accounting due to unrecognized soil erosion.

    Science.gov (United States)

    Sanderman, Jonathan; Chappell, Adrian

    2013-01-01

    The movement of soil organic carbon (SOC) during erosion and deposition events represents a major perturbation to the terrestrial carbon cycle. Despite the recognized impact soil redistribution can have on the carbon cycle, few major carbon accounting models currently allow for soil mass flux. Here, we modified a commonly used SOC model to include a soil redistribution term and then applied it to scenarios which explore the implications of unrecognized erosion and deposition for SOC accounting. We show that models that assume a static landscape may be calibrated incorrectly as erosion of SOC is hidden within the decay constants. This implicit inclusion of erosion then limits the predictive capacity of these models when applied to sites with different soil redistribution histories. Decay constants were found to be 15-50% slower when an erosion rate of 15 t soil ha(-1)  yr(-1) was explicitly included in the SOC model calibration. Static models cannot account for SOC change resulting from agricultural management practices focused on reducing erosion rates. Without accounting for soil redistribution, a soil sampling scheme which uses a fixed depth to support model development can create large errors in actual and relative changes in SOC stocks. When modest levels of erosion were ignored, the combined uncertainty in carbon sequestration rates was 0.3-1.0 t CO2  ha(-1)  yr(-1) . This range is similar to expected sequestration rates for many management options aimed at increasing SOC levels. It is evident from these analyses that explicit recognition of soil redistribution is critical to the success of a carbon monitoring or trading scheme which seeks to credit agricultural activities.

  4. Predicting Soil-Air and Soil-Water Transport Properties During Soil Vapor Extraction

    DEFF Research Database (Denmark)

    Poulsen, Tjalfe

    designing and operating remediation systems. Simple and accurate models for estimating soil properties from soil parameters that are easy to measure are useful in connection with preliminary remedial investigations and evaluation of remedial technologies. In this work simple models for predicting transport...

  5. Developments and departures in the philosophy of soil science

    Science.gov (United States)

    Traditional soil science curriculums provide comprehensive instruction on soil properties, soil classification, and the physical, chemical, and biological processes that occur in soils. This reductionist perspective is sometimes balanced with a more holistic perspective that focuses on soils as natu...

  6. Soil on Phoenix Deck

    Science.gov (United States)

    2008-01-01

    This image, taken by the Surface Stereo Imager (SSI) of NASA's Phoenix Lander, shows Martian soil piled on top of the spacecraft's deck and some of its instruments. Visible in the upper-left portion of the image are several wet chemistry cells of the lander's Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The instrument on the lower right of the image is the Thermal and Evolved-Gas Analyzer. The excess sample delivered to the MECA's sample stage can be seen on the deck in the lower left portion of the image. This image was taken on Martian day, or sol, 142, on Saturday, Oct. 19, 2008. Phoenix landed on Mars' northern plains on May 25, 2008. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  7. The Spatial Variability of Soil Dehydrogenase Activity: A Survey in Urban Soils

    OpenAIRE

    Ridvan Kizilkaya; Tayfun Aşkin

    2007-01-01

    Information on soil microorganisms and their activity used to determine microbiological characteristics are very important for soil quality and productivity. Studies of enzyme activities provide information on the biochemical processes occurring in soil. There is growing evidence that soil biological parameters may be potential and sensitive indicators of soil ecological conditions and soil management. Soil microbiological parameters may be evaluated statistically due to application of geosta...

  8. Tracing soil erosion impacts on soil organisms using 137Cs and soil nematodes

    Science.gov (United States)

    Baxter, Craig; Rowan, John S.; McKenzie, Blair M.; Neilson, Roy

    2014-05-01

    The application of environmental radionuclides in soil tracing and erosion studies is now well established in geomorphology. Sediment and erosion-tracing studies are undertaken for a range of purposes in the earth sciences but until now few studies have used the technique to answer biological questions. An experiment was undertaken to measure patterns of soil loss and gain over 50 years, effectively calculating a field-scale sediment budget, to investigate soil erosion relationships between physical and biological soil components. Soil nematodes were identified as a model organism, a ubiquitous and abundant group sensitive to disturbance and thus useful indicator taxa of biological and physico-chemical changes. A field site was selected at the James Hutton Institute's experimental Balruddery Farm in NE Scotland. 10 metre-resolution topographical data was collected with differential GPS. Based on these data, a regular 30 m-resolution sampling grid was constructed in ArcGIS, and a field-sampling campaign undertaken. 104 soil cores (~50 cm-deep) were collected with a percussion corer. Radio-caesium (137Cs) activity concentrations were measured using high-purity germainum gamma-ray spectroscopy, and 137Cs areal activities derived from these values. Organic matter content by loss on ignition and grain-size distribution by laser granulometry were also measured. Additional samples were collected to characterise the soil nematode community, both for abundance and functional (trophic) composition using a combination of low-powered microscopy and molecular identification techniques (dTRFLP). Results were analysed with ArcGIS software using the Spatial Analyst package. Results show that spatial relationships between physical, chemical and biological parameters were complex and interrelated. Previous field management was found to influence these relationships. The results of this experiment highlight the role that soil erosion processes play in medium-term restructuring of the

  9. Soil warming affects soil organic matter chemistry of all density fractions of a mountain forest soil

    Science.gov (United States)

    Schnecker, Jörg; Wanek, Wolfgang; Borken, Werner; Schindlbacher, Andreas

    2016-04-01

    Rising temperatures enhance microbial decomposition of soil organic matter (SOM) and increase thereby the soil CO2 efflux. Elevated microbial activity might differently affect distinct SOM pools, depending on their stability and accessibility. Soil fractions derived from density fractionation have been suggested to represent SOM pools with different turnover times and stability against microbial decomposition. We here investigated the chemical and isotopic composition of bulk soil and three different density fractions of forest soils from a long term warming experiment in the Austrian Alps. At the time of sampling the soils in this experiment had been warmed during the snow-free period for 8 consecutive years. During that time no thermal adaptation of the microbial community could be identified and CO2 release from the soil continued to be elevated by the warming treatment. Our results which included organic C content, total N content, δ13C, δ 14C, δ 15N and the chemical composition, identified by pyrolysis-GC/MS, showed no significant differences in bulk soil between warming treatment and control. The differences in the three individual fractions (free particulate organic matter, occluded particulate organic matter and mineral associated organic matter) were mostly small and the direction of warming induced change was variable with fraction and sampling depth. We did however find statistically significant effects of warming in all density fractions from 0-10 cm depth, 10-20 cm depth or both. Our results also including significant changes in the supposedly more stable mineral associated organic matter fraction where δ 13C values decreased at both sampling depths and the relative proportion of N-bearing compounds decreased at a sampling depth of 10-20 cm. All the observed changes can be attributed to an interplay of enhanced microbial decomposition of SOM and increased root litter input. This study suggests that soil warming destabilizes all density fractions of

  10. A Review of Fishpond Soil Management Principles in Nigeria

    OpenAIRE

    A.T. Ekubo; J.F.N. Abowei

    2011-01-01

    The suitability of sites for culture fisheries depends on the soil. There is therefore the need to have proper background on the nature and properties of soils. The pond oils, soil functions in fish pond, soil characterization, components and soil mineral constituents, oil profile soil classification, soil fertility, nutrients, primary and secondary nutrients, soil organic matter, common soil problems, field and laboratory methods in acid sulphate soil identification, management of acid sulph...

  11. Long-term effects of soil management on ecosystem services and soil loss estimation in olive grove top soils

    NARCIS (Netherlands)

    Parras-Alcántara, Luis; Lozano-García, Beatriz; Keesstra, Saskia; Cerdà, Artemi; Brevik, Eric C.

    2016-01-01

    Soil management has important effects on soil properties, runoff, soil losses and soil quality. Traditional olive grove (OG) management is based on reduced tree density, canopy size shaped by pruning and weed control by ploughing. In addition, over the last several decades, herbicide use has been

  12. Decomposition of Diethylstilboestrol in Soil

    DEFF Research Database (Denmark)

    Gregers-Hansen, Birte

    1964-01-01

    The rate of decomposition of DES-monoethyl-1-C14 in soil was followed by measurement of C14O2 released. From 1.6 to 16% of the added C14 was recovered as C14O2 during 3 months. After six months as much as 12 to 28 per cent was released as C14O2.Determination of C14 in the soil samples after the e...... not inhibit the CO2 production from the soil.Experiments with γ-sterilized soil indicated that enzymes present in the soil are able to attack DES.......The rate of decomposition of DES-monoethyl-1-C14 in soil was followed by measurement of C14O2 released. From 1.6 to 16% of the added C14 was recovered as C14O2 during 3 months. After six months as much as 12 to 28 per cent was released as C14O2.Determination of C14 in the soil samples after...

  13. The soil reference shrinkage curve

    CERN Document Server

    Chertkov, V Y

    2014-01-01

    A recently proposed model showed how a clay shrinkage curve is transformed to the soil shrinkage curve at the soil clay content higher than a critical one. The objective of the present work was to generalize this model to the soil clay content lower a critical one. I investigated (i) the reference shrinkage curve, that is, one without cracks; (ii) the superficial layer of aggregates, with changed pore structure compared with the intraaggregate matrix; and (iii) soils with sufficiently low clay content where there are large pores inside the intraaggregate clay (so-called lacunar pores). The methodology is based on detail accounting for different contributions to the soil volume and water content during shrinkage. The key point is the calculation of the lacunar pore volume variance at shrinkage. The reference shrinkage curve is determined by eight physical soil parameters: (1) oven-dried specific volume; (2) maximum swelling water content; (3) mean solid density; (4) soil clay content; (5) oven-dried structural...

  14. Soil Organic Carbon dynamics in agricultural soils of Veneto Region

    Science.gov (United States)

    Bampa, F. B.; Morari, F. M.; Hiederer, R. H.; Toth, G. T.; Giandon, P. G.; Vinci, I. V.; Montanarella, L. M.; Nocita, M.

    2012-04-01

    One of the eight soil threats expressed in the European Commission's Thematic Strategy for Soil Protection (COM (2006)231 final) it's the decline in Soil Organic Matter (SOM). His preservation is recognized as with the objective to ensure that the soils of Europe remain healthy and capable of supporting human activities and ecosystems. One of the key goals of the strategy is to maintain and improve Soil Organic Carbon (SOC) levels. As climate change is identified as a common element in many of the soil threats, the European Commission (EC) intends to assess the actual contribution of the soil protection to climate change mitigation and the effects of climate change on the possible depletion of SOM. A substantial proportion of European land is occupied by agriculture, and consequently plays a crucial role in maintaining natural resources. Organic carbon preservation and sequestration in the EU's agricultural soils could have some potential to mitigate the effects of climate change, particularly linked to preventing certain land use changes and maintaining SOC stocks. The objective of this study is to assess the SOC dynamics in agricultural soils (cropland and grassland) at regional scale, focusing on changes due to land use. A sub-objective would be the evaluation of the most used land management practices and their effect on SOC content. This assessment aims to determine the geographical distribution of the potential GHG mitigation options, focusing on hot spots in the EU, where mitigation actions would be particularly efficient and is linked with the on-going work in the JRC SOIL Action. The pilot area is Veneto Region. The data available are coming from different sources, timing and involve different variables as: soil texture, climate, soil disturbance, managements and nutrients. The first source of data is the LUCAS project (Land Use/Land Cover Area Frame statistical Survey). Started in 2001, the LUCAS project aims to monitor changes in land cover/use and

  15. Remediation of contaminated soil using soil washing-a review

    Directory of Open Access Journals (Sweden)

    N.Karthika

    2016-01-01

    Full Text Available Pb, Zn, Ni, Cu, Mn and Cd are heavy metals occur naturally as trace elements in many soils. The present paper reviews the remediation of heavy metals of contaminated soil by soil washing using different agents. It was noted that the contact time, pH, concentration of extract ant and agitation speed were affected the process while remediation, so accordingly select the conditions to obtain efficiency which is mainly depend upon the type of soil, contaminationtype, contamination period and metals present in it.EDTA is effective when compared with other chelating agents for heavy metals especially for lead but it has low biodegradation. Because of the nature of low biodegradability, EDTA can be reusedfurther by membrane separation and electrochemical treatment, or degraded by advanced oxidation processes.

  16. Passive microwave soil moisture research

    Science.gov (United States)

    Schmugge, T.; Oneill, P. E.; Wang, J. R.

    1986-01-01

    During the four years of the AgRISTARS Program, significant progress was made in quantifying the capabilities of microwave sensors for the remote sensing of soil moisture. In this paper, a discussion is provided of the results of numerous field and aircraft experiments, analysis of spacecraft data, and modeling activities which examined the various noise factors such as roughness and vegetation that affect the interpretability of microwave emission measurements. While determining that a 21-cm wavelength radiometer was the best single sensor for soil moisture research, these studies demonstrated that a multisensor approach will provide more accurate soil moisture information for a wider range of naturally occurring conditions.

  17. Dynamic Soil-Structure-Interaction

    DEFF Research Database (Denmark)

    Kellezi, Lindita

    1998-01-01

    The aim of this thesis is to investigate and develop alternative methods of analyzing problems in dynamic soil-structure-interaction. The main focus is the major difficulty posed by such an analysis - the phenomenon of waves which radiate outward from the excited structures towards infinity...... transmitting boundary at the edges of the computational mesh. To start with, an investigation of the main effects of the interaction phenomena is carried out employing a widely used model, considering dynamic stiffness of the unbounded soil as frequency independent. Then a complete description...... represents an attempt to construct a local stiffness for the unbounded soil domain....

  18. Biochar degradation in different soils

    Science.gov (United States)

    Wilske, B.; Bai, M.; Eckhardt, C.; Kammann, C.; Kraft, P.; Bach, M.; Frede, H.-G.; Breuer, L.

    2012-04-01

    Current expectations in biochar products (BC) are numerous, e.g., including improved soil fertility & plant growth, support to combat desertification, and an increase in the carbon sequestration of soils. Costs for biochar production & application must be covered by a positive budget of benefits, which may crucially depend on the residence time (or half life T1/2, yr) of BC in soils. The objective of the present study was to assess the biodegradation rates of BC in different soils by means of a cost-efficient and standardized laboratory method. Investigated BC were from the source material of the C4 plant Miscanthus, and converted via (1) pyrolysis (pyrBC) and (2) hydrothermal carbonization (htcBC). The high-labelling of the educt allowed the quantification of degradation by measurement of the 13CO2 efflux. The pyrBC and htcBC were mixed with four different agricultural soils ranging in texture from sand to loam and in soil organic carbon (SOC) from 0.63% to 2.53%. Four samples of each BC-soil combination (1% BC wt/wt in a 300-g sample mixture) and soil-only reference were incubated in 1-L glass bottles at 40% water holding capacity and 25° C. Biodegradation of BC was monitored weekly over a period of 7 months using an automated open-dynamic chamber system. The system couples the batch of samples to microprocessor- controlled valves, by which flushing is provided for the batch, while individual samples are consecutively connected through to a wavelength scan cavity ring down spectrometer (WS-CRDS). Net 13CO2 efflux from BC was obtained by subtracting the 13CO2 efflux from "soil-only" samples. T1/2 was calculated based on the ln(k)-based algorithm recently suggested by Zimmerman et al. (2010). Results show an orders-of-magnitude larger T1/2 of BC in poor sandy soil than in SOC-richer soils (T1/2 up to 106 yrs) but not a statistically clear trend of biodegradability along the four-point SOC gradient. This was similar in both BC types, although T1/2 was generally

  19. Soil Albedo in Relation to Soil Color, Moisture and Roughness

    Science.gov (United States)

    Fontes, Adan Fimbres

    Land surface albedo is the ratio of reflected to incident solar radiation. It is a function of several surface parameters including soil color, moisture, roughness and vegetation cover. A better understanding of albedo and how it changes in relation to variations in these parameters is important in order to help improve our ability to model the effects of land surface modifications on climate. The objectives of this study were (1) To determine empirical relationships between smooth bare soil albedo and soil color, (2) To develop statistical relationships between albedo and ground-based thematic mapper (TM) measurements of spectral reflectances, (3) To determine how increased surface roughness caused by tillage reduces bare soil albedo and (4) To empirically relate albedo with TM data and other physical characteristics of mixed grass/shrubland sites at Walnut Gulch Watershed. Albedos, colors and spectral reflectances were measured by Eppley pyranometer, Chroma Meter CR-200 and a Spectron SE-590, respectively. Measurements were made on two field soils (Gila and Pima) at the Campus Agricultural Center (CAC), Tucson, AZ. Soil surface roughness was measured by a profile meter developed by the USDA/ARS. Additional measurements were made at the Maricopa Agricultural Center (MAC) for statistical model testing. Albedos of the 15 smooth, bare soils (plus silica sand) were determined by linear regression to be highly correlated (r^2 = 0.93, p > 0.01) with color values for both wet and dry soil conditions. Albedos of the same smooth bare soils were also highly correlated (r^2>=q 0.86, p > 0.01) with spectral reflectances. Testing of the linear regression equations relating albedo to soil color and spectral reflectances using the data from MAC showed a high correlation. A general nonlinear relationship given by y = 8.366ln(x) + 37.802 r^2 = 0.71 was determined between percent reduction in albedo (y) and surface roughness index (x) for wet and dry Pima and Gila field soils

  20. Rapid Soil Stabilization of Soft Clay Soils for Contingency Airfields

    Science.gov (United States)

    2006-12-01

    LiquiBlock 40K and 41K are both potassium salts of crosslinked polyacrylic acids/ polyacrylamide copolymers in granular form that also gel in the presence...with the soil water and cure. Unlike strength loss due to the fibers bunching, adding the cement on the second day only results in a reduction of the...the method of treatment, which Maclean (1956) has found to have significantly different correlated CBR and UCS values, where soils with higher friction

  1. Soils of Walker Branch Watershed

    Energy Technology Data Exchange (ETDEWEB)

    Lietzke, D.A.

    1994-01-01

    The soil survey of Walker Branch Watershed (WBW) utilized the most up-to-date knowledge of soils, geology, and geohydrology in building the soils data base needed to reinterpret past research and to begin new research in the watershed. The soils of WBW were also compared with soils mapped elsewhere along Chestnut Ridge on the Oak Ridge Reservation to (1) establish whether knowledge obtained elsewhere could be used within the watershed, (2) determine whether there were any soils restricted to the watershed, and (3) evaluate geologic formation lateral variability. Soils, surficial geology, and geomorphology were mapped at a scale of 1:1200 using a paper base map having 2-ft contour intervals. Most of the contours seemed to reasonably represent actual landform configurations, except for dense wooded areas. For example, the very large dolines or sinkholes were shown on the contour base map, but numerous smaller ones were not. In addition, small drainageways and gullies were often not shown. These often small but important features were located approximately as soil mapping progressed. WBW is underlain by dolostones of the Knox Group, but only a very small part of the surface area contains outcroppings of rock and most outcrops were located in the lower part. Soil mapping revealed the presence of both ancient alluvium and ancient colluvium deposits, not recognized in previous soil surveys, that have been preserved in high-elevation stable portions of present-day landforms. An erosional geomorphic process of topographic inversion requiring several millions of years within the Pleistocene is necessary to bring about the degree of inversion that is expressed in the watershed. Indeed, some of these ancient alluvial and colluvial remnants may date back into the Tertiary. Also evident in the watershed, and preserved in the broad, nearly level bottoms of dolines, are multiple deposits of silty material either devoid or nearly devoid of coarse fragments. Recent research

  2. Occurrence of entomopathogenic fungi in arable soil

    Directory of Open Access Journals (Sweden)

    Ryszard Miętkiewski

    2014-08-01

    Full Text Available Samples of soil were taken from arable field and from balk. Larvae of Galleria mellonella and Ephestia kühniella were used as an "insect bait" for isolation of entomopathogenic fungi from soil. Metarhizium anisopliae and Paecilomyces fumosoroseus were isolated from both kind of soil. but Beauveria bassiana was present only in soil taken from balk.

  3. Careers in Science: Being a Soil Scientist

    Science.gov (United States)

    Bryce, Alisa

    2015-01-01

    Being a soil scientist is a fascinating and certainly diverse career, which can indeed involve working in a laboratory or diagnosing sick orange trees. However it often involves much, much more. In 2015, as part of the United Nations' "International Year of Soils," Soil Science Australia's (SSA) "Soils in Schools" program…

  4. Degradation of Soil Nutrients in Southeast China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A total of 2190 soil nutrient data in the Second National Soil Survey of China were collected to assess the degradation of soil nutrients in the hilly region of Southeast China. The definition of soil nutrient degradation is suggested firstly, then the evaluation criteria are set up and the current status of degradation of red soil and latosol is assessed. The percentages of areas in four grades of soil nutrient degradation, i.e., slightly deficient, medium deficient, severely deficient and extremely deficient, were 21.3%, 43.3%, 16.2% and 3.0% for soil total N; 0.7%, 6.4%, 16.7% and 76.2% for soil available P; and 25.4%, 26.3%, 8.6% and 5.0% for soil available K, respectively. The severity of soil nutrient degradation was in the order of P > N > K. The major factors leading to the degradation of soil nutrients in quantity include soil erosion, leaching and the consumption by crops. And the principal factor affecting the degradation of soil nutrients in availability is the fixation of N, P and K, especially the fixation of phosphorus. The average amount of P fixed by soils is 408 mg kg-1, and upland soils can fix more P than paddy soils.

  5. Progress of Soil Research in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Soil,as a survival natural resource for the existent of human beings,is always highly concerned by contemporary scientists.Being a tag to symbolize the development level of soil science,research in soil classification is a focus in today's international soil science.

  6. Vital Soil: Function, Value and Properties.

    Science.gov (United States)

    This article is a review of the book, Vital Soil: Function, Value and Properties. Soil vitality has been defined as the ability of soil ecosystems to stay in balance in a changing world. The soil environment and the life that it supports developed over centuries and millennia, but careless human ac...

  7. On the assessment of root and soil respiration for soils of different textures: interactions with soil moisture contents and soil CO2 concentrations

    NARCIS (Netherlands)

    Bouma, T.J.; Bryla, D.R.

    2000-01-01

    Estimates of root and soil respiration are becoming increasingly important in agricultural and ecological research, but there is little understanding how soil texture and water content may affect these estimates. We examined the effects of soil texture on (i) estimated rates of root and soil respira

  8. Nematode survival in relation to soil moisture

    NARCIS (Netherlands)

    Simons, W.R.

    1973-01-01

    Established nematode populations are very persistent in the soil. It is known that they need sufficient soil moisture for movement, feeding and reproduction (fig. 5), and that there are adverse soil moisture conditions which they cannot survive. The influence of soil moisture on survival of nematode

  9. Soil Erosion. LC Science Tracer Bullet.

    Science.gov (United States)

    Buydos, John F., Comp.

    Soil erosion is the detachment and movement of topsoil or soil material from the upper part of the soil profile. It may occur in the form of rill, gully, sheet, or wind erosion. Agents of erosion may be water, wind, glacial ice, agricultural implements, machinery, and animals. Soil conservation measures require a thorough understanding of the…

  10. Humble View on Soil Water Resources

    Institute of Scientific and Technical Information of China (English)

    CHENZHI-XIONG; ZHOULIU-ZONG

    1993-01-01

    Soil water is one of renewable water resources.Some properties of soil water concerning with its availability to plant are briefly described.An equation for estimating the amount of soil water resource is presented.Based on the evaporation demand of atmosphere,the evaluation coefficient for soil water resource is suggested.

  11. 30 CFR 715.14 - Backfilling and grading.

    Science.gov (United States)

    2010-07-01

    ... configuration and the outslopes of the plateau shall not exceed 1v:2h, except where engineering data... used to meet the requirements of paragraph (j) of this section. (f) Definition of thin and thick... protect against upward migration of salts, exposure by erosion, to provide an adequate depth for...

  12. GS Soil - Assessment and strategic development of INSPIRE compliant Geodata-Services for European Soil Data

    DEFF Research Database (Denmark)

    Krogh, Paul Henning; Münier, Bernd

    facilities and long term observations as part of the Annex III theme "Environmental Monitoring Facilities", • Information about the soil related aspects of Annex III theme "Natural Risk Zones" as e.g. landslides, soil erosion, soil compaction, soil organic carbon decline, salinization, acidification and soil...

  13. EuroSoil2012: Soil science for the benefit of mankind and environment

    Science.gov (United States)

    EuroSoil2012 was convened in Bari ITALY from 2-6 July 2012 as the 4th International Congress of the European Confederation of Soil Science Societies (ECSSS). The theme of EuroSoil2012 as “soil science for the benefit of mankind and environment” aimed to cover several broad aspects of soil science w...

  14. Effects of environmental factors and soil properties on topographic variations of soil respiration

    Directory of Open Access Journals (Sweden)

    K. Tamai

    2010-03-01

    Full Text Available Soil respiration rates were measured along different parts of a slope in (a an evergreen forest with common brown forest soil and (b a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soil moisture and soil temperature. These results may be explained by the fact that different soil properties matured within different environments. It can be argued that the low soil respiration rates in the low parts of the slope in the evergreen forest resulted from soil properties and not from wet soil conditions. In the deciduous forest, soil respiration rates were more strongly affected by soil moisture and soil temperature than by soil properties. These effects were likely due to the immaturity of the forest soil.

  15. Refining soil survey information for a Dutch soil series using land use history

    NARCIS (Netherlands)

    Sonneveld, M.P.W.; Bouma, J.; Veldkamp, A.

    2002-01-01

    Differences in land-use history within soil series, although not influencing soil classification, lead to variability of non-diagnostic soil properties in soil databases. Regional studies that use soil databases are confronted with this considerable variability. This has, for example, been reported

  16. Students Dig Deep in the Mystery Soil Lab: A Playful, Inquiry-Based Soil Laboratory Project

    Science.gov (United States)

    Thiet, Rachel K.

    2014-01-01

    The Mystery Soil Lab, a playful, inquiry-based laboratory project, is designed to develop students' skills of inquiry, soil analysis, and synthesis of foundational concepts in soil science and soil ecology. Student groups are given the charge to explore and identify a "Mystery Soil" collected from a unique landscape within a 10-mile…

  17. Worldwide organic soil carbon and nitrogen data

    Energy Technology Data Exchange (ETDEWEB)

    Zinke, P.J.; Stangenberger, A.G. [Univ. of California, Berkeley, CA (United States). Dept. of Forestry and Resource Management; Post, W.M.; Emanual, W.R.; Olson, J.S. [Oak Ridge National Lab., TN (United States)

    1986-09-01

    The objective of the research presented in this package was to identify data that could be used to estimate the size of the soil organic carbon pool under relatively undisturbed soil conditions. A subset of the data can be used to estimate amounts of soil carbon storage at equilibrium with natural soil-forming factors. The magnitude of soil properties so defined is a resulting nonequilibrium values for carbon storage. Variation in these values is due to differences in local and geographic soil-forming factors. Therefore, information is included on location, soil nitrogen content, climate, and vegetation along with carbon density and variation.

  18. Economic Analysis on Monetization of Soil Functions

    Institute of Scientific and Technical Information of China (English)

    Zenglei; XI; Shaoqing; ZHANG

    2013-01-01

    On the basis of making clear diversity characteristics of soil functions and multiple characteristics of income, this paper points out that the monetization of soil functions based functional maintenance and change decision process can be regarded as a game process of different utilization methods at the background of different functions. The balance of this game process will determine monetary value of soil functions. After understanding money and monetization concepts, it introduces that measurability and exchangeability of soil functions provide objective conditions for monetization of soil functions. Finally, it discusses that usefulness value of soil functions provide basis for monetization of soil functions.

  19. Impact of soil properties on selected pharmaceuticals adsorption in soils

    Science.gov (United States)

    Kodesova, Radka; Kocarek, Martin; Klement, Ales; Fer, Miroslav; Golovko, Oksana; Grabic, Roman; Jaksik, Ondrej

    2014-05-01

    The presence of human and veterinary pharmaceuticals in the environment has been recognized as a potential threat. Pharmaceuticals may contaminate soils and consequently surface and groundwater. Study was therefore focused on the evaluation of selected pharmaceuticals adsorption in soils, as one of the parameters, which are necessary to know when assessing contaminant transport in soils. The goals of this study were: (1) to select representative soils of the Czech Republic and to measure soil physical and chemical properties; (2) to measure adsorption isotherms of selected pharmaceuticals; (3) to evaluate impact of soil properties on pharmaceutical adsorptions and to propose pedotransfer rules for estimating adsorption coefficients from the measured soil properties. Batch sorption tests were performed for 6 selected pharmaceuticals (beta blockers Atenolol and Metoprolol, anticonvulsant Carbamazepin, and antibiotics Clarithromycin, Trimetoprim and Sulfamethoxazol) and 13 representative soils (soil samples from surface horizons of 11 different soil types and 2 substrates). The Freundlich equations were used to describe adsorption isotherms. The simple correlations between measured physical and chemical soil properties (soil particle density, soil texture, oxidable organic carbon content, CaCO3 content, pH_H2O, pH_KCl, exchangeable acidity, cation exchange capacity, hydrolytic acidity, basic cation saturation, sorption complex saturation, salinity), and the Freundlich adsorption coefficients were assessed using Pearson correlation coefficient. Then multiple-linear regressions were applied to predict the Freundlich adsorption coefficients from measured soil properties. The largest adsorption was measured for Clarithromycin (average value of 227.1) and decreased as follows: Trimetoprim (22.5), Metoprolol (9.0), Atenolol (6.6), Carbamazepin (2.7), Sulfamethoxazol (1.9). Absorption coefficients for Atenolol and Metoprolol closely correlated (R=0.85), and both were also

  20. Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land

    Science.gov (United States)

    Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.

    2016-08-01

    A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

  1. Thermo-diffusional radon waves in soils.

    Science.gov (United States)

    Minkin, Leonid; Shapovalov, Alexander S

    2016-09-15

    A new theoretical framework for diurnal and seasonal oscillations of the concentration of radon in soil and open air is proposed. The theory is based on the existing temperature waves in soils and thermo-diffusional gas flux in porous media. As soil is a non-isothermal porous medium, usually possessing a large fraction of microscopic pores belonging to Knudsen's free molecular field, a thermo-diffusional gas flow in soil has to arise. The radon mass transfer equation in soil for sinusoidal temperature oscillations at the soil-atmosphere boundary is solved, which reveals that radon concentration behaves as a damped harmonic wave. The amplitude of radon concentration oscillations and phase shift between radon concentration oscillations and soil temperature depend on the radon diffusion coefficient in soil, rate of radon production, soil thermal conductivity, average soil temperature, decay constant, and heat of radon transfer. Primarily numerical calculations are presented and comparisons with experimental data are shown.

  2. Biochar as a soil amendment

    Directory of Open Access Journals (Sweden)

    Medyńska-Juraszek Agnieszka

    2016-09-01

    Full Text Available Biochar is a carbonaceous product of biomass pyrolysis under limited oxygen conditions. Due to the very good sorption properties material is used as a soil amendment. In recent years, much attention has been paid to biochar as a potential tool improving soil properties and fertility. The most important benefits of its use in agriculture is a significant increase of sorption capacity, reduced nutrient leaching, as well as slow release of macro- and microelements essential for plant growth, liming effect, increased water holding capacity, improved biological properties, resulting in an increase in crop yields. The aim of the study is to summarize the knowledge about the impact of biochar on soil environment, as well as identify areas and directions for future research on biochar application in soils impacted by human activities

  3. Ash in the Soil System

    Science.gov (United States)

    Pereira, P.

    2012-04-01

    Ash is the organic and inorganic residue produced by combustion, under laboratory and field conditions. This definition is far away to be accepted. Some researchers consider ash only as the inorganic part, others include also the material not completely combusted as charcoal or biochar. There is a need to have a convergence about this question and define clear "what means ash". After the fire and after spread ash onto soil surface, soil properties can be substantially changed depending on ash properties, that can be different according to the burned residue (e.g wood, coal, solid waste, peppermill, animal residues), material treatment before burning, time of exposition and storage conditions. Ash produced in boilers is different from the produced in fires because of the material diferent propertie and burning conditions. In addition, the ash produced in boilers is frequently treated (e.g pelletization, granulation, self curing) previously to application, to reduce the negative effects on soil (e.g rapid increase of pH, mycorrhiza, fine roots of trees and microfauna). These treatments normally reduce the rate of nutrients dissolution. In fires this does not happen. Thus the implications on soil properties are logically different. Depending on the combustion temperature and/or severity, ash could have different physical (e.g texture, wettability) and chemical properties (e.g amount and type of total and leached nutrients) and this will have implications on soil. Ash can increase and decrease soil aggregation, wettablity and water retention, bulk density, runoff and water infiltration. Normally, ash increases soil pH, Electrical Conductivity, and the amount of some basic nutrients as calcium, magnesium, sodium and potassium. However it is also a potential source of heavy metals, especially if ash pH is low. However the effect of ash on soil in space and time depends especially of the ash amount and characteristics, fire temperature, severity, topography, aspect

  4. Soil and Rock Mechanics Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The 10,000-sq ft soil mechanics research facility is the largest in the Department of Defense and has a loading capability of 250,000 lb on triaxial specimens up to...

  5. Phytoremediation of Soil Trace Elements

    Science.gov (United States)

    Phytoremediation includes several distinct approaches to using plants to achieve soil remediation goals. Phytoextraction uses rare hyperaccumulator plants to accumulate in their shoots enough metals per year to achieve decontamination goals. Phytomining uses hyperaccumulators and biomass burn to pro...

  6. Colloid Release from Soil Aggregates

    DEFF Research Database (Denmark)

    Vendelboe, Anders Lindblad; Møldrup, Per; Schjønning, Per;

    2012-01-01

    The content of water-dispersible colloids (WDC) has a major impact on soil functions and structural stability. In addition, the presence of mobile colloids may increase the risk of colloid-facilitated transport of strongly sorbing environmental contaminants. The WDC content was measured in 39 soils......, using laser diffraction, by agitating the samples using a wet-dispersion unit. This approach eliminated the need for long sedimentation times required by the more classical end-over-end shaking approach and provided information about the time-dependent release of WDC. The total clay content of the soils...... ranged from 0.1 to 0.44 kg kg−1. The WDC content was measured on air-dry and moist 1- to 2-mm aggregates. The WDC content at a reference time was highly correlated to the total clay content (r > 0.91, P soils. Only for two sites was the WDC content correlated to the content of clay...

  7. Quantifying the heterogeneity of soil compaction, physical soil properties and soil moisture across multiple spatial scales

    Science.gov (United States)

    Coates, Victoria; Pattison, Ian; Sander, Graham

    2016-04-01

    England's rural landscape is dominated by pastoral agriculture, with 40% of land cover classified as either improved or semi-natural grassland according to the Land Cover Map 2007. Since the Second World War the intensification of agriculture has resulted in greater levels of soil compaction, associated with higher stocking densities in fields. Locally compaction has led to loss of soil storage and an increased in levels of ponding in fields. At the catchment scale soil compaction has been hypothesised to contribute to increased flood risk. Previous research (Pattison, 2011) on a 40km2 catchment (Dacre Beck, Lake District, UK) has shown that when soil characteristics are homogeneously parameterised in a hydrological model, downstream peak discharges can be 65% higher for a heavy compacted soil than for a lightly compacted soil. However, at the catchment scale there is likely to be a significant amount of variability in compaction levels within and between fields, due to multiple controlling factors. This research focusses in on one specific type of land use (permanent pasture with cattle grazing) and areas of activity within the field (feeding area, field gate, tree shelter, open field area). The aim was to determine if the soil characteristics and soil compaction levels are homogeneous in the four areas of the field. Also, to determine if these levels stayed the same over the course of the year, or if there were differences at the end of the dry (October) and wet (April) periods. Field experiments were conducted in the River Skell catchment, in Yorkshire, UK, which has an area of 120km2. The dynamic cone penetrometer was used to determine the structural properties of the soil, soil samples were collected to assess the bulk density, organic matter content and permeability in the laboratory and the Hydrosense II was used to determine the soil moisture content in the topsoil. Penetration results show that the tree shelter is the most compacted and the open field area

  8. Structure and composition of soils

    Directory of Open Access Journals (Sweden)

    Snežana Nenadović

    2010-12-01

    Full Text Available This paper presents a study of soils structure and composition using up to date technique, such as scanning electronic microscopy, atomic force microscopy, X-ray diffraction, X-ray fluorescence, as well as some other characterization methods. It was shown that soil particles have porous structure and dimensions in the range from several millimeters to several hundreds of nanometers and consist of different minerals such as kaolin, quartz and feldspate.

  9. Using nematodes in soil ecotoxicology.

    Science.gov (United States)

    Sochová, Ivana; Hofman, Jakub; Holoubek, Ivan

    2006-04-01

    Nematodes represent a very abundant group of soil organisms and non-parasitic species are important for soil quality and in the soil food web. In recent years, it has been shown that nematodes are appropriate bioindicators of soil condition and they are also suitable organisms for laboratory toxicity testing. The aims of this paper are to overview and critically assess methods and approaches for researching soil nematode ecotoxicology. In natural ecosystems, nematode abundance and community structure analyses were proved to be sensitive indicators of stress caused by soil pollutants and ecological disturbance. Community structure analyses may be approached from a functional or ecological point of view; species are divided into groups according to their feeding habits or alternatively the maturity index is calculated according to their ecological strategy. Many environmental factors have the potential to affect nematode community, which consequently results in high space and time variability. This variance is major handicap in field ecotoxicological studies because pollutant-nematode relationships are obscured. For prospective risk assessment of chemicals, several toxicity tests with nematodes were developed and are increasingly used. Sensitivity of these tests is comparable to tests with other soil species (e.g. enchytraeids, earthworms and springtails) while tests are less demanding to space and time. Most studies have focused on metal toxicity but organic compounds are almost overlooked. Endpoints used in tests were often mortality, reproduction or movement, but more sublethal endpoints such as feeding or biomarkers have been used recently too. Although there is an increasing amount of knowledge in soil nematode ecotoxicology, there is still a lot of various issues in this topic to research.

  10. Permafrost soils and carbon cycling

    OpenAIRE

    Ping, C. L.; J. D. Jastrow; Jorgenson, M. T.; G. J. Michaelson; Y. L. Shur

    2015-01-01

    Knowledge of soils in the permafrost region has advanced immensely in recent decades, despite the remoteness and inaccessibility of most of the region and the sampling limitations posed by the severe environment. These efforts significantly increased estimates of the amount of organic carbon stored in permafrost-region soils and improved understanding of how pedogenic processes unique to permafrost environments built enormous organic carbon stocks during the Quaternary. This...

  11. Geotehnical Properties of Plastic Stabilized Lateritic Soil

    OpenAIRE

    Akinola Johnson Olarewaju

    2016-01-01

    Stabilization is the combination of soils and additives to change its properties and remain in its stable compacted state without undergoing any change under effect of exposure to weather and traffic. Soil stabilization through the reinforced soil construction is an efficient and reliable technique for improving the strength and stability of soils. The lateritic soil used in this study was taken along Papa-Ilaro road Ajegunle at Abalabi, Ogun State, Nigeria and the solid plastic wastes were t...

  12. Enzyme activity in forest peat soils

    OpenAIRE

    Błońska, Ewa

    2010-01-01

    The aim of the study was to determine the activity of dehydrogenases and urease in forest peat soils of different fertility. There were selected 23 experimental plots localised in central and northern Poland. The research was conducted on forest fens, transition bogs and raised bogs. The biggest differences in soil physical and chemical properties were detected between fen and raised bog soils while raised bog soils and transition bog soils differed the least. Statistically significant dif...

  13. Visual soil assessment: field guide for cropping

    OpenAIRE

    Shepherd, Graham

    2000-01-01

    Visual assessments provide an immediate diagnostic tool to evaluate soil quality, as many physical, biological (and to a lesser degree chemical) soil characteristics show up as visual characteristics. Results are easy to interpret and understand. The Visual Soil Assessment (VSA) method has been developed to help land managers assess soil quality easily, quickly, reliably and cheaply on a paddock scale. It requires little equipment, training or technical skills. Part I, “VSA of soil qu...

  14. Brazilian Cerrado Soil Actinobacteria Ecology

    Directory of Open Access Journals (Sweden)

    Monique Suela Silva

    2013-01-01

    Full Text Available A total of 2152 Actinobacteria strains were isolated from native Cerrado (Brazilian Savannah soils located in Passos, Luminárias, and Arcos municipalities (Minas Gerais State, Brazil. The soils were characterised for chemical and microbiological analysis. The microbial analysis led to the identification of nine genera (Streptomyces, Arthrobacter, Rhodococcus, Amycolatopsis, Microbacterium, Frankia, Leifsonia, Nakamurella, and Kitasatospora and 92 distinct species in both seasons studied (rainy and dry. The rainy season produced a high microbial population of all the aforementioned genera. The pH values of the soil samples from the Passos, Luminárias, and Arcos regions varied from 4.1 to 5.5. There were no significant differences in the concentrations of phosphorus, magnesium, and organic matter in the soils among the studied areas. Samples from the Arcos area contained large amounts of aluminium in the rainy season and both hydrogen and aluminium in the rainy and dry seasons. The Actinobacteria population seemed to be unaffected by the high levels of aluminium in the soil. Studies are being conducted to produce bioactive compounds from Actinobacteria fermentations on different substrates. The present data suggest that the number and diversity of Actinobacteria spp. in tropical soils represent a vast unexplored resource for the biotechnology of bioactives production.

  15. Photodissolution of soil organic matter

    Science.gov (United States)

    Mayer, L.M.; Thornton, K.R.; Schick, L.L.; Jastrow, J.D.; Harden, J.W.

    2012-01-01

    Sunlight has been shown to enhance loss of organic matter from aquatic sediments and terrestrial plant litter, so we tested for similar reactions in mineral soil horizons. Losses of up to a third of particulate organic carbon occurred after continuous exposure to full-strength sunlight for dozens of hours, with similar amounts appearing as photodissolved organic carbon. Nitrogen dissolved similarly, appearing partly as ammonium. Modified experiments with interruption of irradiation to include extended dark incubation periods increased loss of total organic carbon, implying remineralization by some combination of light and microbes. These photodissolution reactions respond strongly to water content, with reaction extent under air-dry to fully wet conditions increasing by a factor of 3-4 fold. Light limitation was explored using lamp intensity and soil depth experiments. Reaction extent varied linearly with lamp intensity. Depth experiments indicate that attenuation of reaction occurs within the top tens to hundreds of micrometers of soil depth. Our data allow only order-of-magnitude extrapolations to field conditions, but suggest that this type of reaction could induce loss of 10-20% of soil organic carbon in the top 10. cm horizon over a century. It may therefore have contributed to historical losses of soil carbon via agriculture, and should be considered in soil management on similar time scales. ?? 2011 Elsevier B.V.

  16. Phytoremediation of petroleum polluted soil

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Zhang Zhongzhi; Su Youming; He Wei; He Feng; Song Hongguang

    2008-01-01

    An experimental study of the rhizosphere effect on phytoremediation of petroleum polluted soil was carried out with three species of grasses,namely Pannicum,Eleusine indica (L.) Gaerth,and Tall Fescue.After a period of 150 days,this pot experiment showed that the rhizosphere of these three species accelerated the degradation of petroleum hydrocarbons to different extents.The results showed that the number of microorganisms in the rhizosphere increased by three orders of magnitude.The induction of the plant rhizosphere and the coercion influence of petroleum changed the species and activity of microorganisms.The degradation of petroleum hydrocarbons in the rhizosphere was 3-4 times that in unplanted soil.The dehydrogenase activity in the rhizosphere was 1.61-2.20 times that in unplanted soil,but the catalase activity was 0.90-0.93 times that in unplanted soil,and soil moisture content increased by 5% compared with the unplanted soil.

  17. Nuclear forensics: Soil content

    Energy Technology Data Exchange (ETDEWEB)

    Beebe, Merilyn Amy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-31

    Nuclear Forensics is a growing field that is concerned with all stages of the process of creating and detonating a nuclear weapon. The main goal is to prevent nuclear attack by locating and securing nuclear material before it can be used in an aggressive manner. This stage of the process is mostly paperwork; laws, regulations, treaties, and declarations made by individual countries or by the UN Security Council. There is some preliminary leg work done in the form of field testing detection equipment and tracking down orphan materials; however, none of these have yielded any spectacular or useful results. In the event of a nuclear attack, the first step is to analyze the post detonation debris to aid in the identification of the responsible party. This aspect of the nuclear forensics process, while reactive in nature, is more scientific. A rock sample taken from the detonation site can be dissolved into liquid form and analyzed to determine its chemical composition. The chemical analysis of spent nuclear material can provide valuable information if properly processed and analyzed. In order to accurately evaluate the results, scientists require information on the natural occurring elements in the detonation zone. From this information, scientists can determine what percentage of the element originated in the bomb itself rather than the environment. To this end, element concentrations in soils from sixty-nine different cities are given, along with activity concentrations for uranium, thorium, potassium, and radium in various building materials. These data are used in the analysis program Python.

  18. Soil Degradation and Soil Quality in Western Europe: Current Situation and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Iñigo Virto

    2014-12-01

    Full Text Available The extent and causes of chemical, physical and biological degradation of soil, and of soil loss, vary greatly in different countries in Western Europe. The objective of this review paper is to examine these issues and also strategies for soil protection and future perspectives for soil quality evaluation, in light of present legislation aimed at soil protection. Agriculture and forestry are the main causes of many of the above problems, especially physical degradation, erosion and organic matter loss. Land take and soil sealing have increased in recent decades, further enhancing the problems. In agricultural land, conservation farming, organic farming and other soil-friendly practices have been seen to have site-specific effects, depending on the soil characteristics and the particular types of land use and land users. No single soil management strategy is suitable for all regions, soil types and soil uses. Except for soil contamination, specific legislation for soil protection is lacking in Western Europe. The Thematic Strategy for Soil Protection in the European Union has produced valuable information and has encouraged the development of networks and databases. However, soil degradation is addressed only indirectly in environmental policies and through the Common Agricultural Policy of the European Union, which promotes farming practices that support soil conservation. Despite these efforts, there remains a need for soil monitoring networks and decision-support systems aimed at optimization of soil quality in the region. The pressure on European soils will continue in the future, and a clearly defined regulatory framework is needed.

  19. Relationship Between Soil Properties and Different Fractions of Soil Hg

    Institute of Scientific and Technical Information of China (English)

    WUHONGTAO; YUGUIFEN; 等

    2001-01-01

    Correlation and path analysis methods were used to study the relationship between soil properties and the distribution of different soil Hg fractions with nine representative soils from Chongqing,China,Results showed that clay(<2m) could increase water-soluble Hg(r=0.700*).Soil organic matter (OM) could enhance the increase of elemental Hg(r=0.674*),The higher the base saturation percentage (BSP) ,the more the residual Hg(R=0.684*) .Organic Hg,the sum of said-soluble organic He and alkali-soluble Hg,was positively affected by silt(2-20μm)but negatively affected by pH,with the direct path coefficients amounting to 1.0487 and 0.5121,respectively .The positive effect of OM and negative effect of BSP on organic Hg were the most significant ,with the direct path coefficients being 0.7614 and -0.8527,respectively. The indirect effect of clay(<2μm) iva BSP (path coefficient=0.4186) was the highest,showing that the real influencing factor in the effect of clay(<2μm) via BSP (path coefficient=0.4186) was the highest,showing that the real influencing factor in the effect of clay(<2μm) on acid-soluble organic Hw was BSP.since the available Hg fraction,water-soluble Hg,was positively affected by soil clay content,and the quite immobile and not bioavailable residual Hg by soil BSP,suitable reduction of clay content and increase of BSP would be of much help to reduce the Hg availability and Hg activity in Hg-contaminated soils.

  20. Soil hydrologic characterization for modeling large scale soil remediation protocols

    Science.gov (United States)

    Romano, Nunzio; Palladino, Mario; Di Fiore, Paola; Sica, Benedetto; Speranza, Giuseppe

    2014-05-01

    In Campania Region (Italy), the Ministry of Environment identified a National Interest Priority Sites (NIPS) with a surface of about 200,000 ha, characterized by different levels and sources of pollution. This area, called Litorale Domitio-Agro Aversano includes some polluted agricultural land, belonging to more than 61 municipalities in the Naples and Caserta provinces. In this area, a high level spotted soil contamination is moreover due to the legal and outlaw industrial and municipal wastes dumping, with hazardous consequences also on the quality of the water table. The EU-Life+ project ECOREMED (Implementation of eco-compatible protocols for agricultural soil remediation in Litorale Domizio-Agro Aversano NIPS) has the major aim of defining an operating protocol for agriculture-based bioremediation of contaminated agricultural soils, also including the use of crops extracting pollutants to be used as biomasses for renewable energy production. In the framework of this project, soil hydrologic characterization plays a key role and modeling water flow and solute transport has two main challenging points on which we focus on. A first question is related to the fate of contaminants infiltrated from stormwater runoff and the potential for groundwater contamination. Another question is the quantification of fluxes and spatial extent of root water uptake by the plant species employed to extract pollutants in the uppermost soil horizons. Given the high variability of spatial distribution of pollutants, we use soil characterization at different scales, from field scale when facing root water uptake process, to regional scale when simulating interaction between soil hydrology and groundwater fluxes.

  1. Pyrosequencing-based assessment of soil bacterial communities within soil aggregates: Linking structure to C storage

    Science.gov (United States)

    Alterations in soil structural properties created by agricultural management practices have a significant influence on soil aggregation, which manages the chemical and physical heterogeneity of soil properties, and, consequently, the distribution of microorganisms and their activity among aggregates...

  2. The soil management assessment framework: A potential soil health assessment tool

    Science.gov (United States)

    The Soil Management Assessment Framework (SMAF) was developed in the 1990s utilizing Systems Engineering and Ecology experiences with scoring functions to normalize disparate soil physical, chemical, and biological indicator data representing critical properties and processes associated with soil qu...

  3. [Response of mineralization of dissolved organic carbon to soil moisture in paddy and upland soils in hilly red soil region].

    Science.gov (United States)

    Chen, Xiang-Bi; Wang, Ai-Hua; Hu, Le-Ning; Huang, Yuan; Li, Yang; He, Xun-Yang; Su, Yi-Rong

    2014-03-01

    Typical paddy and upland soils were collected from a hilly subtropical red-soil region. 14C-labeled dissolved organic carbon (14C-DOC) was extracted from the paddy and upland soils incorporated with 14C-labeled straw after a 30-day (d) incubation period under simulated field conditions. A 100-d incubation experiment (25 degrees C) with the addition of 14C-DOC to paddy and upland soils was conducted to monitor the dynamics of 14C-DOC mineralization under different soil moisture conditions [45%, 60%, 75%, 90%, and 105% of the field water holding capacity (WHC)]. The results showed that after 100 days, 28.7%-61.4% of the labeled DOC in the two types of soils was mineralized to CO2. The mineralization rates of DOC in the paddy soils were significantly higher than in the upland soils under all soil moisture conditions, owing to the less complex composition of DOC in the paddy soils. The aerobic condition was beneficial for DOC mineralization in both soils, and the anaerobic condition was beneficial for DOC accumulation. The biodegradability and the proportion of the labile fraction of the added DOC increased with the increase of soil moisture (45% -90% WHC). Within 100 days, the labile DOC fraction accounted for 80.5%-91.1% (paddy soil) and 66.3%-72.4% (upland soil) of the cumulative mineralization of DOC, implying that the biodegradation rate of DOC was controlled by the percentage of labile DOC fraction.

  4. Bioindication in Urban Soils in Switzerland

    Science.gov (United States)

    Amossé, J.; Le Bayon, C.; Mitchell, E. A. D.; Gobat, J. M.

    2012-04-01

    Urban development leads to profound changes in ecosystem structure (e.g. biodiversity) and functioning (e.g. ecosystem services). While above-ground diversity is reasonably well studied much less is known about soil diversity, soil processes and more generally soil health in urban settings. Soil invertebrates are key actors of soil processes at different spatial and temporal scales and provide essential ecosystem services. These functions may be even more vital in stressed environments such as urban ecosystems. Despite the general recognition of the importance of soil organisms in ecosystems, soil trophic food webs are still poorly known and this is especially the case in urban settings. As urban soils are characterised by high fragmentation and stress (e.g. drought, pollution) the structure and functioning of soil communities is likely to be markedly different from that of natural soils. It is for example unclear if earthworms, whose roles in organic matter transformation and soil structuration is well documented in natural and semi-natural soils, are also widespread and active in urban soils. Bioindication is a powerful tool to assess the quality of the environment. It is complementary to classical physicochemical soil analysis or can be used as sole diagnostic tool in cases where these analyses cannot be performed. However little is known about the potential use of bioindicators in urban settings and especially it is unclear if methods developped in agriculture can be applied to urban soils. The development of reliable methods for assessing the quality of urban soils has been identified as a priority for policy making and urban management in Switzerland, a high-urbanized country. We therefore initiated a research project (Bioindication in Urban Soil - BUS). The project is organised around four parts: (i) typology of urban soils in a study Region (Neuchâtel), (ii) sampling of soil fauna and analysis of soil physicochemical properties, (iii) comparison of the

  5. Simulation of Soil Water Content Variability in a Heavy Clay Soil under Contrasting Soil Managements

    Science.gov (United States)

    Pedrera, A.; Vanderlinden, K.; Martínez, G.; Espejo, A. J.; Giráldez, J. V.

    2012-04-01

    Soil water content (SWC) is a key variable for numerous physical, chemical and biological processes that take place at or near the soil surface. Understanding the spatial and temporal variability of SWC at the field scale is of prime importance for implementing efficient measurement strategies in applications. The aim of this study was to characterize the spatial and temporal variation of gravimetric SWC in a heavy clay soil, in a wheat-sunflower-legume rotation under conventional (CT) and no-till (NT) using a simple water balance model. An experimental field in SW Spain, where conventional (CT) and no-till (NT) management of a heavy clay soil are being compared since 1983, was sampled for gravimetric SWC on 38 occasions during 2008 and 2009. Topsoil clay content across the six plots was on average 55%, with a standard deviation of 2.7%. The soil profile was sampled at 54 locations, evenly distributed over the three CT and NT plots, at depths of 0-10, 25-35, and 55-65 cm. Topsoil water retention curves (SWRC) were determined in the laboratory on undisturbed soil samples from each of the 54 locations. A weather station recorded daily precipitation and evapotranspiration, as calculated by the Penman-Monteith FAO equation. The water balance was calculated using the Thornthwaite-Mather model with a daily time step. Three parameters, water holding capacity, and water evaporation corrector coefficients for each of the two years, were inversely estimated at the 54 SWC observation points and probability density functions were identified. Spatial variability of SWC was estimated using a Monte Carlo approach, and simulated and observed variability were compared. This Monte Carlo scheme, using a simple water balance model with only three parameters, was found to be useful for evaluating the influence of soil management on the variability of SWC in heavy clay soils.

  6. Modeling soil moisture memory in savanna ecosystems

    Science.gov (United States)

    Gou, S.; Miller, G. R.

    2011-12-01

    Antecedent soil conditions create an ecosystem's "memory" of past rainfall events. Such soil moisture memory effects may be observed over a range of timescales, from daily to yearly, and lead to feedbacks between hydrological and ecosystem processes. In this study, we modeled the soil moisture memory effect on savanna ecosystems in California, Arizona, and Africa, using a system dynamics model created to simulate the ecohydrological processes at the plot-scale. The model was carefully calibrated using soil moisture and evapotranspiration data collected at three study sites. The model was then used to simulate scenarios with various initial soil moisture conditions and antecedent precipitation regimes, in order to study the soil moisture memory effects on the evapotranspiration of understory and overstory species. Based on the model results, soil texture and antecedent precipitation regime impact the redistribution of water within soil layers, potentially causing deeper soil layers to influence the ecosystem for a longer time. Of all the study areas modeled, soil moisture memory of California savanna ecosystem site is replenished and dries out most rapidly. Thus soil moisture memory could not maintain the high rate evapotranspiration for more than a few days without incoming rainfall event. On the contrary, soil moisture memory of Arizona savanna ecosystem site lasts the longest time. The plants with different root depths respond to different memory effects; shallow-rooted species mainly respond to the soil moisture memory in the shallow soil. The growing season of grass is largely depended on the soil moisture memory of the top 25cm soil layer. Grass transpiration is sensitive to the antecedent precipitation events within daily to weekly timescale. Deep-rooted plants have different responses since these species can access to the deeper soil moisture memory with longer time duration Soil moisture memory does not have obvious impacts on the phenology of woody plants

  7. Impact of soil management practices on soil fertility and disease suppressiveness

    OpenAIRE

    Tamm, Lucius; Bruns, Christian; Leifert, Carlo; Fuchs, Jacques G.; Thürig, Barbara; Specht, Nicole; Fliessbach, Andreas

    2006-01-01

    Soil management practices are targeted to provide adequate crop nutrition and to ensure durable soil fertility and to avoid negative environmental impacts. Soil management also aims to reduce pest and disease pressure on crops. Organic farming is believed to increase soil suppressiveness towards soil-borne diseases as well aerial diseases. In this paper we will discuss the potential of soil manage-ment as a tool to improve disease suppressiveness in practice.

  8. 软土地区大覆土明挖隧道沉降变形规律研究%Settlement Deformation Regularity of Large Covering Soil Open Excavation Tunnel in Soft Soil Area

    Institute of Scientific and Technical Information of China (English)

    刘浩

    2016-01-01

    针对软土地基大覆土明挖隧道的工程特点,考虑深基坑开挖卸荷导致下卧土层压缩特性较大变化以及软弱地基加固对隧道沉降产生整体影响等诸多因素,采用二维有限元计算,对有无地基处理情况下,隧道修建和覆土回填对隧道沉降的影响规律进行分析,研究结果表明:基础桩的施加使得结构沉降减小了约90%。在软土地区,在原有软弱地基上修建隧道,若不进行地基处理,会引起较大沉降和不均匀沉降,造成结构受力偏大甚至产生裂缝危害结构安全。而在这种软弱地基中,因基础桩与底板相互接触,同时基础桩底部插入了中风化花岗岩层,故隧道所受力可通过基础桩直接传递到持力层,大大减小了软弱土层的压缩,从而保证结构安全。%For the engineering characteristics of large covering soil open excavation tunnel in soft soil foundation,and con-sidering many factors such as a large change of solum compression features caused by unloading of deep foundation pit excava-tion,and the overall impact of soft foundation reinforcement on the tunnel settlement.By adopting the method of two-dimen-sional finite element calculation,we analyze the influence law of tunnel construction and overlying soil backfill on tunnel set-tlement with or without foundation treatment.The results show that the structure settlement is reduced by 90% with the in-creasing foundation pile.In soft soil area,the tunnel is built on the existing soft foundation,it will cause a larger and uneven settlement without foundation treatment,and then a bigger structure stress or even cracks endanger the safety of structure will be caused.In the soft foundation,the overlying load of tunnel can be directly transferred to the bearing layer on the basis of the mutual contact between foundation pile and bottom board as well as the bottom of foundation pile is inserted into moderate-ly weathered granitic

  9. Human land-use and soil change

    Science.gov (United States)

    Wills, Skye A.; Williams, Candiss O.; Duniway, Michael C.; Veenstra, Jessica; Seybold, Cathy; Pressley, DeAnn

    2017-01-01

    Soil change refers to the alteration of soil and soil properties over time in one location, as opposed to soil variability across space. Although soils change with pedogensis, this chapter focuses on human caused soil change. Soil change can occur with human use and management over long or short time periods and small or large scales. While change can be negative or positive; often soil change is observed when short-term or narrow goals overshadow the other soil’s ecosystem services. Many soils have been changed in their chemical, physical or biological properties through agricultural activities, including cultivation, tillage, weeding, terracing, subsoiling, deep plowing, manure and fertilizer addition, liming, draining, and irrigation. Assessing soil change depends upon the ecosystem services and soil functions being evaluated. The interaction of soil properties with the type and intensity of management and disturbance determines the changes that will be observed. Tillage of cropland disrupts aggregates and decreases soil organic carbon content which can lead to decreased infiltration, increased erosion, and reduced biological function. Improved agricultural management systems can increase soil functions including crop productivity and sustainability. Forest management is most intensive during harvesting and seedling establishment. Most active management in forests causes disturbance of the soil surface which may include loss of forest floor organic materials, increases in bulk density, and increased risk of erosion. In grazing lands, pasture management often includes periods of biological, chemical and physical disturbance in addition to the grazing management imposed on rangelands. Grazing animals have both direct and indirect impacts on soil change. Hoof action can lead to the disturbance of biological crusts and other surface features impairing the soil’s physical, biological and hydrological function. There are clear feedbacks between vegetative systems

  10. Stocks of organic carbon in Estonian soils

    Directory of Open Access Journals (Sweden)

    Kõlli, Raimo

    2009-06-01

    Full Text Available The soil organic carbon (SOC stocks (Mg ha–1 ofautomorphic mineral (9 soil groups, hydromorphic mineral (7, and lowland organic soils (4 are given for the soil cover or solum layer as a whole and also for its epipedon (topsoil layer. The SOC stocks for forest, arable lands, and grasslands and for the entire Estonian soil cover were calculated on the basis of the mean SOC stock and distribution area of the respective soil type. In the Estonian soil cover (42 400 km2, a total of 593.8 ± 36.9 Tg of SOC is retained, with 64.9% (385.3 ± 27.5 Tg in the epipedon layer (O, H, and A horizons and 35.1% in the subsoil (B and E horizons. The pedo-ecological regularities of SOC retention in soils are analysed against the background of the Estonian soil ordination net.

  11. Soil Water and Temperature System (SWATS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Bond, D

    2005-01-01

    The soil water and temperature system (SWATS) provides vertical profiles of soil temperature, soil-water potential, and soil moisture as a function of depth below the ground surface at hourly intervals. The temperature profiles are measured directly by in situ sensors at the Central Facility and many of the extended facilities of the SGP climate research site. The soil-water potential and soil moisture profiles are derived from measurements of soil temperature rise in response to small inputs of heat. Atmospheric scientists use the data in climate models to determine boundary conditions and to estimate the surface energy flux. The data are also useful to hydrologists, soil scientists, and agricultural scientists for determining the state of the soil.

  12. Colloid Release From Differently Managed Loess Soil

    DEFF Research Database (Denmark)

    Vendelboe, Anders Lindblad; Schjønning, Per; Møldrup, Per

    2012-01-01

    of the total clay not associated with organic matter. No significant difference in release rate was found for air-dry aggregates. The low-carbon soils initially had a higher content of WSA but were more susceptible to disaggregation than the high-carbon soils. Furthermore, the application of NPK fertilizer had......The content of water-dispersible colloids (WDC) in a soil can have a major impact on soil functions, such as permeability to water and air, and on soil strength, which can impair soil fertility and workability. In addition, the content of WDC in the soil may increase the risk of nutrient loss...... and of colloid-facilitated transport of strongly sorbing compounds. In the present study, soils from the Bad Lauchsta¨dt longterm static fertilizer experiment with different management histories were investigated to relate basic soil properties to the content of WDC, the content of water-stable aggregates (WSA...

  13. Managing for soil health can suppress pests

    Directory of Open Access Journals (Sweden)

    Amanda Hodson

    2016-08-01

    Full Text Available A “healthy” soil can be thought of as one that functions well, both agronomically and ecologically, and one in which soil biodiversity and crop management work in synergy to suppress pests and diseases. UC researchers have pioneered many ways of managing soil biology for pest management, including strategies such as soil solarization, steam treatment and anaerobic soil disinfestation, as well as improvements on traditional methods, such as reducing tillage, amending soil with organic materials, and cover cropping. As managing for soil health becomes more of an explicit focus due to restrictions on the use of soil fumigants, integrated soil health tests will be needed that are validated for use in California. Other research needs include breeding crops for disease resistance and pest suppressive microbial communities as well as knowledge of how beneficial organisms influence plant health.

  14. Speciation of Pb in industrially polluted soils

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Ottosen, Lisbeth M.; Pedersen, Anne Juul

    2006-01-01

    This study was aimed at elucidating the importance of original Pb-speciation versus soil-characteristics to mobility and distribution of Pb in industrially polluted soils. Ten industrially polluted Danish surface soils were characterized and Pb speciation was evaluated through SEM-EDX studies......, examination of pH-dependent desorption, distribution in grain-size fractions and sequential extraction. Our results show that the first factors determining the speciation of Pb in soil are: (1) the stability of the original speciation and (2) the contamination level, while soil characteristics...... are of secondary importance. In nine of ten soils Pb was concentrated strongly in the soil fines (soils, particles with a highly concentrated Pb-content were observed during SEM-EDX. In eight of the soils, the particles contained various Pb-species with aluminum/iron, phosphate, sulfate...

  15. Spatial and temporal variability of soil electrical conductivity related to soil moisture

    Directory of Open Access Journals (Sweden)

    José Paulo Molin

    2013-02-01

    Full Text Available Soil electrical conductivity (ECa is a soil quality indicator associated to attributes interesting to site-specific soil management such as soil moisture and texture. Soil ECa provides information that helps guide soil management decisions, so we performed spatial evaluation of soil moisture in two experimental fields in two consecutive years and modeled its influence on soil ECa. Soil ECa, moisture and clay content were evaluated by statistical, geostatistical and regression analyses. Semivariogram models, adjusted for soil moisture, had strong spatial dependence, but the relationship between soil moisture and soil ECa was obtained only in one of the experimental fields, where soil moisture and clay content range was higher. In this same field, coefficients of determinations between soil moisture and clay content were above 0.70. In the second field, the low soil moisture and clay content range explain the absence of a relationship between soil ECa and soil moisture. Data repetition over the years, suggested that ECa is a qualitative indicator in areas with high spatial variability in soil texture.

  16. Continuous Mapping of Soil pH Using Digital Soil Mapping Approach in Europe

    OpenAIRE

    Ciro Gardi; Yusuf Yigini

    2012-01-01

    Soil pH is one of the most important chemical parameters of soil, playing an essential role on the agricultural production and on the distribution of plants and soil biota communities. It is the expression of soil genesis that in turns is a function of soil forming factors and influences all the chemical, physical and biological processes that occur in the soil. Thus it shapes the entire soil ecosystem. Due to any of the above reasons, mapping of soil pH becomes very important to provide harm...

  17. Impacts of Soil Moisture Content and Vegetation on Shear Strength of Unsaturated Soil

    Institute of Scientific and Technical Information of China (English)

    YANG Yong-hong; ZHANG Jian-guo; ZHANG Jian-hui; LIU Shu-zhen; WANG Cheng-hua; XIAO Qing-hua

    2005-01-01

    It is analyzed that the impacts of vegetation type and soil moisture content on shear strength of unsaturated soil through direct shearing tests for various vegetation types, different soil moisture contents and different-depth unsaturated soil. The results show that the cohesion of unsaturated soil changes greatly, and the friction angle changes a little with soil moisture content. It is also shown that vegetation can improve shear strength of unsaturated soil, which therefore provides a basis that vegetation can reinforce soil and protect slopes.

  18. Soil-borne microorganisms and soil-type affect pyrrolizidine alkaloids in Jacobaea vulgaris

    OpenAIRE

    2009-01-01

    Secondary metabolites like pyrrolizidine alkaloids (PAs) play a crucial part in plant defense. We studied the effects of soil-borne microorganisms and soil-type on pyrrolizidine alkaloids in roots and shoots of Jacobaea vulgaris. We used clones of two genotypes from a dune area (Meijendel), propagated by tissue culture and grown on two sterilized soils and sterilized soils inoculated with 5% of non-sterilized soil of either of the two soil-types. Soil-borne microorganisms and soil-type affect...

  19. Clay-illuvial soils in the Polish and international soil classifications

    Directory of Open Access Journals (Sweden)

    Kabała Cezary

    2015-12-01

    Full Text Available Soil with a clay-illuvial subsurface horizon are the most widespread soil type in Poland and significantly differ in morphology and properties developed under variable environmental conditions. Despite the long history of investigations, the rules of classification and cartography of clay-illuvial soils have been permanently discussed and modified. The distinction of clay-illuvial soils into three soil types, introduced to the Polish soil classification in 2011, has been criticized as excessively extended, non-coherent with the other parts and rules of the classification, hard to introduce in soil cartography and poorly correlated with the international soil classifications. One type of clay-illuvial soils (“gleby płowe” was justified and recommended to reintroduce in soil classification in Poland, as well as 10 soil subtypes listed in a hierarchical order. The subtypes may be combined if the soil has diagnostic features of more than one soil subtypes. Clear rules of soil name generalization (reduction of subtype number for one soil were suggested for soil cartography on various scales. One of the most important among the distinguished soil sub-types are the “eroded” or “truncated” clay-illuvial soils.

  20. Soil Degradation and Soil Value in Slovakia – Two Problems with Common Denominator

    Directory of Open Access Journals (Sweden)

    Radoslav Bujnovský

    2011-03-01

    Full Text Available Soil use is oft en accompanied by its degradation. Immediate reason of soil degradation in agriculture is the non-respecting the principles of good agricultural practice. Giving long-term precedence to production function over remaining ecological ones as well as supporting the land consumption for economy development by governmental bodies are next reasons of soil degradation and mirror the societal values and priorities.Soil provides many services that in soil science are defined as soil functions. Besides biomass production the soil provides ecological and socio-economic functions. Use of soil and its functions is closely linked to soil ecological, societal and economic values. Preference to economic interests together with reluctance to search compromise solutions is oft en manifesting in soil degradation. Economic valuation of soil and its ecological functions is considered a possible way for improvement of soil protection especially in modification of soil price at its permanent consumption. In spite of that financial values can not be used as a base for forming of ethical values, which are imminently connected with human approach towards soil and its degradation, and which are essentially needed by global society. Ethical human values, based on basic beliefs and convictions, influence of human attitude to the soil, and they influence on soil use can be considered as common denominator of soil degradation and soil value, respectively.