Sample records for geotextiles

  1. Fatigue Properties of the Two Composite Geotextiles

    QIAN Cheng; CHU Cai-yuan


    In order to make clear the service life of the two composite geotextiles, their fatigue and dynamic creep properties were tested and compared. The experimental results show that the dynamic creep deformations of adhesive bonded composite geotextiles are lower than those of needle -punched composite geotextiles and the former also have longer fatigue lifetime than the latter.As during the making process, the component parts of adhesive bonded composite geotextiles are not damaged by any factors which in case make their tensile strength higher than those of the needle- punched composite geotextiles. At the end of the paper, a proper explanation was given to this phenomenon.

  2. Geotextiles in Flexible Pavement Construction

    Alungbe, Gabriel D.


    People everywhere in the developed world regularly drive on paved roads. Learning about the construction techniques and materials used in paving benefits technology and construction students. This article discusses the use of geosynthetic textiles in pavement construction. It presents background on pavements and describes geotextiles and drainage…

  3. Geotextile Tube Structures Guidelines for Contract Specifications


    Method ASTM D 4354 (1999) Sampling of Geosynthetics for Testing ASTM D 4355 (1999) Deterioration of Geotextiles from Exposure to Ultraviolet Light... Geosynthetics ASTM D 4833 (2000) Index Puncture Resistance of Geotextiles, Geomembranes and Related Products ASTM D 4873 (2001) Guide for...Identification, Storage, and Handling of Geosynthetic Rolls ASTM D 4884 (1996) Strength of Sewn or Thermally Bonded Seams of Geotextiles ASTM D 5261 (1992

  4. Slope reinforcement design using geotextiles and geogrids

    Setser, Darrell M.


    A geotextile is defined by ASTM as: any permeable textile material used with foundation, soil, rock, earth, or any other geotechnical engineering related material, as a integral part of a man-made project, structure, or system. A geogrid is defined as: any geotextile-related material used in a similar manner to geotextiles. They are usually made of plastic, but can be metal or wood. Geotextiles and geogrids are collectively referred to as geosynthetics in this paper. Geosynthetic reinforcement of slopes is a relatively new option available to the civil engineer. Slope angles can be increased and 'poor' soil can be used to construct economical soil-geosynthetic facilities. Uncertainties exist in the complex interaction between the soil and the geosynthetic but there are numerous procedures which ignore this in the design. The design procedures available may be conservative yet still may be an economical alternative when compared to more conventional options.

  5. Performance of geotextiles in landfills covers

    Reitz, L.J.; Holtz, R.D.


    As part of the research into the performance of geotextiles in landfill covers, 14 test pits were excavated in five landfill covers constructed between 1988 and 1992 in Washington State. Materials used in the drainage system were examined and documented. Specimens of geotextiles (all 8 oz/yd{sup 2}, needle punched nonwovens) as well as samples of the vegetative and sand drainage soils, were obtained for laboratory analyses. Laboratory tests indicated that the geotextiles satisfactorily performed their intended filtration function. No apparent migration of fines into the drainage layer was detected. The degree of clogging was evaluated by performing permittivity tests on specimens of the exhumed geotextiles, as retrieved and after washing. Washing typically resulted in permittivity increases on the order of 30 to 90 percent.

  6. The role of geotextiles in geosynthetic applications

    Anandjiwala, RD


    Full Text Available Conference Accra, Ghana 18 – 20 November 2013 The Role of Geotextiles in Geosynthetic Applications R. D. Anandjiwala1,2 1Chief Researcher and Research Group Leader: Nonwovens and Composites Research Group, Polymers and Composites Competence Area... GhIGS GeoAfrica 2013 Conference Accra, Ghana 18 – 20 November 2013 to fulfil the criteria demanded by the specific end-use. For instance, the geotextile products used in rail track construction must possess high strength, excellent filtration...

  7. Engineering geotextile tubes to be used in dyke construction

    ZHU Yuan-sheng


    Geotextile tube technology has been increasingly used in dykes. In this work reinforcement theory and circle method were employed to examine the allowable tensile limit of the geotextile tube and the stability factor of the slip surface of the dyke. The formulas to calculate the layer-to-layer spacing and size of geotextile tubes applied to double prism dykes were deduced. The application of these formulas was illustrated by several examples. The calculation results indicate that unequal spacing arrangement is more economical than equal spacing and the layer number of required geotextile tubes decreases with the increase of allowable tensile strength of the geotextile.

  8. Shape and Mechanical Behavior of Geotextile Tubes

    ZHANG Wen-bin; TAN Jia-hua


    Nowadays, geotextile tubes hydraulically filled with dredged materials have been used in the application of cofferdam,sea reclamation and deepwater channel regulation in China.The shape and mechanical behaviors during the process of filling, consolidation and stacked are one of the main problems concerned by designers and researchers. This paper uses the method of elliptic integrals to study the behaviors of filling and deduces the regressive formulas of shape features and circumferential tension. The results show that the proposal regressive formulas are only the function of pressure at bottom;they are very convenient and suitable for the filling design.When the filling materials are sandy, the shape and mechanical behaviors nearly remain during the process of consolidation. The behaviors of stacked geotextile tubes are very complex, because they are involved in the properties of the filling material,geotextile and foundation. Using the commercial finite element analysis program ABAQUS, this paper establishes the entire 2-D finite element load model to investigate, which include the part of filling material, geotextile and foundation. The numerical results suggest that the maximum circumferential tension varies with the properties of filling materials and foundations, whereas the largest tensile force occurs during the filling process.

  9. Jute geotextiles and their applications in civil engineering

    Sanyal, Tapobrata


    This book presents a first-of-its-kind exposition on the emerging technology of jute fibre geotextiles. The book covers the characteristics of jute fibre and jute yarns, types and functions of jute geotextiles, and the mechanism of control of surficial soil with jute geotextiles. The content also includes applications such as the mechanisms of functioning of jute geotextiles in strengthening road sub-grade and controlling river bank erosion, stabilization of earthen embankments, management of settlement of railway tracks, and consolidation of soft soil by use of pre-fabricated vertical jute drains (PVJD). Geotextile standards, properties and test methods, variants of jute geotextiles, economical and environmental advantages in different applications are covered along with a few case studies. A chapter on soil basics is included to enable clearer understanding of soil mechanisms. The book can be used as a reference work or as primary or supporting text for graduate and professional coursework. It will also pro...

  10. Geotextiles - great future prospects for a new material



    Geotextiles is the collective term used for a large number of geotechnical synthetic materials. Geotextiles fulfill hydraulic and/or mechanical functions in civil engineering. Their respective functions depend on the types of fibers they are composed of, the production processes they have gone through, and on their application and uses. While the hydraulic functions of geotextiles (which can either be of the woven or nonwoven kind) consist in draining and filtration their mechanical functions for example comprise separation, protection, reinforcement and leveling. They are used for drainages, building construction and foundations, unpaved roads, hills and embankments, railroad constructions, erosion control, and different special purposes. Geotextiles are characterized by their constant tensile strength, constant resistance to tearing, omnidirecvtional extensibility, their high-bulking structures, high interlacing strength, and full widths. The paper deals with the manufacturing of geotextiles, aerodynamic weaving, stabilization through needle felting processes, glass fiber textiles, and filament spunbonds and concludes with a number of practical examples of geotextile uses.


    LUCA Cristinel


    Full Text Available This work was performed in order to assess the functionality of geotextiles used in road construction. To increase the quality of road works requires the use of geotextiles in their structure. Depending on the role and the benefits they offer, geotextiles have a number of physical properties, hydraulic, endurance and optimal characteristics regarding their degradation. Geotextile properties were identified and divided according to their characteristics area. Thus, there were obtained textile properties oriented towards geotextiles and properties geared to the application field respectively reinforcement, drainage, and filtration. Value engineering works at the level of constructive product conception and production. The instrumentation is done by functional analysis, value functions and design or redesign of geotextile based on the necessary functions. Systematic research method allowed geotextiles dimensioning functions in order to obtain products in terms of quality, reliability and maximum operational performance. Functions obtained from the analysis are appropriate for a single property. After obtaining the set of decisions was possible functions geotextiles hierarchy after the significance of their use. Establishing the importance of the coefficients or characteristics hierarchy after their weight requires the comparison of the features between them and grading them in proportion to their degree of importance. The ranking of these functions is beneficial when designing or redesigning geotextiles.

  12. Application of Geotextile Bag Dehydrated Soil to Dike Construction

    朱平; 闫澍旺; 刘润


    Using geotextile bag dehydrated soil to construct dikes for land reclamation to substitute conventional straw bags is an urgent need in Tianjin New Harbor, China. This paper introduces the method to build a dike for hydraulic filling. The soil for filling the geotextile bags was tested in wave trench; the stress developed during construction was calculated by establishing a numerical model and compared with the tensile strength of the geotextile; the stability and settlement of the dike were estimated by performing centrifuge tests. Through this study, the following information was obtained: 1) The cohesionless silt with plasticity index less than 10 is suitable for filling the geotextile bags. The geotextile bag dehydrated soil consolidated very quickly even under the action of wave force. 2) A numerical model was devised to find the limit injection height and to calculate the tensile stress developed in the geotextile bags when they were piled up to form the dike. The calculated stress was compared with the strength of the geotextile, showing that the design is reasonably safe. 3) Centrifuge test results show that the designed dike will be stable and the settlement of dike will be less than the design requirement.

  13. Applications of geotextiles in sanitary landfills; Aplicacion de geotextiles en vertederos

    Cuenca Lorenzo, J. L.


    This article describes the applications of geo textiles in landfills with protection and filter functions. The usual way of design in many projects is revised in this paper and the needed properties to require to the geotextiles are showed too. Finally, a quality control of these properties which should be run to be sure that a good specified project is being fulfilled. (Author) 3 refs.

  14. Relationship between process parameters and properties of multifunctional needlepunched geotextiles

    Rawal, A


    Full Text Available , and filtration. In this study, the effect of process parameters, namely, feed rate, stroke frequency, and depth of needle penetration has been investigated on various properties of needlepunched geotextiles. These process parameters are then empirically related...

  15. Can geotextiles modify the transfer of heavy metals transported by stormwater in infiltration basins?

    Lassabatère, L; Winiarski, T; Galvez-Cloutier, R


    Geotextiles are fibrous materials increasingly employed for the design of infiltration basins. However, their influence on the transfer of contaminants carried by stormwater has not been fully investigated. This study, based on column leaching experiments, aims at showing the effect of geotextiles on the transfer of three heavy metals (Zn, Pb and Cd) in a reactive soil (simulating an infiltration basin at laboratory scale). This effect depends on several factors, such as type of geotextile, hydric conditions (geotextile water content), hydraulic conditions (flow-rates) and the number of geotextiles installed. In all cases, geotextiles influence heavy metal retention by modifying flow and thus regulating contact between these metals and the reactive soil.

  16. Subgrade strengthening of roads and railroads as planar geotextile reinforcement

    Gradkowski Krzysztof


    Full Text Available The proper quality of construction of roads and railroads can be achieved by strengthening the of the foundation bed. Measurements and tests the number and order of the layers of geotextile layer of ground indicate the effectiveness of technical solutions involving the reinforcement laid horizontally. The offer technical use of the geotextile reinforcement in the ground layer substrates of roads indicates the possible effectiveness of the strengthening of the subsoil of roads and is also included in this article.

  17. Subgrade strengthening of roads and railroads as planar geotextile reinforcement

    Gradkowski Krzysztof


    The proper quality of construction of roads and railroads can be achieved by strengthening the of the foundation bed. Measurements and tests the number and order of the layers of geotextile layer of ground indicate the effectiveness of technical solutions involving the reinforcement laid horizontally. The offer technical use of the geotextile reinforcement in the ground layer substrates of roads indicates the possible effectiveness of the strengthening of the subsoil of roads and is also incl...

  18. Engineering and Design: Use of Geotextiles Under Riprap


    of both surface and groundwater and close inspection during construction proved to be essential. 5. General . a. The majority of the riprap had a top...Table 1 (see Inclosure 1). Only limited use was made of nonwoven geotextile. b. Over 2,500,000 square yards of geotextile was placed in the Divide Cut...inspection during construction and insistence upon a very low drop height of the stone reduced, but did not totally eliminate damage. * Geotextlles as used

  19. Removal of suspended solids from municipal wastewater using geotextile columns

    Akram, M.H. [Texas Tech Univ., Lubbock, Texas (United States); Kotha, K.K. [Hillis-Carnes Inc., Manassas, VA (United States)


    A laboratory investigation was conducted to investigate the filtration behavior of geotextiles to remove suspended solids from municipal wastewater. Four nonwoven geotextiles were used in this preliminary investigation. The study also involved evaluating the suspended solids removal efficiency and regeneration potential of geotextiles for using as filter media. Wastewater samples were collected from the local wastewater treatment plant. Influent and effluent suspended solids concentration, chemical oxygen demand, and effluent flow rates were monitored during the tests. During filtration tests, suspended solids were retained on the upstream face and within the geotextile as wastewater passed through it. Due to the formation of a thin layer of suspended solids or filter cake on the upstream face of the geotextile, the effluent flow rate and suspended solids concentration decreased exponentially with time. When the effluent flow rate reduced below 90%, the filter media was backwashed to restore its filtering efficiency, for reuse. Based on the results of this study, it was concluded that using geotextile columns, it was possible to remove 50 to 70% of suspended solids and decrease in chemical oxygen demand from 70 to 90% from the influent. This technique may be suitable for treating wastewater streams with low inflow and suspended solids concentrations, preferably in the range of 100 to 200 mg/L. The technique may be further evaluated for determining its suitability for treatment of wastewater generated from less populated areas and as a polishing step after secondary treatment. (author)

  20. Further developments in self-fertilising geotextiles for use in pervious pavements.

    Newman, A P; Nnadi, E O; Duckers, L J; Cobley, A J


    Geotextiles incorporating inorganic nutrients (particularly phosphorous) to enhance the growth of oil degrading microoganisms when geotextiles are used in pervious pavement applications have been shown to be effective in the past. However the cost and manufacturing difficulties have been a barrier to their use. A polypropylene random mat geotextile incorporating an alternative polymer additive as a source of phosphorus has been investigated as a potential self-fertilising geotextile. Experiments are reported which investigate nutrient leach rates, biofilm formation and biodegradation activity.

  1. Theoretical Permeability of Two-layered Nonwoven Geotextiles

    LIU Li-fang; CHU Cai-yuan


    The two-layered nonwoven geotextile, which consists of a layer constructed with fine fibers for providing optimal filtration characteristics and another layer constructed with coarse fibers for providing the required mechanical properties, is desirable for drainage and filtration system.Based on Darcy's law and drag force theory, a mathematical model on vertical permeability coefficient of two-layered nonwoven geotextile is estabilished. Comparison with experimental results shows that the present model possesses 83.6% accuracy for needle-punched two-layered nonwoven geotextiles. And experimental results also show that with the increasing of needle density the vertical permeability coefficient of two-layered nonwoven geotextiless firstly decreases and then increases, reaching the smallest value at 470 p/cm2.

  2. Experimental Study on Pull-out Behavior of Different Geotextiles

    ZHOU Rong; DING Xin


    The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The interface frictional characters of two kinds of geotextiles (woven and needle-punched nonwoven) are investigated through pullout test.Nonwoven specimen has more wide variety of displacement along length than that of woven under the same pressure because of their different exteusibility. The greater the elongation and deformation of specimens, the more evident the variations of displacement along reinforcement from front to pullout end. The greater the normal pressure, the smaller the displacement of every position along length with the same pullout load. The study focuses on the effects of the tensile modulus and the difference of pullout response between woven and nonwoven geotextiles.

  3. Design Methods for Geotextile Tubes Application in Dike Construction

    YAN Yue; YAN Shu-wang; QIU Chang-lin; ZHENG Gang


    The technique of geotextile tubes used to construct dikes for land reclamation has been widely used. The tubes are usually filled with slurry of soil, such as sand, silt or clay. The tensile stress developed in the geotextile during filling the tube is the dominant factor for construction of a safe dike. The existing design methods are good for designing sausage shaped tubes and can not be directly applied for designing flat tubes, which are commonly used in dike construction. This paper presents a procedure that can determine the relationship among the tube size, the pumping pressure, the unit weight of the slurry, and the tensile stress developed in the geotextile during the tube filing. When the tubes are piling up to form the dike, the tubes in the bottom will sustain the load from the weight of the upper ones. A procedure is also developed to calculate the changes of the mechanical and geometrical behavior of the tubes under the load with a similar method. All these approaches have been programmed, which can help dike designers to select the suitable geotextile and determine the profile of the dike.

  4. Intelligent Tester for Geotextiles Products-Determination of Water Flow Capacity in their Plane

    FENG Yu-sheng; SONG Bai-ping


    Geotextiles and geotextile-related products Determination of water flowcapacity in their plane has just National standard. But has not a formal instrument at present. There are many kinds of geotextile and also lots of factors influential to the penetration coefficient thereof. The intelligent tester may be involved in testing penetration coefficient under different pressures/gradients resulted in fine repeatability controlled intelligently by microcomputer system.

  5. Utilization of Geotextile Tube for Sandy and Muddy Coastal Management: A Review

    Siew Cheng Lee; Roslan Hashim; Shervin Motamedi; Ki-Il Song


    Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However...

  6. Study on the Relation between Individual Layer and Multi-layered Nonwoven Geotextile Permeability

    刘丽芳; 储才元


    Water permeability is an important property of nonwoven geotextiles used in drainage field, and usually it is obtained by testing individual layer or multi-layered nonwoven geotextiles. However, the permeability coefficient tested by using different layers would be different for the same nonwoven geotextile. In this paper, the relation between them is studied based on Darcy's law. The study shows that vertical permeability coefficients are theoretically invariable no matter how many layers are tested; but experimental results show that vertical permeability coefficients decrease with the increase of nonwoven geotextile layers number.

  7. Experimental investigation on removal of suspended particles from water using flax fibre geotextiles.

    Abbar, Bouamama; Alem, Abdellah; Pantet, Anne; Marcotte, Stéphane; Ahfir, Nasre-Dine; Duriatti, Davy


    Natural geotextiles are increasingly used in geotechnical applications such as bank protection and short-term soil reinforcement. This study aimed to highlight the behaviour of natural flax fibre geotextiles towards the retention of suspended particles (SP) present in urban runoff and often polluted. Indeed, it is well known that a large fraction of the heavy metals are often associated with the SP. Long-term filtration tests were performed on four laboratory filter designs. The objective was to study the influence of a nonwoven flax fibre geotextiles on SP transfer through a sandy porous media under saturated conditions. The experiments consisted of injecting SP in a column filled with sand with and without flax fibre geotextiles at a constant flow rate. The results showed that nonwoven flax fibre geotextiles can increase flow homogeneity. Retention efficiency of SP at column scale as well as spatial deposition profile was modified by the presence of geotextile. The use of flax fibre geotextiles increases considerably the durability of the filtration system. Particle size analysis of the particles retained in the sand medium and in geotextiles shows that the coarser particles are mainly deposited at the entrance of the column, and in the geotextiles.

  8. Stress Distribution of Holed Geotextile Cross-section in Civil Engineering

    SHANG Xin-ping; CHU Cai-yuan


    Stress distribution of holed geotextile cross-section under uniaxial and double-axial tension is analyzed with the boundary element method (BEM). The calculation results indicate that stress distribution of holed geotextile crosssection is greatly related to the dimension of the specimen, the size of the hole, the shape of the hole and the tensile condition, and the stress concentration area of holed geotextile from the side of the hole to 3-4 times of the hole diameter should be strengthened in order to improve quality of the projects. These results could provide guidance for engineering application of geotextiles.

  9. Investigation on the Relationship between Specimen Width and Breaking Strength of Geotextile

    商欣萍; 储才元


    The tensile properties of geotextile are analyzed with the boundary element method, with special emphasis put on the influence of specimen width on geotextile breaking strength.The theoretical and experimental results showed that narrow specimen would underestimate the tensile strength of the geotextile. During testing procedure, the lateral contraction of the specimen is the main reason that causes the breaking strength to be on the lower side. The theoretical results also indicate that the breaking strength of the geotextile would arrive at a fixed value when the specimen width is increased to a certain extent.

  10. Laboratory Measurement of Pullout Resistance of Geotextiles Against Cohesive Soils


    with three geosynthetics (two geotextiles and a geogrid) and two normal loads. However, as geogrids were not being used in the reinforced levee...and the rate of shear deformation at interface of soil and rubber 49. Even though slightly different geosynthetics were used, the soils and molding...Testing of Geo- grids," Proceedings Geosynthetics 󈨛 Conference, New Orleans, La., Febru- ary 24-25, Industrial Fabrics Association International, St

  11. Shear strength behavior of geotextile/geomembrane interfaces

    Belén M. Bacas


    Full Text Available This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces, the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A large direct shear machine is used to carry out 90 geosynthetic interface tests. The test results show a strain softening behavior with a very small dilatancy (<0.5 mm and nonlinear failure envelopes at a normal stress range of 25–450 kPa. The influences of the micro-level structure of these geosynthetics on the macro-level interface shear behavior are discussed in detail. This study has generated several practical recommendations to help professionals to choose what materials are more adequate. From the three geotextiles tested, the thermally bonded monofilament exhibits the best interface shear strength under high normal stress. For low normal stress, however, needle-punched monofilaments are recommended. For the regular textured geomembranes tested, the space between the asperities is an important factor. The closer these asperities are, the better the result achieves. For the irregular textured geomembranes tested, the nonwoven geotextiles made of monofilaments produce the largest interface shear strength.

  12. Surface Heave Behaviour of Coir Geotextile Reinforced Sand Beds

    Lal, Dharmesh; Sankar, N.; Chandrakaran, S.


    Soil reinforcement by natural fibers is one of the cheapest and attractive ground improvement techniques. Coir is the most abundant natural fiber available in India and due to its high lignin content; it has a larger life span than other natural fibers. It is widely used in India for erosion control purposes, but its use as a reinforcement material is rather limited. This study focuses on the use of coir geotextile as a reinforcement material to reduce surface heave phenomena occurring in shallow foundations. This paper presents the results of laboratory model tests carried out on square footings supported on coir geotextile reinforced sand beds. The influence of various parameters such as depth of reinforcement, length, and number of layers of reinforcement was studied. It was observed that surface heave is considerably reduced with the provision of geotextile. Heave reduction up to 98.7% can be obtained by the proposed method. Heave reduction is quantified by a non-dimensional parameter called heave reduction factor.

  13. Shear strength behavior of geotextile/geomembrane interfaces

    Belén M. Bacas; Jorge Cañizal; Heinz Konietzky


    This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces, the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A large direct shear machine is used to carry out 90 geosynthetic interface tests. The test results show a strain softening behavior with a very small dilatancy (<0.5 mm) and nonlinear failure envelopes at a normal stress range of 25e450 kPa. The influences of the micro-level structure of these geosynthetics on the macro-level interface shear behavior are discussed in detail. This study has generated several practical recommendations to help professionals to choose what materials are more adequate. From the three geotextiles tested, the thermally bonded monofilament exhibits the best interface shear strength under high normal stress. For low normal stress, however, needle-punched monofilaments are recommended. For the regular textured geomembranes tested, the space between the asperities is an important factor. The closer these asperities are, the better the result achieves. For the irregular textured geomembranes tested, the nonwoven geotextiles made of monofilaments produce the largest interface shear strength.

  14. Geotextile composition, application and ecotoxicology-A review.

    Wiewel, Barbara Vé; Lamoree, Marja


    Geosynthetics is the umbrella term for thin, flexible material sheets applied in civil and environmental engineering, of which geotextiles form the largest group. Most geotextiles consist of a polymer from the polyolefin, polyester or polyamide family, and additives to improve their stability. The polymer may degrade into microplastic particles over time and under various conditions and can cause adverse effects, as species may ingest these particles or encounter adverse effects due to the interference of the particles with e.g. their photosynthesis system in the case of algae. Leaching of additives may occur from the intact material, as they are often not covalently bound to the polymer backbone, but is greatly enhanced when micro-sized plastic particles have been formed. A total of 42 polymer additives were identified, of which 26 had ecotoxicity information available in terms of a REACH persistence, toxicity and bioaccumulation (PBT) assessment. Of these, 15 were classified as (very) persistent and 2 as toxic. A survey to assess potential toxicity of the remaining 16 substances revealed that no ecotoxicity studies had been performed on 13 of these compounds. For 3 compounds, other toxicity data was found, as well as of several chemical groups known to be used as additives in geotextiles. The current knowledge is thus lacking in two domains: on the one hand, ecotoxicity data is scarce as many substances have not yet been the subject of ecotoxicological studies. On the other hand, in situ toxic effects might be missed by the current approach of single compound toxicity testing. Moreover, environmental occurrence data of the additives are extremely scarce. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Experimental study using coir geotextiles in watershed management

    Vishnudas, S.; Savenije, H. H. G.; van der Zaag, P.; Anil, K. R.; Balan, K.


    This paper presents the results of a field experiment conducted in Kerala, South India, to test the effectiveness of coir geotextiles for embankment protection. In the context of sustainable watershed management, coir is a cheap and locally available material that can be used to strengthen traditional earthen bunds or protect the banks of village ponds from erosion. Particularly in developing countries, where coir is abundantly available and textiles can be produced by small-scale industry, this is an attractive alternative for conventional methods.

  16. Experimental study using coir geotextiles in watershed management

    S. Vishnudas


    Full Text Available This paper presents the results of a field experiment conducted in Kerala, South India, to test the effectiveness of coir geotextiles for embankment protection. In the context of sustainable watershed management, coir is a cheap and locally available material that can be used to strengthen traditional earthen bunds or protect the banks of village ponds from erosion. Particularly in developing countries, where coir is abundantly available and textiles can be produced by small-scale industry, this is an attractive alternative for conventional methods.

  17. Performance of Chemically Treated Jute Geotextile in Unpaved Roads at Different in situ Conditions

    Midha, Vinay Kumar; Joshi, Shubham; Suresh Kumar, S.


    Biodegradable jute geotextiles are an effective reinforcing material for unpaved roads, but its serviceability is limited because of faster microbial degradation. Different methods are in use to improve the serviceability of jute geotextiles. In this paper, influence of chemical treatment (transesterification and bitumen coating), road design and rainfall intensity on the time dependent serviceability of jute geotextiles has been studied. Chemically treated jute geotextiles, were laid in unpaved road designs with and without sand layer, for 30, 60 and 90 days' duration, and subjected to simulated rainfall intensities of 50 and 100 mm/h. With increase in time of usage, tensile strength and puncture resistance decrease due to microbial attack, and pore size decreases due to clogging of soil in jute geotextiles. Chemical treatment was observed to have greater influence on the serviceability, followed by the presence of sand layer in road design and the rainfall intensity. Further, overall performance of bitumen coated jute geotextiles was observed to be better than transesterified jute geotextile, due to its hydrophobic nature.

  18. Utilization of geotextile tube for sandy and muddy coastal management: a review.

    Lee, Siew Cheng; Hashim, Roslan; Motamedi, Shervin; Song, Ki-Il


    Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However, for the muddy coasts, mangrove rehabilitation and conservation were additional concerns in coastal management schemes. The mangrove forests are natural barriers which can be found on the muddy coasts of many tropical countries. In this paper, the viability of geotextile tubes in sandy and muddy beaches was analysed. The advantages and disadvantages of the utilization of geotextile tubes in coastal management were discussed based on the experiences from the tropical countries such as Mexico, Malaysia, and Thailand. From the case studies, impressive improvements in coastal restoration after installation of geotextile tubes were shown. Based on the discussion, several recommendations to improve the application of geotextile tubes were suggested in this paper.

  19. Utilization of Geotextile Tube for Sandy and Muddy Coastal Management: A Review

    Lee, Siew Cheng; Hashim, Roslan; Motamedi, Shervin; Song, Ki-Il


    Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However, for the muddy coasts, mangrove rehabilitation and conservation were additional concerns in coastal management schemes. The mangrove forests are natural barriers which can be found on the muddy coasts of many tropical countries. In this paper, the viability of geotextile tubes in sandy and muddy beaches was analysed. The advantages and disadvantages of the utilization of geotextile tubes in coastal management were discussed based on the experiences from the tropical countries such as Mexico, Malaysia, and Thailand. From the case studies, impressive improvements in coastal restoration after installation of geotextile tubes were shown. Based on the discussion, several recommendations to improve the application of geotextile tubes were suggested in this paper. PMID:24955408

  20. Performance of Chemically Treated Jute Geotextile in Unpaved Roads at Different in situ Conditions

    Midha, Vinay Kumar; Joshi, Shubham; Suresh Kumar, S.


    Biodegradable jute geotextiles are an effective reinforcing material for unpaved roads, but its serviceability is limited because of faster microbial degradation. Different methods are in use to improve the serviceability of jute geotextiles. In this paper, influence of chemical treatment (transesterification and bitumen coating), road design and rainfall intensity on the time dependent serviceability of jute geotextiles has been studied. Chemically treated jute geotextiles, were laid in unpaved road designs with and without sand layer, for 30, 60 and 90 days' duration, and subjected to simulated rainfall intensities of 50 and 100 mm/h. With increase in time of usage, tensile strength and puncture resistance decrease due to microbial attack, and pore size decreases due to clogging of soil in jute geotextiles. Chemical treatment was observed to have greater influence on the serviceability, followed by the presence of sand layer in road design and the rainfall intensity. Further, overall performance of bitumen coated jute geotextiles was observed to be better than transesterified jute geotextile, due to its hydrophobic nature.

  1. Utilization of Geotextile Tube for Sandy and Muddy Coastal Management: A Review

    Siew Cheng Lee


    Full Text Available Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However, for the muddy coasts, mangrove rehabilitation and conservation were additional concerns in coastal management schemes. The mangrove forests are natural barriers which can be found on the muddy coasts of many tropical countries. In this paper, the viability of geotextile tubes in sandy and muddy beaches was analysed. The advantages and disadvantages of the utilization of geotextile tubes in coastal management were discussed based on the experiences from the tropical countries such as Mexico, Malaysia, and Thailand. From the case studies, impressive improvements in coastal restoration after installation of geotextile tubes were shown. Based on the discussion, several recommendations to improve the application of geotextile tubes were suggested in this paper.

  2. Laboratory Studies on Granular Filters and Their Relationship to Geotextiles for Stormwater Pollutant Reduction

    Parneet Paul


    Full Text Available Applications of geotextiles within tertiary stormwater treatment systems and for stormwater infiltration can provide a substrate for biofilm formation, enabling biological treatment of contaminants. Geotextiles can serve as an efficient part of stormwater filtration within the urban water environment. The project assessed the applications of three experimental granular filters as a sustainable urban drainage system (SUDS for the decomposition of organic pollutant loading present in stormwater. The three filter rigs were packed with alternating layers of filter media consisting of gravel, pea gravel, sand and either a single, double or no layer of geotextile membrane. A nonwoven geotextile was layered within the filter media. The hydraulic loading capacity for the three filters matched that commonly used with conventional sand filters systems. Water quality parameters were quantified by measuring suspended solids, chemical oxygen demand, dissolved oxygen, pH, nitrate-nitrogen, and phosphate concentrations. It was found that Filter Rig No. 3 (upper and lower geotextile membrane and Filter Rig No. 2 (single geotextile membrane had a significant statistical difference in treatment performance from Filter Rig No. 1 (no geotextile membrane.

  3. Numerical Evaluation of Size Effect on the Stress-Strain Behaviour of Geotextile-Reinforced Sand

    Hosseinpour, I.; Mirmoradi, S.H.; Barari, Amin;


    This paper studies the effect of sample size on the stress-strain behavior and strength characteristics of geotextile reinforced sand using the finite element numerical analysis. The effect of sample size was investigated by studying the effects of varying the number of geotextile layers...... axial strain at failure in comparison with large-sized samples. The size effect on the behavior of samples became further apparent when the number of geotextile layers was increased or the confining pressure was decreased. In addition, the results indicated that the magnitude of the size effect...

  4. Evaluation of geotextile filtration applying coagulant and flocculant amendments for aquaculture biosolids dewatering and phosphorus removal

    Wastes contained in the microscreen backwash discharged from intensive recirculating aquaculture systems were removed and dewatered in simple geotextile bag filters. Three chemical coagulation aids, (aluminum sulfate (alum), ferric chloride, and calcium hydroxide (hydrated lime)), were tested in com...

  5. Laboratory studies on granular filters and their relationship to geotextiles for stormwater pollutant reduction

    Parneet, Paul; Tota-Maharaj, Kiran


    Applications of geotextiles within tertiary stormwater treatment systems and for stormwater infiltration can provide a substrate for biofilm formation, enabling biological treatment of contaminants. Geotextiles can serve as an efficient part of stormwater filtration within the urban water environment. The project assessed the applications of three experimental granular filters as a sustainable urban drainage system (SUDS) for the decomposition of organic pollutant loading present in stormwate...

  6. Effectiveness of coir geotextiles in soil moisture conservation

    Beena K S


    Full Text Available Among the diversified use of coir geotextiles, its use as a protective covering to improve crop productivity and to reduce weed problem assumes to be much significant. An experiment has been conducted at Kumbazha, in Pathanamthitta district, Kerala, India to evaluate the different types of coir geotextiles and polythene as soilmulch. The treatments include different mulching materials like natural needled felt, black needled felt, rubberized coir, black polythene and transparent polythene along with a control plot (no mulch. The experiment was laid out in Completely Randomized Design with six replications. The test crops used were bhindi (var. Salkeerthi and pineapple (var. Mauritius. The study reveals that with bhindi crop growth parameters like plant height, leaf number and lateral spread were increased by mulching with rubberized coir and transparent polythene. These two mulches caused early flowering and increased fruit yield. Coir materials as mulch recorded a yield increase ranging from 67 to 196%. Observations also reveal that weeds were not grown in plots mulched with black polythene, transparent polythene and rubberized coir. Rubberized coir as mulch enhancedthe fruit yield in the case of pineapple, which is followed by natural needled felt and transparent polythene. Black polythene resisted weed growth up to 7MAP, whereas rubberized coir and transparent polythene suppressed weeds up to 8MAP. Though the weeds were grown in other treatments the weeds count was significantly lower than that of control plot. Mulching with transparent polythene enhanced the soil temperature whereas rubberized coir lowered soil temperature. More over all mulched treatments had a favourable influence in increasing soil moisture. Observing the biodegradability and eco-friendly nature of coir it could be inferred that rubberized coir can serve as good mulch for bhindi and pineapple with minimum weed problem.

  7. Use of palm-mat geotextiles for rainsplash erosion control

    Bhattacharyya, R.; Fullen, M. A.; Davies, K.; Booth, C. A.


    Soil detachment by raindrop action (rainsplash erosion) is a very important subprocess of erosion by water. It is a particular problem in the UK as most soils are sandy or loamy sand in texture and lands have gentle to medium slope. However, few studies report potential rainsplash erosion control options under field conditions. Hence, the utilization of palm-mat geotextiles as a rainsplash erosion control technique was investigated at Hilton, east Shropshire, U.K. (52°33'5.7″ N, 2°19'18.3″ W). Geotextile-mats constructed from Borassus aethiopum (Borassus palm of West Africa) and Mauritia flexuosa (Buriti palm of South America) leaves are termed Borassus mats and Buriti mats, respectively. Two-year field experiments were conducted at Hilton to study the effects of emplacing Borassus and Buriti mats on rainsplash erosion of a loamy sand soil. Two sets (12 plots each) of experiments were established to study the effects of these mats on splash height and splash erosion. Splash height needs to be known to assess the transport mechanism of major soil fraction and its constituents on sloping land by rainsplash. In both sets, six randomly-selected plots were covered with mats, and the rest were bare. Results (during 22/01/2007‒23/01/2009; total precipitation = 1731.5 mm) show that Borassus mat-covered plots had ˜ 89% ( P 0.05) effect in rainsplash erosion control during that period, although plots with Buriti mats significantly ( P 0.05) improve selected soil properties (i.e., soil organic matter, particle size distribution, aggregate stability and total soil carbon) as soil organic matter (SOM) input from mat-decomposition was much less than total SOM content. However, the changes in fine and medium sand contents (after 2 years) in the Borassus covered plots were significantly ( P < 0.05; n = 6) related to the total rainsplash erosion during 2007‒2009. Emplacement of Borassus and Buriti mats on bare soils did not decrease SOM contents after 2 years, indicating

  8. Effect of geotextile and cement on the performance of sabkha subgrade

    Aiban, S.A.; Al-Ahmadi, H.M.; Siddique, Z.U.; Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Asi, I.M. [Department of Civil Engineering, Hashemite University, Zarqa 13115 (Jordan)


    Many construction and post-construction problems have been reported in the literature when sabkha soils have been used without an understanding of their abnormal behavior, especially their inferior loading capability in their natural conditions. The strength of these soils can be further significantly decreased if the sabkha is soaked. The main objective of this study was to upgrade the load-carrying capacity of pavements constructed on sabkha soils using geotextiles, and to assess the effect of geotextile grade, base thickness, loading type (static and dynamic) and moisture condition (as-molded and soaked) on the performance of soil-fabric-aggregate (SFA) systems. In addition, the sabkha soil was treated with different dosages (5%, 7%, and 10%) of Portland cement and the performance of cement-stabilized sabkha was compared to that of the SFA system under different testing conditions. The ANOVA results indicated that the use of geotextile has a beneficial effect on sabkha soils, especially under wet conditions. Although the improvement in the load-carrying capacity of sabkha samples with high dosages of cement showed better results than the inclusion of geotextile, an economic analysis showed that the use of geotextiles would be superior. Moreover, mechanistic analysis was used to develop a prediction model for the percentage increase in the modulus of resilience. (author)

  9. Effectiveness of biological geotextiles in reducing runoff and soil loss under different environmental conditions using laboratory and field plot data

    Smets, T.


    Preliminary investigations suggest biological geotextiles could be an effective and inexpensive soil conservation method, with enormous global potential. Biological geotextiles are a possible temporary alternative for vegetation cover and can offer immediate soil protection. However, limited data are available on the erosion-reducing effects of biological geotextiles. Therefore, the objective of this study is to evaluate the effectiveness of selected types of biological geotextile in reducing runoff and soil loss under controlled laboratory conditions and under field conditions reflecting different environments (i.e. continental, temperate and tropical). In laboratory experiments, interrill runoff, interrill erosion and concentrated flow erosion were simulated using various rainfall intensities, flow shear stresses and slope gradients. Field plot data on the effects of biological geotextiles on sheet and rill erosion were collected in several countries under natural rainfall (U.K., Hungary, Lithuania, South Africa, Brazil, China and Thailand). The laboratory experiments indicate that all tested biological geotextiles were effective in reducing interrill runoff (on average 59% of the value for bare soil) and interrill erosion rates (on average 16% of the value for bare soil). Since simulated concentrated flow discharge sometimes flowed below the geotextiles, the effectiveness in reducing concentrated flow erosion was significantly less (on average 59% of the value for bare soil). On field plots, where both interrill and rill erosion occur, all tested geotextiles reduced runoff depth by a mean of 54% of the control value for bare soil and in some cases, runoff depth increased compared to bare soil surfaces, which can be attributed to the impermeable and hydrophobic characteristics of some biological geotextiles. In the field, soil loss rates due to interrill and rill erosion were reduced by a mean of 21% of the value of bare soil by biological geotextiles. This study

  10. The protective and attractive covering of a vegetated embankment using coir geotextiles

    S. Vishnudas


    Full Text Available This paper presents the results of a field experiment conducted in Kerala, South India, to test the effectiveness of coir geotextiles for embankment protection. The results reveal that treatment with geotextile in combination with grass is an effective eco-hydrological measure to protect steep slopes from erosion. In the context of sustainable watershed management, coir is a cheap and locally available material that can be used to strengthen traditional earthen bunds or protect the banks of village ponds from erosion. Particularly in developing countries, where coir is abundantly available and textiles can be produced by small-scale industry, this is an attractive alternative for conventional methods. This paper analyses the performance of coir geotextile in different treatments with respect to soil moisture content, protection against erosion and biomass production.

  11. A new procedure for treatment of oily slurry using geotextile filters.

    Mendonça, M B; Cammarota, M C; Freire, D D C; Ehrlich, M


    A new procedure to mitigate the environmental impacts and reduce the cost of disposal of oil slurry is present in this paper. Waste from the petroleum industry has a high environmental impact. Systems for oil-water separation have been used to mitigate the contamination potential of these types of effluents. At the outlet of these systems, the oil is skimmed-off the surface, while the slurry is removed from the base. Due to the high concentration of contaminants, the disposal of this slurry is an environmentally hazardous practice. Usually this type of waste is disposed of in tanks or landfills after removal from the industrial plant. Basically, the proposed procedure utilizes drying beds with geotextile filters to both reduce the water content in the slurry and obtain a less contaminated effluent. Laboratory tests were carried out to simulate the drying system. Four types of filters were analyzed: two non-woven geotextiles, one woven geotextile, and a sand filter.

  12. Proposed Design Graphs of Geotextile Reinforcement on Soft Clay under Various Field Conditions

    Putu Tantri K. Sari


    Full Text Available This paper describes the behavior of reinforced embankments constructed on soft clay subgrade with varying compressible depths, embankment slopes and embankment heights. The stability of the embankment is evaluated using the Bishop method. The resistance moment and the numbers of geotextiles required are examined. It is shown that varying the subgrade and embankment can significantly affect the embankment stability and also the number of reinforcements. It requires a lot of time to design embankment reinforcements, especially when the length of the embankment is tens of kilometers. The main aim of this study is to develop graphs to assist in designing the number of geotextile reinforcements. This paper proposes design graphs to support engineers and designers to determine the required geotextile reinforcements for embankments.

  13. Improvement of Marine Clay Performance Using Geo-Textile Encased Stone Column

    S. Siva Gowri Prasad


    Full Text Available The use of stone columns is a popular ground reinforcing technique for flexible structures like raft foundations, oil storage tanks, embankments etc. The stone column technique is a cost effective method of improving the strength parameters like bearing capacity and reduce the settlements. When stone columns in soft soil are loaded, it undergoes excessive bulging due to low lateral confinement. To avoid this excessive bulging, stone column is encased with geotextile. In the present study tests were performed with and without encasement of geotextile. Stone column is encased with geotextile with different lengths of encasement like L/4, L/2, 3L/4 & L. The tests indicate that the bearing capacity increases with increase of encasement length.

  14. The protective and attractive covering of a vegetated embankment using coir geotextiles

    Vishnudas, S.; Savenije, H. H. G.; van der Zaag, P.; Anil, K. R.; Balan, K.


    This paper presents the results of a field experiment conducted in Kerala, South India, to test the effectiveness of coir geotextiles for embankment protection. The results reveal that treatment with geotextile in combination with grass is an effective eco-hydrological measure to protect steep slopes from erosion. In the context of sustainable watershed management, coir is a cheap and locally available material that can be used to strengthen traditional earthen bunds or protect the banks of village ponds from erosion. Particularly in developing countries, where coir is abundantly available and textiles can be produced by small-scale industry, this is an attractive alternative for conventional methods. This paper analyses the performance of coir geotextile in different treatments with respect to soil moisture content, protection against erosion and biomass production.

  15. Conservation strategies on citrus plantation in eastern Spain. Catch crops, geotextiles and mulches

    Cerdà, Artemi; Dominguez, Alfons; Giménez Morera, Antonio


    Tillage (6 %), and herbicides (89 %) are the most widespread soil management methods in eastern Spain citrus orchards. The bare soils, the high intensity thunderstorms and the steep slopes result in high erosion rates. Over the last 3 years an experimental station has been developed at Montesa municipality in order to determine the effect of different types of mulch, geotextiles and catch crops. Rainfall simulation experiments on 20 m2 plots shown that soil losses can be control by catch crops (85 %), chipped pruned branches (89 %), straw mulch (97 %) and geotextiles (99 %). Then, vegetation can contribute to control the soil and water losses on the highly erodible soil of Mediterranean orchards.

  16. The effect of using a geotextile in a monolithic (evapotranspiration) alternative landfill cover on the resulting water balance.

    Sun, Jianlei; Yuen, Samuel T S; Fourie, Andy B


    This paper examines the potential effects of a geotextile layer used in a lysimeter pan experiment conducted in a monolithic (evapotranspiration) soil cover trial on its resulting water balance performance. The geotextile was added to the base of the lysimeter to serve as a plant root barrier in order to delineate the root zone depth. Both laboratory data and numerical modelling results indicated that the geotextile creates a capillary barrier under certain conditions and retains more water in the soil above the soil/geotextile interface than occurs without a geotextile. The numerical modelling results also suggested that the water balance of the soil cover could be affected by an increase in plant transpiration taking up this extra water retained above the soil/geotextile interface. This finding has a practical implication on the full-scale monolithic cover design, as the absence of the geotextile in the full-scale cover may affect the associated water balance and hence cover performance. Proper consideration is therefore required to assess the final monolithic cover water balance performance if its design is based on the lysimeter results.

  17. Pengaruh Ketebalan Media Geotextile dan Arah Aliran Slow Sand Filter Rangkaian Seri untuk Menyisihkan P Total dan N Total

    Ayuningtyas Ayuningtyas Ayuningtyas


    Full Text Available Pada penelitian ini dilakukan pengujian terhadap parameter-parameter yang berkaitan dengan standar kualitas air minum berdasarkan Peraturan Menteri Kesehatan Republik Indonesia No.492/MENKES/PER/IV/2010 pada air baku Kali Surabaya yang terlebih dahulu diolah pada unit pretreatment di IPAM Ngagel 1 Surabaya dan air yang akan diolah berasal dari outlet prasedimentasi. Air outlet prasedimentasi diolah terlebih dahulu menggunakan 4 unit roughing filter yang disusun secara seri kemudian diolah lebih lanjut ke unit slow sand filter dengan rangkaian seri. Digunakan dua variabel yaitu variasi arah aliran dan variasi ketebalan media geotextile. Media geotextile yang digunakan berjenis geotextile non woven. Ketebalan media geotextile yang digunakan sebesar 4 cm dan 6 cm sedangkan variasi arah aliran yang digunakan yaitu downflow-upflow dan downflow-downflow. Digunakan unit pengolahan slow sand filter dengan rangkaian seri sebanyak 2 reaktor. Pada penelitian ini akan dilakukan penambahan media geotextile di unit slow sand filter dan nantinya diharapkan supaya kandungan N total dan P total dapat diturunkan. Flow rate yang digunakan pada unit slow sand filter sebesara 0,3 m3/m2 jam. Tujuan dari penelitian ini yaitu untuk mengetahui ketebalan media geotextile dan arah aliran yang optimum pada unit slow sand filter dan menganalisis pengaruh penambahan media geotextile terhadap kualitas air hasil olahan unit slow sand filter untuk menyisihkan N total dan P total.

  18. Geotextiles-laying system & its Strength Analysis for Geotextiles-laying Vessels%铺排船上的铺排系统与强度分析

    李亮; 朱娜娜


    This article introduces the geotextiles-laying system, analyzes its state of stress as well as applies the finite element software to the strength analysis and checking of the elements for Geotextiles-laying system, which serves as reference for its design and improvement.%文章首先介绍了铺排船的铺排系统,分析了其受力情况,并通过有限元软件对组成铺排系统的各个元素进行了强度分析与校核,为铺排系统的设计与完善提供了参考。

  19. The development of geotextiles incorporating slow-release phosphate beads for the maintenance of oil degrading bacteria in permeable pavements.

    Spicer, G E; Lynch, D E; Coupe, S J


    The development of a self-fertilising geotextile mat designed to provide a sustained slow-release of required inorganic nutrients for the growth of oil degrading microorganisms in porous pavement systems (PPS) is reported. The system comprises a geotextile spun from polymer fibres containing spherical phosphated polymer beads that release phosphate upon contact with water at a desirable level for microbial growth. Initial results using model PPS have shown that the self-fertilising geotextile system works extremely effectively as increased microbial activity has been observed throughout the experiment, illustrating that the oil-degrading bacteria can effectively utilise this polymer composite as a suitable nutrient source.

  20. Influence of Processing Parameters on Properties of Needle punched Composite Geotextiles

    李婕; 储才元; 杨金魁; 张键


    The influence of the processing parameters on the properties of needle-punched composite geotextiles,compounded by polypropylene filament woven-fabrics and nonwoven fabrics is studied by using orthogonal design method. The relationship between tensile strength and peeling strength is discussed. The experimental results are offered as reference.

  1. Effect of Geotextile Reinforcement on Shear Strength of Sandy Soil: Laboratory Study

    Denine, Sidali; Della, Noureddine; Dlawar, Muhammed Rawaz; Sadok, Feia; Canou, Jean; Dupla, Jean-Claude


    This paper presents results of a series of undrained monotonic compression tests on loose sand reinforced with geotextile mainly to study the effect of confining stress on the mechanical behaviour of geotextile reinforced sand. The triaxial tests were performed on reconstituted specimens of dry natural sand prepared at loose relative density (Dr = 30%) with and without geotextile layers and consolidated to three levels of confining pressures 50, 100 and 200 kPa, where different numbers and different arrangements of reinforcement layers were placed at different heights of the specimens (0, 1 and 2 layers). The behaviour of test specimens was presented and discussed. Test results showed that geotextile inclusion improves the mechanical behaviour of sand, a significant increase in the shear strength and cohesion value is obtained by adding up layers of reinforcement. Also, the results indicate that the strength ratio is more pronounced for samples which were subjected to low value of confining pressure. The obtained results reveal that high value of confining pressure can restrict the sand shear dilatancy and the more effect of reinforcement efficiently.

  2. Geotextile filtration performance for lagoon sludges and liquid animal manures dewatering

    Maintenance and control of liquid levels in anaerobic lagoons and storage ponds require liquid-solid separation as a pretreatment and periodic removal of accumulated sludges. Until local options become available, sludges can be contained, dewatered, and stored using geotextile filtration. We used a ...

  3. The relative performance of geotextile and granular filters for containing PCBs

    Kalinovich, I.; Rutter, A.; Rowe, R.K.; Poland, J.S. [Queen' s Univ., Kingston, ON (Canada)


    This study examined the performance of geotextile and granular filters used with permanent barrier systems installed at a remediated polychlorinated biphenyl (PCB)-contaminated site on Resolution Island. The barrier system was installed to ensure that remaining soils at the site were not mobilized during periods of run-off. Three barriers were installed at the site, along with sediment traps and ponding areas to accommodate sediment loading. The filter box of the system consisted of 4 pairs of slots in which absorbent materials were placed. PCB contaminated soil was excavated from the site and flushed through a column at a constant flow rate and then filtered. Air was then blown through the column to dry the material inside. The column was then taken apart and samples were then analyzed using soxhlet extraction, gas chromatography, and an electron capture detector. Three geotextiles were examined in addition to absorbent booms and granulated activated carbon (GAC). Batch tests were conducted to evaluate adsorption of PCBs between 2 different types of GAC. Results of the study showed that geotextiles can minimize the escape of PCBs. However, GAC media were more durable and permeable. It was concluded that nonwoven geotextiles can be used to remove PCB-contaminated fines in combination with a granular, permeable reactive barrier system. 21 refs., 4 tabs., 1 fig.

  4. Water Quality Improvement Performance of Geotextiles Within Permeable Pavement Systems: A Critical Review

    Miklas Scholz


    Full Text Available Sustainable drainage systems (SuDS; or best management practices are increasingly being used as ecological engineering techniques to prevent the contamination of receiving watercourses and groundwater. Permeable paving is a SuDS technique, which is commonplace in car parks, driveways and minor roads where one of their functions is to improve the quality of urban runoff. However, little is known about the water quality benefits of incorporating an upper geotextile within the paving structure. The review focuses on five different categories of pollutants: organic matter, nutrients, heavy metals, motor oils, suspended solids originating from street dust, and chloride. The paper critically assesses results from previous international tests and draws conclusions on the scientific rigour and significance of the data. Findings indicate that only very few studies have been undertaken to address the role of geotextiles directly. All indications are that the presence of a geotextile leads only to minor water quality improvements. For example, suspended solids are being held back by the geotextile and these solids sometimes contain organic matter, nutrients and heavy metals. However, most studies were inconclusive and data were often unsuitable for further statistical analysis. Further long-term research on industry-relevant, and statistically and scientifically sound, experimental set-ups is recommended.

  5. Laboratory Performance Testing of Two Types of Geotextiles used in Danube Hydrotechnical Works

    Dumitru, F. D.; Moncea, M. A.; Panait, A. M.; Olteanu, M.; Laslo, L.


    The products included in the geosynthetic category (geotextiles, geogrids, geonets, geomembranes, geosynthetic clay liners, geofoam, geocells (cellular confinement) and geocomposites) have multiple civil engineering uses, being effectively used as drains and filters in civil and environmental works. The paper aims to test the performance of the geotextiles used for the ecological restoration of riverbank defences on the Danube River, between Calarasi and Braila. For this purpose, the analysed geosynthetics were subjected to hydrolysis and oxidation degradation in laboratory conditions. To evaluate the effect of the two degradation mechanisms, the specimens were subjected to tensile tests at room temperature. The three analysed parameters were tensile strength, elongation and failure mode. The results showed that the tensile strength values for the samples subjected to oxidation and hydrolysis are lower than the ones corresponding to the reference samples, while the elongation values determined after mechanical testing showed that hydrolysis influences the fibre flexibility. The failure mode of the analysed geotextiles highlighted the tendency of the samples to fail either in the calibrated area or at the grip, indicating that in use the geotextile will break in the strained region.

  6. Improvement of Life Expectancy of Jute Based Needlepunched Geotextiles Through Bitumen Treatment

    Ghosh, S. K.; Ray Gupta, K.; Bhattacharyya, R.; Sahu, R. B.; Mandol, S.


    Geotextiles have witnessed unrivalled growth worldwide in recent years in the field of different civil engineering constructions. The world of Geotextiles includes mainly non-biodegradable synthetic materials which are not environmentally compatible. With the increasing human awareness on environmental pollution aspects, biodegradable Jute Geotextile is increasingly gaining ground over its synthetic non-biodegradable counterpart. Though Jute is advantageous for its complete biodegradability in one hand but on the other hand it is disadvantageous for its poor microbial resistance and quicker biodegradation particularly under moist soil conditions, when applied as Geotextiles under soil. Therefore, it is a great challenge to the present researchers to make jute more microbial resistant (rot resistant) keeping its biodegradability intact during its performance period. Thorough investigation and study regarding the improvement of the durability of natural Jute Geotextile reveals the fact that though several attempts including chemical treatments have been made to enhance the life expectancy of jute fabrics yet these methods were neither found to be suitable nor techno-economically viable. Therefore, in order to accomplish the objective and based on the researchers' report of satisfactory thermal compatibility between hot bitumen and jute nonwoven fabrics, in the present study Bitumen emulsion with essential additives has been applied following a special technique, apart from the conventional method, on the Grey Jute Nonwoven Fabrics in different add on percentages to make a comparative assessment of the performance of both Grey Jute Fabrics and Bituminized Jute Nonwoven Fabrics by Soil Burial Test as per the BIS standard test method. The test results revealed that the durability and performance of the Bituminized Nonwoven Jute Fabrics are much better than that of Grey Jute Nonwoven Fabrics.

  7. Rationale for the use of protective gaskets made of geotextiles and permeability evaluation of impervious coatings made of geomembranes

    Kosichenko Yuriy Mikhaylovich


    Full Text Available The purpose of this paper is to design rationale for the use of protective pads of geotextiles and geomembranes permeability of PD using these pads. In order to justify the use of protective pads made of geotextile for reducing the defectiveness geomembrane soil fractions, the existing formulas to determine the thickness of the film element of impervious devices were examined. The calculations according to the formulas show that HDPE geomembrane with a minimum thickness of 1,0 mm, the protective lining of the geotextile should be applied at the average diameter fractions of soil of more than 6,5 mm, and for geomembranes HDPE - at a diameter of soil fractions of over 15,5 mm. In order to estimate the permeability of the TFG geomembrane using additional protective linings of geotextile in the scientific article the basic design schemes of such coatings with one and two layers of protective linings of geotextiles were considered. The evaluation results of water permeability of impervious surfaces with geotextile and for comparison - without geotextiles are given in a table. As it is shown by the data presented for the design scheme with a single layer of geotextile geomembrane at the base (in the presence of small holes in the geomembrane the decrease the effectiveness of an anti-covering is more than 268,0 %, and for the settlement scheme covering with two layers of geotextile there will be a very large reduction in the efficiency, which almost completely reduces the effectiveness of the coating to the value of the geomembrane permeability of a soil layer without geomembrane with the filtration flow rate of 71,75 m /day, against water permeability of the geomembrane cover - 38,52 m /day. From the foregoing, it can be concluded that the application of a coating design of well filtering gaskets made of geotextile is justified in terms of protecting the geomembrane from mechanical damage, but greatly reduces the effectiveness of impervious cover in

  8. Sorption of heavy metals on a chitosan-grafted-polypropylene nonwoven geotextile

    Vandenbossche M.; Jimenez M.; Casetta M.; Bellayer S.; Bourbigot S.; Traisnel M.


    This work describes the development of an environmental friendly functionalized polypropylene nonwoven geotextile (PP) in order to trap heavy metals in sediments and sludges. Chitosan was chosen as the sorbent because of its ability to trap heavy metals, of its natural origin (from shells), and of its low cost. PP was first functionalized with acrylic acid using a cold plasma process, in order to bring some reactive carboxylic functions onto the surface. Chitosan was then covalently grafted o...

  9. Phenolic stabilisers extraction constants of polypropylene geotextiles determination in alkali medium

    Farcas, Fabienne; Fayolle, Bruno; Azzouz, Mériam; Richaud, Emmanuel


    The use of geotextiles made of polypropylene (PP) in civil engineering such as tunnel requieres adequates control over their durability, and this characteristic remains poorly known due to their inaccessibility. Considering concrete environment ageing conditions (alkali medium i.e. pH = 9 to 13), the aim of this study is to complete a non-empirical kinetic model for polypropylene ageing by the determination of the extraction parameters a frequently used phenolic process stabilisers: Irganox 1...

  10. Efficient technical solution for recycling textile materials by manufacturing nonwoven geotextiles

    Leon, A. L.; Potop, G. L.; Hristian, L.; Manea, L. R.


    This paper aims to support the concept "circular economy" that was developed recently. It presents an efficient method for creating a closed loop in the Romanian textile industry by recycling textile materials, such as polyacrylonitrile knitted old products (collected from population) and small polyester woven patches from pre-consumer waste (garments manufacturing companies). Because of their properties, nonwoven geotextiles have many advantages in railways reinforcement, slopes stabilization, erosion control, drainage, filtration, paving roads, crops coverings, etc. The nonwoven geotextiles were obtained from three fibrous blends based on recovered fibers (PES and PAN) and fibers at first usage (PP) in different ratios. All experimental variants were processed on the same manufacturing line with the same technological parameters. There were tested the main physical and mechanical parameters and it was applied single factor ANOVA method for thickness, bulk density, air permeability and static puncture strength. The conclusion is that adding PP fibers in the blends represents a very important factor for geotextiles characteristics but it possible to decrease the ratio from economical reasons and still maintain a high quality level of nonwovens.

  11. Performance and efficiency of geotextile-supported erosion control measures during simulated rainfall events

    Obriejetan, Michael; Rauch, Hans Peter; Florineth, Florin


    Erosion control systems consisting of technical and biological components are widely accepted and proven to work well if installed properly with regard to site-specific parameters. A wide range of implementation measures for this specific protection purpose is existent and new, in particular technical solutions are constantly introduced into the market. Nevertheless, especially vegetation aspects of erosion control measures are frequently disregarded and should be considered enhanced against the backdrop of the development and realization of adaptation strategies in an altering environment due to climate change associated effects. Technical auxiliaries such as geotextiles typically used for slope protection (nettings, blankets, turf reinforcement mats etc.) address specific features and due to structural and material diversity, differing effects on sediment yield, surface runoff and vegetational development seem evident. Nevertheless there is a knowledge gap concerning the mutual interaction processes between technical and biological components respectively specific comparable data on erosion-reducing effects of technical-biological erosion protection systems are insufficient. In this context, an experimental arrangement was set up to study the correlated influences of geotextiles and vegetation and determine its (combined) effects on surface runoff and soil loss during simulated heavy rainfall events. Sowing vessels serve as testing facilities which are filled with top soil under application of various organic and synthetic geotextiles and by using a reliable drought resistant seed mixture. Regular vegetational monitoring as well as two rainfall simulation runs with four repetitions of each variant were conducted. Therefore a portable rainfall simulator with standardized rainfall intensity of 240 mm h-1 and three minute rainfall duration was used to stress these systems on different stages of plant development at an inclination of 30 degrees. First results show

  12. Participatory research using coir geotextiles in watershed management A case study in south India

    Vishnudas, Subha; Savenije, Hubert H. G.; van der Zaag, Pieter; Anil, Kunnathu R.; Balan, Krishnan

    This paper deals with participatory research on the introduction and use of coir geotextiles for soil and water conservation in a small community pond in a watershed in south India. The results demonstrate that a participatory approach enables the community to visualize and evaluate the impact of innovative technologies. As a result, farmers readily adapt a technology when they have experienced the positive research outcome. This reduces the adoption time, and can bring significant increase in yield, or decrease in labour costs, helping to enhance productivity, sustainability and improvement of livelihood.

  13. Reinforcement of Soft Foundation with Geotextile and Observation for Sea Dike Project of Zhapu Port

    章香雅; 郑祖祯


    The design method of reinforcement of soft foundation with geotextile for the sea dike of the Zhapu Port is discussed in this paper. The prototype behaviours such as pore water pressure, settlement and so on were observed. The degree of consolidation is found out from observed pore water pressure and observed settlement respectively, then the strength increment of soil is calculated and compared with that obtained from vane shear tests. For the use of observed pore water pressure, the consolidation coefficient of soil is deduced approximately with a method named experimental exponential interpolation. The degree of consolidation of the ground is deduced theoretically from the dissipation of pore water pressure. Besides, the logarithmic curve and hyperbola are used to fit the observed time-settlement curve, and the degree of consolidation of soil is obtained according to the definition of the consolidation degree. After preliminary verification with observed prototype data, the method to reinforce the low dike with geotextile is considered to be simple and rational, and it can also reduce the construction cost.

  14. Influence of Strain Rate on Tensile Strength of Woven Geotextile in the Selected Range of Temperature

    Stępień Sylwia


    Full Text Available Investigation of geosynthetics behaviour has been carried out for many years. Before using geosynthetics in practice, the standard laboratory tests had been carried out to determine basic mechanical parameters. In order to examine the tensile strength of the sample which extends at a constant strain rate, one should measure the value of the tensile force and strain. Note that geosynthetics work under different conditions of stretching and temperatures, which significantly reduce the strength of these materials. The paper presents results of the tensile test of geotextile at different strain rates and temperatures from 20 °C to 100 °C. The aim of this study was to determine the effect of temperature and strain rate on tensile strength and strain of the woven geotextile. The article presents the method of investigation and the results. The data obtained allowed us to assess the parameters of material which should be considered in the design of the load-bearing structures that work at temperatures up to 100 °C.

  15. Improvement Of Sub-Grade Soil Properties Using Admixture Quarry Dust And Woven Geo-Textile

    G. Priya Vasudha


    Full Text Available Abstract The important factor for design and construction of pavement is the behavior of underlying sub-grade. Large deformations in the sub-grade will lead to a continuous deterioration of the paved surface. As the sub-grade soil is too weak to bear the load engineering solutions such as geo reinforcement using geo-synthetics are additives which are earlier used in sub-grade improvement and such experimental study is carried by pervious authors. This paper deals with the sub-grade improvement using geo-textile as a reinforcement sheet and quarry dust as admixtures. In order to increase the strength of the sub-grade the quarry dust is varied with different percentages i.e. 0 5 10 15 20 and 25. In this study Proctors compaction tests and CBR soaked and unsoaked tests are conducted on locally available soil with reinforced material and with admixture. For this study it is identified that the engineering properties of the soil is improved in all conditions. The soil with quarry dust at optimum value is 20 has CBR soaked value is obtained 6.83 and unsoaked value is obtained 7.02 is increased when compared with conventionally soil. The soil quarry dust at optimum value is at 20 and Geo-textile has CBR soaked value is 6.59 and unsoaked value is 8.95 is increased when compared with conventionally soil and soil with quarry dust.

  16. Membranas de impermeabilización y láminas geotextiles filtrantes

    Vié, George


    Full Text Available Georges Vié, Mining engineer This article deals with the various uses of non-traditional products: — the bituminous membrane, used for solving water-proofing problems in tanks and ponds having a relatively low water load, — the geotextile coating of non-woven sinthetic fibers, used because of their filtering capacity in the construction of the runway In the Marignane (Marseille airfield.

    Se exponen en este artículo varios usos de productos no tradicionales: — la membrana bituminosa, que sirve para resolver problemas de impermeabilización en depósitos y embalses, con carga de agua relativamente débil, y — la lámina geotextil, de fibras sintéticas no tejidas, utilizada por su poder filtrante en la construcción de la pista de despegue del aeródromo de Marignane (Marsella. Se explican también las principales características técnicas de estos materiales.

  17. Influence of Strain Rate on Tensile Strength of Woven Geotextile in the Selected Range of Temperature

    Stępień, Sylwia; Szymański, Alojzy


    Investigation of geosynthetics behaviour has been carried out for many years. Before using geosynthetics in practice, the standard laboratory tests had been carried out to determine basic mechanical parameters. In order to examine the tensile strength of the sample which extends at a constant strain rate, one should measure the value of the tensile force and strain. Note that geosynthetics work under different conditions of stretching and temperatures, which significantly reduce the strength of these materials. The paper presents results of the tensile test of geotextile at different strain rates and temperatures from 20 °C to 100 °C. The aim of this study was to determine the effect of temperature and strain rate on tensile strength and strain of the woven geotextile. The article presents the method of investigation and the results. The data obtained allowed us to assess the parameters of material which should be considered in the design of the load-bearing structures that work at temperatures up to 100 °C.

  18. Discussion on the nonwoven geotextile technology%浅谈非织造土工布技术

    信鹏月; 任元林; 苏倩


    The materials and production technique on manufacture nonwoven geotextile were introduced .The requirement on property of geotextile and performance and application of geotextile were present briefly . The change of development of geotextile was forecasted from traditional textile technology as main process to various technique used on manufacture product applied on several engineering .The product development would trend seriously , compositely and comprehensive .%  介绍了非织造土工布使用的原料、种类、生产工艺及其技术特点,简述了对土工布性能的要求,土工材料的功能及在工程中的应用。预测国内外土工材料的发展方向将由以传统纺织技术为主转向以适应各种工程需要为目的的开发生产为主,产品开发将趋向于系列化、复合化和综合化。

  19. Effects of geotextile landscape fabric on soil nutrient availability in an organic planting of ‘Marion’ trailing blackberry

    Geotextile landscape fabric, often referred to as weed mat, is becoming a popular option for weed control in many fruit crops, particularly for organic production. The present study was conducted in 2014 to evaluate the effects of landscape fabric relative to hand weeding on soil nutrient availabili...


    A technological base was sought for determining the chemical resistance and long-term durability of geotextiles, geonets, and pipe exposed to liquids representative of those in a waste containment facility. A desired end product was to develop and validate generalized test method...

  1. Effects of initial soil condition on the effectiveness of biological geotextiles in reducing interrill runoff and erosion

    Smets, T.; Poesen, J.


    The effectiveness of a surface cover material (e.g. geotextiles, rock fragments, mulches, vegetation) in reducing runoff and soil erosion rates is often only assessed by the fraction of the soil surface covered. However, there are indications that soil structure has important effects on the runoff and erosion-reducing effectiveness of the cover materials. This study investigates the impact of initial soil condition (i.e. fine tilth versus sealed soil surface) on the effectiveness of biological geotextiles in increasing infiltration rates and in reducing runoff and interrill erosion rates on a medium and steep slope gradient. Rainfall was simulated during 60 minutes with an intensity of 67 mm h-1 on an interrill erosion plot having two slope gradients (i.e. 15 and 45%) and filled with an erodible sandy loam. Five biological and three simulated geotextiles with different cover percentage were tested on two simulated initial soil conditions (i.e. fine tilth and sealed soil surface). Final infiltration rates on a sealed soil surface (7.5-18.5 mm h-1) are observed after ca. 10 minutes of rainfall compared to ca. 50 minutes of rainfall on an initial seedbed (16.4-56.7 mm h-1). On the two tested slope gradients, significantly (α = 0.05) smaller runoff coefficients (RC) are observed on an initial seedbed (8.2% geotextile cover. However, on an initial sealed soil surface no significant effect of simulated geotextile cover on RC is observed. On a 15% slope gradient, calculated b-values from the mulch factor equation equalled 0.054 for an initial fine tilth and 0.022 for a sealed soil surface, indicating a higher effectiveness of geotextiles in reducing interrill erosion on a fine tilth compared to a sealed soil surface. Therefore, this study demonstrates the importance of applying geotextiles on the soil surface before the surface tilth is sealed due to rainfall. The effect of soil structure on the effectiveness of a surface cover in reducing runoff and interrill erosion

  2. Influence of Immersion Conditions on The Tensile Strength of Recycled Kevlar®/Polyester/Low-Melting-Point Polyester Nonwoven Geotextiles through Applying Statistical Analyses

    Jing-Chzi Hsieh


    Full Text Available The recycled Kevlar®/polyester/low-melting-point polyester (recycled Kevlar®/PET/LPET nonwoven geotextiles are immersed in neutral, strong acid, and strong alkali solutions, respectively, at different temperatures for four months. Their tensile strength is then tested according to various immersion periods at various temperatures, in order to determine their durability to chemicals. For the purpose of analyzing the possible factors that influence mechanical properties of geotextiles under diverse environmental conditions, the experimental results and statistical analyses are incorporated in this study. Therefore, influences of the content of recycled Kevlar® fibers, implementation of thermal treatment, and immersion periods on the tensile strength of recycled Kevlar®/PET/LPET nonwoven geotextiles are examined, after which their influential levels are statistically determined by performing multiple regression analyses. According to the results, the tensile strength of nonwoven geotextiles can be enhanced by adding recycled Kevlar® fibers and thermal treatment.

  3. An Investigation into Reducing Time Dependent Creep of a Polyethylene Geotextile using Glass Fiber Yarns

    Xiong, Jun

    An investigation has been carried out to reduce the deformation behavior of polyethylene (PE) woven geotextile fabric by making PE fabric-glass yarn composite structure using stitching and laminating. The results showed that reinforcement significantly reduced the creep and IED as long as the tensile stress is lower than the total load bearing capacity of the glass yarns in the composite structure. However, the strength of PE-glass composite fabric was solely dependent on the strength of the glass yarns. The strength from PE yarns only contributes when all glass yarns are broken. Cast result of concrete columns using the glass yarn reinforced PE fabric by stitching method suggested that the glass yarn must face outside of the fabric formwork to avoid damage of both fabric surface and column surface.

  4. Laminated composite based on polyester geotextile fibers and polyurethane resin for coating wood structures

    Yuri Andrey Olivato Assagra


    Full Text Available New environmental laws have restricted the use of hardwood trees in overhead power lines structures, such as, poles and cross-arms, leading companies to seek alternative materials. Reforested wood coated with polymeric resin has been proposed as an environmental friendly solution, with improved electrical properties and protection against external agents, e.g. moisture, ultraviolet radiation and fungi. However, the single thin layer of resin, normally applied on such structures reveal to be inefficient, due to be easily damage during handling. In this paper, we present a composite coating, based on geotextile fibers and polyurethane resin that is suitable for wooden structures. Results obtained from two different tree species (from managed and reforested areas coated with the composite reveal that the additional layer not only provided a stronger adhesion between wood and ccoating layer but also a further improvement in the electrical properties and better protection against abrasion and moisture.

  5. Bedding on geotextile mattresses: how much is needed to improve cow comfort?

    Tucker, C B; Weary, D M


    The objective of our study was to evaluate how the amount of sawdust bedding on mattresses affects dairy cattle behavior and preferences. Eleven nonlactating, multiparous cows were housed individually in pens with access to 3 free stalls. Each stall was fitted with a geotextile mattress covered with either 0, 1, or 7.5 kg of kiln-dried sawdust. The experiment began with 7 d of acclimatization to all 3 stalls. Cows were then allowed access to only 1 of the 3 stalls at a time, each for 3 d (restriction phase). At the end of this restriction phase, cows were allowed free access to all 3 stalls for 3 d (free-choice phase). Time spent lying and the number of lying bouts increased significantly with the amount of bedding, from 12.3 +/- 0.53 h lying and 8.5 +/- 0.62 bouts per 24 h on bare mattresses to 13.8 +/- 0.53 h lying and 10.0 +/- 0.62 bouts per 24 h on mattresses with 7.5 kg of sawdust. In addition, the animals spent less time standing with only the front hooves in the stalls when more sawdust was present. When allowed free access to all 3 options, all 11 animals spent a majority of their time lying and standing in the 7.5-kg option. In conclusion, cows preferred mattresses bedded with 7.5 kg of sawdust, on which they spent more time lying down and less time standing with only the front hooves in stalls. These results indicate that more sawdust bedding improves cow comfort in stalls with geotextile mattresses.

  6. Hydrological Implications of Covering Wind-Blown Snow Accumulations with Geotextiles on Mount Aragats, Armenia

    Alexander Nestler


    Full Text Available Snow is an excellent water reservoir, naturally storing large quantities of water at time scales from a few days to several months. In summer-dry countries, like Armenia, runoff due to snow melt from mountain regions is highly important for a sustained water supply (irrigation, hydropower. Snow fields on Mount Aragats, Armenia’s highest peak, often persist until July, providing vital amounts of melt water. Artificially managing these wind-driven snow accumulations as a natural water reservoir might have considerable potential. In the context of the Swiss-Armenian joint venture, Freezwater, snow fields are covered with geotextiles in order to delay snow melt long enough to provide additional melt water in the dry season of the year. In this study, we analyze the hydrological effectiveness of the artificial management of the natural snow cover on Mount Aragats based on various field measurements acquired over a three-year period and numerical modeling. Over the winter season, partly more than five meter-thick snow deposits are formed supported by snow redistribution by strong wind. Repeated mappings of snow fields indicate that snow cover patterns remain highly consistent over time. Measurements of ablation below manually applied geotextiles show a considerable reduction of melt rates by more than 50%. Simulations with an energy-balance model and a distributed temperature-index model allow assessing the hydrological effect of artificial snow management for different initial snow depths and elevations and suggest that coverage is needed at a large scale in order to generate a significant impact on discharge.

  7. An economical view of soil conservation. The use of geotextil as a tool to teach on higher education

    Giménez Morera, Antonio; Cerdà, Artemi


    Soil and earth science did not take into account the important of economics to teach on higher education. Economics contribute with a positive view on applied soil and earth science. Only if the soil conservation strategies are feasible from an economic point of view they will be sustainable from an environmental point of view. This paper shows the strategies developed at the Soil Erosion and Degradation Experimental Station of El Teularet-Sierra de Enguera. By means of soil erosion plots and rainfall simulation experiments the students can understand the effect of geotextiles on soil erosion control and soil conservation. The task developed in the field, in the laboratory and in the lectures rooms, the students develop the calculations on how much cost the geotextiles and how much soil is protected. The results show that the students found the way to reach a sustainable soil conservation strategy based on soil science and on economics.


    Joanna Beata Grzybowska-Pietras


    Full Text Available In the engineering constructions there are used biodegradable geotextiles, that are performing primarily a function of surface anti-erosion protection. Their biodegradability supports the development of vegetation, and protects the surface of the slope from the moment of installation in the ground. In order to achieve this functionality there are used mainly biononwovens and woven fabrics made of natiral fibers. In the paper there are presented results of studies on the effect of the instalation of the biononwoven (Maliwatt type with grass seeds applied in real conditions at a specified time (from November to June, on the selected physical, mechanical and hydraulic properties , and the development of vegetation (grasses. The experiment adopted two versions of instalation of nonwovens. In the first case geotextile was mounted directly on the ground, in the second additionally have been covered with a layer of native soil.

  9. Coir geotextile for slope stabilization and cultivation - A case study in a highland region of Kerala, South India

    Vishnudas, Subha; Savenije, Hubert H. G.; Van der Zaag, Pieter; Anil, K. R.

    A sloping field is not only vulnerable to soil erosion it may also suffer from soil moisture deficiency. Farmers that cultivate on slopes everywhere face similar problems. Conservation technologies may reduce soil and nutrient losses, and thus enhance water holding capacity and soil fertility. But although these technologies promote sustainable crop production on steep slopes, the construction of physical structure such as bench terraces are often labour intensive and expensive to the farmers, since construction and maintenance require high investments. Here we studied the efficiency of coir geotextile with and without crop cultivation in reducing soil moisture deficiency on marginal slopes in Kerala, India. From the results it is evident that the slopes treated with geotextile and crops have the highest moisture retention capacity followed by geotextiles alone, and that the control plot has the lowest moisture retention capacity. As the poor and marginal farmers occupy the highland region, this method provides an economically viable option for income generation and food security along with slope stabilization.

  10. Runoff and drainage water quality from geotextile and gravel pads used in livestock feeding and loafing areas.

    Singh, Anshu; Bicudo, José R; Workman, Stephen R


    Geotextile and gravel pads offer a low-cost alternative to concrete for providing all-weather surfaces for cattle and vehicle traffic, and are used in many livestock facilities to minimize mud, runoff and erosion of heavy traffic areas. The objective of this study was to compare different combinations of geotextile and gravel used in heavy livestock traffic areas that minimize the potential for water pollution. Three different pad combinations were constructed in 2.4 x 6-m plots as follows: (i) woven geotextile+100mm of gravel+50mm Dense Grade Aggregate (DGA); (ii) woven geotextile + geoweb+100 mm DGA; and (iii) non-woven geotextile+152 mm of gravel+50mm DGA; (iv) mud lots as control. The third combination was equivalent to one of the base treatments specified by the Kentucky Natural Resource and Conservation Service (NRCS). All treatment combinations were duplicated. Lysimeter pans were installed in four out of eight plots for the collection of leachate or drainage water. Runoff was collected at the lower end of the plots. About 14 kg of beef cattle manure were added evenly to the plots. Rainfall at 50mm/h was applied using rainfall simulators. In the first five of ten experiments, manure was removed from the surface of the pads after each experiment. In the remaining five experiments manure accumulated on the surface of the pads. The effect of pad treatment was significant on the electrical conductivity (EC), total solids (TS), chemical oxygen demand (COD), nitrite (NO2-N), total nitrogen (TN) and total phosphorus (TP) values in surface runoff at the 5% level. Manure removal did not have any significant effect on the nutrient content of runoff or leachate samples except for ammonia (NH4-N) values. Although a mass balance indicated relatively small amounts of organic matter and nutrients were lost by runoff and leaching, the actual contamination level of both runoff and leachate samples were high; TP levels as high as 12 mg/l (5.4 mg/m2) in runoff and nitrate (NO3

  11. Ensayo experimental de la relación de gradiente para determinar el potencial de colmatación de un sistema suelo-geotextil

    Ernesto A. Parra P.


    Full Text Available Es bien conocida, por la ingeniería geotécnica, la necesidad de drenar cuanto más sea posible las masas coluviales para mantenerlas en equilibrio y disminuir la reptación de éstas. Como estrategia rutinaria para mejorar la estabilidad de estos taludes, se utilizan geotextiles como medio filtrante para el desarrollo de sistemas de drenaje. Es sabido que la correcta selección del geotextil candidato, no debe depender de las presiones comerciales ejercidas, sino de la aplicación metodológica de procedimientos de diseño, para definir unas condiciones de operación del sistema y evitar que el medio filtrante, en este caso el geotextil, se colmate o tapone con las partículas finas del suelo. Como resultados de este trabajo, se definen los riegos de colmatación de dos tipos de geotextiles, con diferentes suelos, encontrándose diferencias apreciables en su comportamiento, como resultado, se obliga a los diseñadores, que usen geotextiles, a tener en cuenta los dos en “Evaluation of geotextile filter behavior using the gradient ratio test” por Jonathan Fannin, Yoginder Vaid y P. Shi. Posteriormente se realizaron ensayos para evaluar el potencial de colmatación de varios sistemas suelo- geotextil e inferir las condiciones más favorables bajo las cuales la colmatación disminuye. Para llevar a cabo esta investigación se adoptó la metodología de ensayo propuesta por la ASTM D 5101-90, referida en el manual instructivo para el uso del permeámetro. La investigación está limitada a 8 tipos de suelo encontrados en la sabana de Bogotá susceptibles de ser utilizados con geotextiles (tejido de trama inserta y no tejido punzonado por agujas en la construcción de obras civiles con aplicaciones filtrantes. Seis de estos suelos fueron utilizados para la calibración del permeámetro. Las propiedades de los suelos y los geotextiles empleados se encuentran especificadas en el numeral cuatro de este trabajo. La utilidad de este proyecto radica en

  12. Use of geotextile tubes with chemical amendments to dewater dairy lagoon solids.

    Worley, J W; Bass, T M; Vendrell, P F


    Three geo-textile filtration tubes were used to dewater lagoon solids from a first stage dairy lagoon using chemical amendments (aluminum sulfate and a polymer) to enhance the separation process. This experiment had previously been done without chemical amendment. The chemical amendments speeded the dewatering process so that filling could be accomplished sooner, and also increased the removal rate of nutrients, especially phosphorus into the solid phase. Chemically amended slurry was pumped from the lagoon into the tube with the filtered liquid seeping from the tube and returning to the lagoon. Each tube was filled five to six times at 2-5-day intervals, and then allowed to dewater for 2 weeks before sampling the solid fraction in the tube. Separation efficiency improved from 79% to 99% for phosphorous and from 92% to 100% for organic nitrogen with chemical amendment. Time required for dewatering was significantly reduced by chemical amendment. Cost for the tube was approximately $10/m(3) of recovered solids with no chemical amendment and cost including the chemicals was approximately $14/m(3) of recovered solids.

  13. Simple systems for treating pumped, turbid water with flocculants and a geotextile dewatering bag.

    Kang, Jihoon; McLaughlin, Richard A


    Pumping sediment-laden water from excavations is often necessary on construction sites. This water is often treated by pumping it through geotextile dewatering bags. The bags are not designed to filter the fine sediments that create high turbidity, but dosing with a flocculant prior to the bag could result in greater turbidity control. This study compared two systems for introducing flocculant: passive dosing of commercial solid biopolymer (chitosan) and injection of dissolved polyacrylamide (PAM) in a length of corrugated pipe connected to the bag. The biopolymer system consisted of sequential porous socks containing a "charging agent" followed by chitosan in the corrugated pipe with two levels of dosing. The dissolved PAM was injected into turbid water at a flow-weighted concentration at 1 mg L(-1). For each treatment, sediment-laden turbid water in the range of 2000 to 3500 nephelometric turbidity units (NTU) was pumped into the upstream of corrugated pipe and samples were taken from pipe entrance, pipe exit, and dewatering bag exit. Without flocculant treatment, the dewatering bag reduced turbidity by 70% but the addition of flocculant increased the turbidity reduction up to 97% relative to influent. At the pipe exit, the low-dose biopolymer was less effective in reducing turbidity (37%) but it was equally effective as the high-dose biopolymer or PAM injection after the bag. Our results suggest that a relatively simple treatment with flocculants, either passively or actively, can be very effective in reducing turbidity for pumped water on construction sites.

  14. The Underwater Geotextile Laying Process of a Navy Engineering%海军某工程水下土工布铺设工艺



    土工布铺设为海军某工程堤身首道工序,该工程位于开敞、无遮掩海域,施工难度较大。本工程采用小锚牵引土工布边铺设边压载的施工工艺,对以后类似无掩护水域土工布铺设施工有一定的参考价值。%The geotextile laying as the first process of navy engineering. The project is located in the open and exposed area with difficult construction. This project takes the con-struction technology of smal anchor drawing laying geotextile side bal ast, which has a certain reference value for the no cover similar waters geotextile laying construction for future.

  15. Ensayo experimental de la relación de gradiente para determinar el potencial de colmatación de un sistema suelo-geotextil


    Es bien conocida, por la ingeniería geotécnica, la necesidad de drenar cuanto más sea posible las masas coluviales para mantenerlas en equilibrio y disminuir la reptación de éstas. Como estrategia rutinaria para mejorar la estabilidad de estos taludes, se utilizan geotextiles como medio filtrante para el desarrollo de sistemas de drenaje. Es sabido que la correcta selección del geotextil candidato, no debe depender de las presiones comerciales ejercidas, sino de la aplicación metodológica de ...

  16. The development of kenaf ecological geotextile of China%我国红麻生态土工布的发展

    肖鸽; 闫星月; 谢光银


    The concept of industrial geotextile, classification and function were introduced.The kenaf geotextile in the application and development status at home and abroad were analyzed.The development prospects of 3D kenaf fabric were predicted.%简述产业用土工布的概念、分类及功能,分析红麻土工布在国内外的应用与发展现状,展望红麻三维立体织物的发展。

  17. Application of Geotextiles in Embankment Project%土工布在堤围工程中的应用



    通过珠江三角洲工程实践,总结了土工布在堤围工程中的应用技术,而且广泛应用于新建、维护堤围及航道整治工程中。%Based on the practice of project in the Pearl Delta, the author summarizes the application technique of geotextiles used in the embankment project. This technique has been widely used in the embankment construction and maintenance works and channel regulation project.

  18. Sorption of heavy metals on a chitosan-grafted-polypropylene nonwoven geotextile

    Vandenbossche M.


    Full Text Available This work describes the development of an environmental friendly functionalized polypropylene nonwoven geotextile (PP in order to trap heavy metals in sediments and sludges. Chitosan was chosen as the sorbent because of its ability to trap heavy metals, of its natural origin (from shells, and of its low cost. PP was first functionalized with acrylic acid using a cold plasma process, in order to bring some reactive carboxylic functions onto the surface. Chitosan was then covalently grafted on the acrylic acid modified polypropylene. The functionalized surfaces were characterized by FTIR (Fourier Transform InfraRed and chitosan was thus proven to be grafted. The ability of the functionalized textile to trap heavy metals was then investigated. Copper was chosen as the model heavy metal, and artificial solutions of CuSO4 were prepared for the experiments. Sorption studies among the concentration of copper in polluted solutions at 20°C were carried out with PP-g-AA-chitosan (Polypropylene-grafted-Acrylic acid-chitosan in order to evaluate the maximum of absorption of this surface: the textile can chelate copper increasingly with the initial copper concentration until 800 ppm where it reaches a plateau at about 30 mg/L. The effects of pH and of the ionic strength (absorption in a NaCl containing solution were finally investigated. The trapping of Cu2+ decreases slowly when the ionic strength increases. For a seawater-like NaCl concentration of 30g/L, the textile still chelates about 20 mg/L of Cu2+. Finally, the optimum pH to trap the maximum amount of copper was determined to be 4.75, which corresponds to the optimum pH for the solubility of the chitosan.

  19. Monitoring tools for assessing the effectiveness and resilience of geotextile-supported soil bioengineering systems - a conceptional approach

    Obriejetan, Michael; Rauch, Hans Peter


    Geotextile-supported systems are widely accepted as a convenient facility for erosion control measures. Technical auxiliaries such as geotextiles are typically used where difficult site conditions and human interventions, as a result of construction activity, require instant protection until its tasks as erosion-resistant layer can be assumed by vegetation. However, erosion control within an initial phase is directly related to restoration techniques whereas vegetation plays a major role for sustainable slope protection. To obtain desired system development over time, periodic monitoring can serve as quality assurance as well as economically viable resource. Practice shows that in-time interventions and maintenance activities have been more successful with regard to vegetation development and economic feasibility than missing supervision strategies. From the maintenance personnel perspective, monitoring tools are required to be designed for easy and valuable handling and processing. On that account specific tools for assessing the functional capacity of combined erosion control measures have been developed. One of these tools takes advantage of digital image processing for analyzing vegetation cover in a simple but effective way. Another tool serves as classification appliance based on condition data input (e.g. degree of vegetation cover, erosion damage) to gain automated reference concerning system status, resilience and presumable future development. Beside system assessment these appliances may be considered as contribution to quality improvement and sustainable ecosystem restoration and slope protection. At the conference the practical application and of these tools are demonstrated and its substantial advantages are displayed.

  20. 土工织物有效孔径测定方法探讨%Determination methods for effective opening size of geotextiles

    苏树清; 吴伟俊


    对土工织物有效孔径的试验方法进行阐述、对短纤针刺非织造土工布进行有针对性比对试验分析,对有效孔径的试验方法进行了探讨。干筛法适用于编织土工布,湿筛法由于更能直接模拟工程工作特性,适用于包括非织造土工布在内的所有类型的土工织物。%The determination methods for the effective opening sizeof geotextiles and geotextile-related products are discussed. They include wet sieving method and dry sieving method. Through comparison and analysis of the test data, the dry sieving method, is applicable to woven geotextiles, and the wet sieving method can be used for all the geotextiles in duding non woven geofabrics.

  1. Variation of crack intensity factor in three compacted clay liners exposed to annual cycle of atmospheric conditions with and without geotextile cover.

    Safari, E; Jalili Ghazizade, M; Abduli, M A; Gatmiri, B


    Performance of compacted clay liners commonly used as landfill barrier systems can be subject to decline in terms of hydraulic conductivity if left exposed to atmospheric conditions for an extended period of time prior to placement of overlaying layers. The resulting desiccation cracking can lead to increased hydraulic conductivity. Desiccation crack intensity was studied for three clayey soils commonly used for construction of landfill barrier system in a relatively large scale test setup exposed to real time atmospheric conditions over a complete annual cycle. A white separator geotextile cover was presumed to be capable of reducing the intensity of desiccation cracking through absorbing and maintaining higher amounts of moisture and reducing the temperature of the soil surface in comparison to a directly exposed soil surface. Desiccation cracking was monitored using a digital imaging technique for three compacted clay liners in two sets, one open to air and the second covered with the white geotextile. Crack intensity factor approached a relatively stable phase after certain cycles corresponding to atmospheric dry wet cycles. The results indicated that the white separator geotextile was capable of reducing the crack intensity factor by 37.4-45.9% throughout the experiment including the cyclic phase of desiccation cracking. During the stable phase, the maximum reduction in crack intensity factor of 90.4% as a result of applying geotextile cover was observed for the soil with the lowest plastic index and clay content and therefore the lowest magnitude of crack intensity factor. The other two soils with similar clay content but different plastic index showed 23.6% and 52.2% reductions in crack intensity factor after cyclic phase when covered with geotextile.

  2. 温度对丙纶机织土工布性能的影响%The Influence of Tempreture on the Performance of Woven Geotextile Fabric with Polypropylene Fibre

    钱程; 储才元


    In order to research the influence of tempreture on theperformance of woven geotextile fabric with polypropylene fibre,a series tests and analyses on polypropylene knitting geotextile fabric and polypropylene filament woven geotextile fabric were carried on,the result showed that,with the increasing of tempreture,the shrinkage rate of polypropylene woven geotextile fabric was continuously increased,the tenacity was increased first,and then decreased.%为了研究温度对丙纶机织土工布性能的影响,对丙纶扁丝和丙纶长丝机织土工布进行了一系列测试和分析。表明:随温度升高,丙纶机织土工布的收缩率不断增加,而强度先升高、后降低。

  3. 土工织物双向可拉伸多功能渗透试验装置%Multifunctional permeability test apparatus for geotextiles under biaxial tension

    雷国辉; 吴纲; 姜红; 茅加峰


    为揭示土工织物工程应用时处于拉伸状态下的渗透和反滤特性,自主研制了一套多功能渗透试验装置。采用两套独立的、稳定可靠的砝码和杠杆加载机构,可以实现土工织物在单向和双向不同拉伸应力作用情况下的渗透试验。设计开发了一种多功能渗透仪,可以开展纯土工织物以及覆土土工织物在垂向无压和有压情况下的常水头和变水头渗透试验。初步应用结果表明,该试验装置在土工织物无拉伸和无垂向压力情况下的渗透试验结果与满足国标和国际标准要求的渗透仪的试验结果基本一致,且能够实现试验装置设计的所有功能,为后续开展土工织物拉伸条件下渗透和反滤特性的试验研究奠定了基础。%A multifunctional permeability test apparatus is developed to investigate the permeability and filtration properties of geotextiles under tension as encountered in practice. By adopting two individual sets of stable and reliable counterweight-and-lever loading assemblies, permeability tests can be carried out for geotextiles under either uni-axial or biaxial tension with different tensile stresses. A multifunctional permeameter is designed and developed for performing constant head and falling head permeability tests on geotextiles or soil-covered geotextiles with and without vertical load. The preliminary experimental results show that the permeability of geotextiles without tension and vertical load obtained from the newly developed apparatus is generally consistent with that obtained from a permeameter conform to the national and international standards. Moreover, all functions designed for this apparatus can be accomplished. This provides a basis for future studies on the permeability and filtration properties of geotextiles under tension.

  4. Property and Application of Polypropylene Filament Nonwoven Geotextiles%丙纶长丝非织造土工布的性能及其应用

    黄顺伟; 钱晓明; 周觅


    The production technology status of polyester and polypropylene filament was introduced.The chemical resistance,me-chanical properties,punctures resistance and performance of asphalt impregnated of polyester and polypropylene nonwoven geotextiles were comparative analyzed.The application prospect of polypropylene filament nonwoven geotextile was proposed..%简述了涤纶和丙纶长丝的生产技术现状,比较分析了涤纶与丙纶非织造土工布的耐碱性、力学性能、抗穿刺性及沥青浸渍后性能,以及丙纶长丝非织造土工布的应用前景。

  5. Mechanism of Geotextile Reinforcement and its Experimental Research%土工织物加固机理及其实验研究

    陈明雄; 何皎皎; 杨米加


    The non-equal force is produced in different layers of geotextileused in dam in the process of geotextile reinforcement, and the effect of different part or different layer is also different. So it is necessary to analyze the interaction of geotextile and soil. Due to this, the relation of the stressdisplacement status of geotextile and its interaction with soil is constructed, and the experimental research is also performed.%由于土工织物加筋过程中每层土工织物的受力并不均匀,并且各层土工织物所起的作用并不相同,有必要进行土工织物与土的相互作用分析。正是考虑这一点,首先建立了变形过程中土工织物的受力状态及其和土的共同作用的关系,并进一步进行了实验验证。

  6. Design and calculation methods of geotextile tubes%土工织物充填管袋设计计算方法研究

    刘伟超; 杨广庆; 汤劲松; 赵玉


    土工织物充填管袋是土工包裹系统的一种,它用编织土工布缝合而成,再用高压泥浆泵充填砂浆,最终形成管状袋体,优点众多,可用于堤坝填筑、抗洪抢险等工程中,应用前景广阔。但目前关于土工管袋形状、高度、张力等参数的计算方法主要是针对高充填压力情况的,而中国实际工程中较多的是充填压力较低即袋体扁平的情况,因此针对目前研究的不足,提出现有无量纲计算方法的适用条件,并对其进行改进,提出低充填压力下的袋体特性计算方法并进行验证,计算结果被制成图表,方便实际应用时查找参数。%Geotextile tube is one kind of the geotechnical package system. It is made of woven fabric, filled with the mortar by high-pressure mud pump, and eventually becomes a tube. The geotextile tube has many advantages and wide application prospects, and it can be used for building dams and flood prevention projects. The existing theoretical calculation methods have good applicability to calculate the shape, height, tension and other parameters of geotextile tubes under the situation of high filling pressure. However, they are not suitable for the situation of low filling pressure. As the geotextile tube applied in China is often flat, and the filling pressure is low. The applicable conditions of the current dimensionless method are proposed, and the method is proved to calculate the parameters of the geotextile tube with low filling pressure. The equations are solved by numerical integration, and the results are verified and formed into charts. Thus it is easily to find the value of the parameters in actual applications.

  7. Simulation of Geotextile Filter Analysis Based on Particle Flow Code%模拟土工织物反滤作用的颗粒流分析方法

    李伟; 赵坚; 沈振中; 杭学军; 张松


    Particle flow code (PFC) method is used to establish the geotextile filter numerical model. And the particles moving characteristic and influencing factors hostaged by water in soil with geotextile filtration structure is analyzed from micromechanics level. The calculation errors of PFC application in numerical simulation of geotextile filter is discussed and the solution method is put forward. Under the influence of multi-factors, the porosity sensitivity of the geotextile particles flow filtration model is analyzed by using orthogonal test. Finally, it further verifies the permeability coefficient "peak" phenomenon in geotextile clogging test and its causes.%利用颗粒流(PFC)方法建立了土工织物PFC反滤模型,从细观层面分析了具有土工织物反滤结构的土体中水流挟持颗粒移动的特点及影响因素,探讨了PFC方法应用中引发的误差问题,并提出了解决方案.通过正交试验法分析了多因素影响下土工织物颗粒流反滤模型的孔隙率变化敏感性,进一步验证了土工织物淤堵试验中出现的渗透系数“峰值”现象及其产生的原因.

  8. Cysteine-grafted nonwoven geotextile: a new and efficient material for heavy metals sorption--part A.

    Vandenbossche, M; Casetta, M; Jimenez, M; Bellayer, S; Traisnel, M


    Cysteine is an interesting biomolecule in the heavy metals trapping field, thanks to its amino, thiol and carboxylic groups. This amino acid is indeed present in some natural chelating agents: glutathione, phytochelatins and metallothioneins. However, cysteine has never been used in remediation processes. When immobilized on a polypropylene nonwoven (PP) geotextile, an innovative and eco-friendly material is obtained, with potential use in drainage and filtration of wastewaters and sediments. PP was first functionalized with acrylic acid using a low pressure cold plasma process to bring reactive carboxylic functions onto the surface (PP-g-AA). Cysteine was then covalently grafted on this modified PP. The cysteine grafting on PP-g-AA was optimized using response surface methodology, which allowed concluding that the best conditions of immersion without heating consist in: a solution containing 0.229 mol/L of cysteine for 28 h. The materials were characterized by Scanning Electron Microscopy, InfraRed Spectroscopy and X-ray Photoelectron Spectroscopy: evidence of covalent cysteine grafting was given. Preliminary sorption tests at 20 °C and pH = 4.5 with artificially polluted solutions give promising results for divalent heavy metal ions: 95 mg Cu (II) (CuSO4 solution), 104 mg Cu (II) and 135 mg Pb(II) (with NO3(-) counter-ion) per gram of PP are trapped.

  9. 土工布在水泥混凝土路面加铺沥青层中的应用%Application of geotextile in cement concrete pavement paving asphalt layer



    Combining with the application of geotextile in the construction of Gui-Liu highway pavement paving asphalt layer, this paper detailedly elaborated the application of geotextile in cement concrete pavement paving asphalt concrete surface layer, emphatically introduced the materi- al properties and construction technology of geotextile, accumulated valuable experience for future similar projects construction.%结合土工布在桂柳高速公路路面加铺沥青层工程的应用,详细阐述了土工布在水泥混凝土路面加铺沥青混凝土面层中的应用,着重介绍了土工布的材料特性和施工工艺,为今后同类工程施工积累了宝贵经验。

  10. Experimental study on geotextile envelope for subsurface drainage in Yellow River Delta%黄河三角洲暗管排水土工布外包滤料的试验研究

    刘文龙; 罗纨; 贾忠华; 卜凡敏; 潘延鑫; 唐双成; 袁黄春; 李山


    In recent years, subsurface drainage has been greatly advocated in the Yellow River Delta area for salinity control and land reclamation. With the very uniform textured silty sand as major soils in the Yellow River Delta, and lacking of gravel envelope material, there is an urgent need to select proper synthetic envelope for subsurface drainage construction in the area. Proper selection of envelope materials is critical for a subsurface drainage system construction. Geotextile envelope has multiple advantages, including good water conductivity, retaining soil particles from clogging the drains, low cost and convenience for mechanical construction. Thus geotextile envelope is widely used in subsurface drainage system constructions throughout the world. In China, however, very few subsurface drainage projects used geotextiles as envelope materials for various reasons. Therefore, geotextile envelope may find its wide application in many poorly drained areas, such as the Yellow River Delta in China provided that proper selection criteria are met. Based on soil particle size analysis and theoretical calculations, this paper presents an experimental study on geotextile material used for subsurface drainage envelope in the Yellow River Delta, China. A testing permeameter was built on the basis of existing literature-Materials for subsurface drainage system (IDP 60). The selection criteria have three major factors, including thickness, permeability and O90. After analyzing the soil particle size distribution and measuring the saturated hydraulic conductivity (Ks) with the falling head method, we chose two types of geotextiles as the tested samples. One of these geo-textiles (Geotextile A) has a larger O90 than that in the criterion by IDP 60, while the other one (Geotextile B) meets the criterion. With these essential information, we conducted a series of experimental studies to evaluate the performance of geotextiles in filtration, permeability and anti-clogging. After

  11. Research and development of test system for geotextile expansion rupture performance%新型土工布胀破性能测试系统的研制

    李伟锋; 孙启晓; 李想


    In order to reduce the test error caused by disk deformation when geotextile expansion rupture occurs, a program for testing the expansion rupture performance of geotextile based on disk correction was proposed. The testing principle, software flow chart of the total system and hardware block diagram were presented. The system uses a motion control card to control the motor drive section, and the signal acquired by the sensor was input to the computer for processing via the data acquisition card. The data obtained was processed by the digital filter so that real-time display of data and graphs was realized during testing. The experimental results demonstrate that the system reduces test error caused by disk deformation when geotextile expansion rupture occurs.%为减小土工布胀破时膜片变形造成的测试误差,提出一种基于膜片补偿的土工布胀破性能测试方案.给出了系统测试原理、软件系统总的流程图及硬件测试系统框图.系统使用运动控制卡控制电动机驱动部分,由传感器采集得到的信号通过数据采集卡输入计算机处理,对得到的数据采用数字滤波,实现了测试过程数据和图表的实时显示.依据试验数据对结果进行分析,结果证明系统减小了由于土工布胀破时膜片变形造成的测试误差.

  12. Apparatus and Method of Geotextile Tensile Testing%土工织物拉伸试验测试仪器及方法

    黄文彬; 任泽栋; 曹明杰


    抗拉强度及延伸率是评价土工织物拉伸性能的主指标,抗拉强度试验测试结果的有效性直接影响到对工程实践的指导。通过对国内外各种有关土工织物拉伸试验研究成果的总结,对各种测试方法给予了客观的分析,并在此基础上提出了土工织物多向拉伸的设想。结合工程实际,从理论可行的角度设计了两种多向拉伸试验仪器,对土工织物拉伸试验测试方法的改进提供了参考依据。%Abstract: The tensile strength and elongation are key performance indicators of geotextile,and the effectiveness of the tensile strength test method has a direct impact on engineering practice guidance. Various of relevant geotextile tensile test results from domestic and foreign have been summarized, while an objective analysis was given to those methods, and on basis of this came to the idea of multi - directional tensile test. Based on engineering practice, two multi - directional tensile test instruments are designed from the point of theory. All those will provide a reference to the improvement of test methods for geotextile tensile test.

  13. Use of geotextiles for mitigation of the effects of man-made hazards such as greening of waste deposits in frame of the conversion of industrial areas

    Bostenaru, Magdalena; Siminea, Ioana; Bostenaru, Maria


    The city of Karlsruhe lays on the Rhine valley; however, it is situated at a certain distance from the Rhine river and the coastal front is not integrated in the urban development. However, the port to the Rhine developed to the second largest internal port in Germany. With the process of deindustrialisation, industrial use is now shrinking. With the simultaneous process of the ecological re-win of rivers, the conversion of the industrial area to green and residential areals is imposed. In the 1990s a project was made by the third author of the contribution with Andrea Ciobanu as students of the University of Karlsruhe for the conversion of the Rhine port area of Karlsruhe into such a nature-residential use. The area included also a waste deposit, proposed to be transformed into a "green hill". Such an integration of a waste deposit into a park in the process of the conversion of an industrial area is not singular in Germany; several such projects were proposed and some of them realised at the IBA Emscher Park in the Ruhr area. Some of them were coupled with artistic projects. The technical details are also subject of the contribution. Studies were made by the first two authors on the conditions in which plants grow on former waste deposits if supported by intermediar layers of a geotextile. The characteristics of the geotextiles, together with the technologic process of obtaining, and the results of laboratory and field experiments for use on waste deposits in comparable conditions in Romania will be shown. The geotextile is also usable for ash deposits such as those in the Ruhr area.

  14. 土工织物施工期内强力保持浅析%Analysis of geotextile strength retention situation during construction

    郭伟玲; 刘军


    In this paper, according to the research of aging property, colmation performance and the perfor-mance of plastic drainage plate after construction for non-woven geotextile, the filling sand bags used in Zhanjiang Port land formation cofferdam were studied as research subjects. After three months, the strength index test of poly-propylene non-woven geotextile at different locations of the cofferdam was carried out. The data analysis shows that water can protect geotextile from aging. According to regional annual sunshine, radiation and the other climatic con-ditions, the coefficient of optical oxygen aging effects can be calculated.%通过对无纺布老化性能、於堵性能及塑料排水板工后性状的研究,对湛江某港区陆域形成围堰工程使用的充填砂袋为样本进行研究,3个月施工期后,对处于围堰不同位置的聚丙烯编织土工布进行强力指标试验。通过分析数据发现,若要满足强力指标保持率的要求可采取浸入水中一定深度进行保护,也可结合地区年日照、辐射量等气候条件推算光样老化影响。

  15. 基于 ANSYS 的软体排动水沉排受力分析%ANSYS-based Analysis on Actions of Compound Geotextile Being installed in Dynamic Water

    张益智; 张焕岭; 许战军


    软体排因其排布具有隔离、反滤作用及整体具有一定的柔性可适应凹凸不平的地形,材料使用寿命长、施工方便等特点,被广泛应用于河道的护底及护岸、海岸的护滩、泄水建筑物后部的防冲等。在软体排施工中,为了防止沉排时因受力过大导致排体撕裂、铺排船倾覆等的发生,要严格控制软体排船舷处拉力。对于静水中沉排时软体排船舷处拉力的研究,已基本趋于成熟化,有精确的解析解,但对动水中沉排时软体排拉力多采用试验方法得出经验公式来计算。文章在静水中沉排时软体排受力基础上建立动水中软体排计算有限模型,并通过具体算例得出动水中软体排拉力变化的一些规律。%The soft geotextile is widely utilized for bottom protection of river course, river bank protection, sea bank apron and scouring pro-tection of the rear sections of outlet structures as it can play the roles of isolation, filter and flexibility which can satisfy the uneven landforms. This geotextile also features long service life and construction convenience.The tension on the geotextile at shipboard shall be controlled strictly in the geotextile installation so as to avoid the geotextile being torn up or the ship being overturned because of the large tension while the geotextile is being installed.The study on the tension at the shipboard while the geotextile is installed in the static water is becoming ma-ture and precise analysis and calculations are available.But the tension at the shipboard while the geotextile is installed in the dynamic water is calculated by applying the empirical formula which is from test methods.In this paper, the finite element model for calculation of the soft geotextile installation in the dynamic water is constructed based on the action on the geotextile being installed in the static water.Through specific calculation, some laws on variation of action on the

  16. 植物纤维毯对道路边坡微生境的影响%Effect of Geotextile on Road Slope Microhabitat


    In order to better understand the ecological protection function of geotextiles, comprehensively understand the principle of slope protection, and analyze in-depth the advantages of ecological slope protection of geotextiles, the field experiment is carried out on the slope of Shijiazhuang—Anyang expressway . Taking straw mats, coconut mats and straw coconut mats as the experimental object and the non-woven fabric as the control group, we observed the amount of surface runoff, soil erosion volume, surface soil moisture, soil temperature and soil organic matter content, etc. to analyse the influence of different geotextiles on slope microhabitat. The result shows that (1) 3 kinds of geotextile on the microhabitat of the slope have certain improvement, the soil loss from plots covered with the 3 kinds of geotextile decreased obviously, and the amount of surface runoff decreased in straw mats and straw coconut mats;(2) the 3 kinds of geotextile can reduce the surface soil temperature in the high temperature season, and the cooling effect of straw mats is the best;(3) from the view of the surface soil moisture content, the straw coconut mat is more advantageous to the rain water infiltration, resulting in high soil moisture, and the surface soil moisture loss is slow after rain stopped, so that it is more advantageous to the plant growth;(4) the degradation of 3 kinds of geotextile can increase the soil organic matter content, enhance soil fertility, and improve the soil, the effect of the straw mats is the best;(5) the influence of geotextiles on the soil microhabitat is an improvement, it can promote plant growth, especially it can promote the growth of the roots of the plants.%为更好地了解植物纤维毯的生态防护功能,全面认识其护坡原理,深入分析植物纤维毯的生态护坡优势,依托石安(石家庄—安阳)高速公路展开实地边坡试验.以稻草毯、 稻草椰丝混合毯和椰丝毯为试验对象,以无纺布为对照组

  17. Development of biofilm on geotextile in a new multi-zone wastewater treatment system for simultaneous removal of COD, nitrogen and phosphorus.

    Alimahmoodi, Mahmood; Yerushalmi, Laleh; Mulligan, Catherine N


    This study investigated the formation and evolution of biofilm on a fixed cylindrical structure wrapped in geotextile, in a multi-zone wastewater treatment system called BioCAST. The organic, nitrogen and phosphorus loading rates of (OLR) 0.95-1.86 g COD/(m(3)d), (NLR) 0.02-0.08 kg N/(m(3)d), and (PLR) 0.014-0.02 kg P/(m(3)d), were applied. The results demonstrated high removal efficiencies of carbon, nitrogen and phosphorus, reaching 98.9%, 98.3% and 94.1%, respectively, after 250 d of operation. The biofilm biomass showed a fast formation (reaching 54.2g/L) and maximum phosphorus content of about 7% (dry basis). Biofilm demonstrated the ability to remove phosphorus, and its characteristics correlated with nitrogen and phosphorus removal rates. The geotextile material with filamentous structure causing rapid attachment and formation of biofilm can solve many problems encountered in conventional attached-growth wastewater treatment systems such as slow start-up, low reactor biomass content and low capacity to handle high organic loading rates.

  18. Application of Geotextile in Expressway Construction%土工织物在高速公路施工中的应用



    Geotextile has been widely used in expressway engineering for the advantages of high intensity, good corrosion resistance, low cost and being convenient for construction. It can have the effect of filtra-tion, drainage and reinforcement. This paper, based on the engineering example, summarizes the con-structing technology of geotextile in soft highway foundation, evaluates the engineering effects, which pro-vides reference for similar engineering.%土工织物具有强度高、耐腐蚀性能好、抗化学侵蚀性能好的特点,同时施工操作方便,工程造价低,因此广泛用于高速公路工程中,主要可以起到过滤、排水、加筋补强的作用。结合具体的工程实例,对土工织物在公路软基中的施工技术进行了总结,对工程效果进行了评价,为同类工程提供了参考。

  19. Study on properties of long polyester staple fiber needle-punched nonwoven geotextile%超长涤纶短纤维针刺土工布性能研究

    李素英; 张瑜; 范立元; 任煜; 顾闻彦; 于树发


    The needle-punched nonwoven geotextile was made using PET fibers of 51, 65 and 150 mm.The influence of process parameters such as length of the fiber , punching density and depth of needle penetration on mechanical properties , thickness and vertical permeability coefficient of geotextile was discussed .The results show that the mechanical properties of the nonwoven geotextile increased significantly with the increase of the PET fiber length .The reasonable choice of the process parameters could enhance the mechanical and hydraulic conductivity properties of the nonwoven geotextile .%以长度为51、65和150 mm的涤纶短纤维为原料,采用非织造针刺技术加工制得土工布。研究了原料纤维长度、针刺密度和针刺深度对土工布力学性能、厚度、垂直渗透系数的影响。结果表明:增加土工布原料纤维长度可以明显提高土工布力学性能;合理地选择针刺深度和针刺密度,有助于提高土工布的力学性能及透水性能。

  20. Application of Geotextiles in Jiepai Waterway Regulation Engineering of the Yangtze River%土工织物在长江界牌航道整治工程中的应用

    李国祥; 胡义龙


    通过长江界牌航道整治工程实例介绍土工织物在航道整治工程中的应用情况。%Based on the practical example of Jiepai Waterway Regulation Engineering of the Yangtze River, it introduces the application of geotextile in waterway regulation engineering.


    刘丽芳; 王卫章; 储才元; 迟景魁


    在过滤排水系统中,孔径及其分布是非织造土工布的重要指标,它与非织造土工布的渗透性能直接相关.利用Poisson Polyhedron理论,在前人研究的基础上分析了非织造土工布的理论孔径分布及其最大孔径,并根据Hagen-Poisseuille定律探讨了非织造土工布的孔径分布与其渗透性能间的关系,理论计算的垂直渗透与实测结果有较好的一致性.%In the field of filtration and drainage,pores size and their distribution of nonwoven geotextile are the most important parameters,which are directly related to its permeability.Based on the former researchers' works,the theoretical pore size distribution and maximum pore size of nonwoven geotextile are studided by means of Poisson polyhedron theory.The relation berween pore size distribution and permeability of nonwoven geotextile is derived by using Hagen-Poisseuille Law.The theoretical calculation value of vertical permeability coefficient is approximately agreeable to the expetimental result for a nonwoven geotextile sample.

  2. 土工袋减振隔振机制分析及试验研究%Mechanism analysis and experimental study of vibration reduction and isolation effect of geotextile bag

    刘斯宏; 高军军; 王艳巧


    Geotextile bag buried in subgrade can improve the bearing capacity of subgrade and also reduce or isolate vibrations. A series of horizontal cyclic shear tests are carried out to investigate the dynamic characters of piled geotextile bag. The test results indicate that geotextile bag is excellent materials for base vibration reduction and isolation as it has variable horizontal stiffness and large damping ratio. The damping ratio of geotextile bag decreases with increasing of vertical pressure, and increases with the increasing of maximum shear strain. Besides, the discrete element analysis is carried out on a geotextile bag under cyclic loading. The contact between soil particles in geotextile bag is modeled as a spring-dashpot system. The geotextile bag is modeled as coating of small particles with tension. The contact between the small particles in coating is also spring-dashpot system which has no tangential contact but only normal contact, and can only carry tension stress. The simulation results illustrate that the vibration reduction of geotextile bag is due to the energy dissipation mainly resulting from frictional and viscous forces among soil particles and the tension of bag. Moreover, in-situ tests are performed on a trench built with geotextile bag to validate the vibration reduction and isolation effect of geotextile bag.%设置于地基中的土工袋不仅可以提高地基承载力,而且具有减振隔振效果。通过水平循环剪切试验研究了土工袋的动力特性,验证了土工袋具有可变的水平刚度和较大的阻尼比,表明土工袋是一种良好的基础减振隔振材料。土工袋的等效阻尼比随着竖向压力的增大而减小,随着最大剪应变的增大而增大。同时,采用离散单元法进行了土工袋在动力荷载作用下的数值模拟计算,土颗粒间采用弹簧-阻尼器接触模型;而土工袋被看成具有张力的小颗粒薄层,这些小颗粒间的接触与袋内土




    双层土工织物既有良好的过滤性能又有足够的机械性能,是很有发展前景的一种新型土工滤材.本文重点探讨了其过滤性能,得到了过滤性能与织物结构、纤维线密度及各个单层之间的关系.%Double-layered geotextile are very promising filtration material used in drainage field,for they have excellent filtration property as well as enough mechanical strength.In this paper,their filtration property are discussed mainly,and some significative results have been got.

  4. Discussion on level drainage property of nonwoven geotextiles in tunnel engineering%隧道工程非织造土工布的水平排水特性探讨

    蒋雅君; 杨其新; 刘东民; 盛草樱


    根据非织造土工布的结构特点、隧道工程的环境条件,基于非织造土工布水平方向的多孔介质模型与水平排水试验,对非织造土工布在水平方向上的排水特性进行了分析和探讨.模型分析表明,其2个重要影响参数等效孔径r、孔隙数目N会受非织造布的规格、外界法向压力等因素的影响发生变化;水平排水试验结果也表明,虽然单位面积质量高的无纺布等效过水面积大,但由于其等效孔径小且孔隙数量多,造成过水截面中的孔隙总周长大,使其水平排水能力降低.%The level drainage property of nonwoven geotextiles was analyzed and discussed based on porous medium model of level direction and level drainage experiments according to the microstructure features of nonwoven geotextiles and environmental conditions of tunnel engineering. The analyses to the porous medium model shows that two important parameters (equivalent aper-turerr and number of pores N) of the model will adjust to suit the change of plane unit mass of nonwoven geotextiles and normal pressure on it. The level drainage experiments also show that although the nonwoven geotextiles with high plane unit mass has bigger equivalent flow area, its level drainage capability is lower because its equivalent circumference is longer according to the smaller equivalent aperture and more numbers of pores of the level flow section.

  5. Environment-friendly Dredging with Geotextile Tubes for Dewatering and Volume Reduction of Sediments in Lake and Reservoir%环保疏浚联合土工管袋用于湖库底泥的脱水减容

    王松; 魏新庆; 王立彤


    The engineering case of using environment-friendly dredging with geotextile tubes for dredging, dewatering and volume reduction of sediments in Hangu Sewage Reservoir is introduced. It mainly includes design of environment-friendly dredging, preparation of dewatering and volume reduction site, selection of the geotextile tubes, filling of geotextile tubes, dosing of the flocculant and so on.Through the design and whole process practice of this engineering, the design parameters and process of environment-friendly dredging with geotextile tubes for dewatering and volume reduction of sediments in lake and reservoir are found to lay the foundation for its large-scale application in the future.%介绍了汉沽污水库现场试验工程采用环保疏浚联合土工管袋的方式,对底泥进行清淤和脱水减容的工程实例,主要内容包括环保疏浚设计、脱水减容场地准备、土工管袋选型、土工管袋充填、絮凝剂投加等.通过对本工程的设计和全过程跟踪实践,摸索出环保疏浚联合土工管袋用于湖库底泥脱水减容的设计参数和操作流程,为今后规模化应用奠定了基础.

  6. Test on Embankment Built with Hydraulic Filled Geotextile Bags of Sea Sludge with Cement Additive%吹填海泥掺水泥充灌模袋筑堤试验

    吴月龙; 朱方方; 陈东东; 张红


    Embankment construction is an essential part of the reclamation ,using geotextile bags filled with reclamation sea sludge for embanking is a new method .In the field test geotextile bags filled with sea sludge which was mixed with cement was used to build the embankment .The monitoring data of the settlement ,lateral displacement and pore pressure could meet the design requirements .At the same time ,the drainage characteristics of geotextile bags and strength proper-ties of the mixture of reclamation sea sludge and cement were analyzed through model tests of different sludge weights and different cement ratio .The test results indicate that embankment using geotextile bags filled with the mixture solidifies and consolidates faster with obvious effects than that of other methods .%围堤建设是围海造陆工程中必不可少的一部分,采用充淤泥模袋筑堤是一种新兴施工方法。现场试验采用吹填海泥掺加一定比例固化剂(水泥)充填入土工模袋进行筑堤,沉降、侧向位移及孔压等监测数据均能满足设计要求。同时,通过不同泥浆比重、不同水泥掺入比的模型试验分析了模袋的排水特性、掺固化剂海泥的强度特性。试验结果显示,吹填海泥掺水泥充灌模袋筑堤工法筑堤淤泥固结快,效果明显。

  7. Application Study on Geotextile as Bond-Breaking Layer Between Concrete Pavement Slab and Lean Concrete Base%土工布作水泥混凝土路面隔离层应用研究

    林天干; 姚佳良; 于远征; 袁剑波


    主要结合广东、湖南等省高速公路中采用土工布作水泥混凝土路面隔离层进行的路面层间力学性能试验与工程应用研究,探讨了贫混凝土基层上铺筑水泥混凝土面层时采用土工布隔离层与无隔离层时的层间力学性能差别.通过现场试验路施工,总结了土工布用于路面隔离层的施工控制技术.获得的土工布隔离层层间力学性能参数与施工应用技术,为实体工程路面设计、施工控制提供了科学依据.%This research explored the difference in mechanical performance of slab-base interface between the pavements without a bond-breaking layer and the pavements with geotextile as the bond-breaking layer installed between the concrete pavement surface slab and the lean concrete base, via the field tests for mechanical performance of slab-base interface treated with geotextile as the bond-breaking layers in some highway projects of Hunan and Guangdong Provinces. The techniques of construction control in placing geotextile atop the lean concrete base as the bond-breaking layer is concluded from the construction of the field test roads. The mechanical performance of slab-base interface with geotextile as the bond-brea king medium derived from this research and the techniques of construction offer scientific reference to pavement design and construction control in the practical road engineering projects.

  8. Study on characteristics of spunbond PET and PET staple fiber needlpunched geotextiles%涤纶纺黏与涤纶短纤维针刺土工布的性能研究

    崔凯; 靳向煜


    测试了涤纶纺黏针刺土工布和涤纶短纤维针刺土工布的各项力学性能指标,研究了两种土工布在拉伸断裂强度及伸长率、梯形撕裂强力、CBR顶破强力、握持强力及伸长率等力学性能上的差异,为在实际生产以及岩土工程设计中合理选择土工布提供参考。%Mechanical properties of PET spunbond needlepunched geotextiles and PET staple fiber carding needlepunched geotextiles are tested.Also, mechanical difference of these two kinds of geotextiles was studied, including breaking strength and elongation rate at breaking point , trapezoid tearing strength , CBR bursting strength, grab tensile strength and its elongation rate , etc., providing scientific reference for materials production and engineering design .

  9. Dewatering of contaminated reservoir/lake sediment by using geotextile tubes aided by ultrasound%超声辅助絮凝强化污染底泥土工管袋脱水减容

    张景辉; 刘朝辉; 卢丹; 王文茜


    Ultrasonic treatment combined with flocculants was used in dewatering of sediment by geotextile tube. For obtaining low sludge water mass fraction, the effect of the sequence of adding flocculants and ultrasonic on the dewatering performance was discussed. The optimal conditions of ultrasonic treatment were also determined. The results show that adding flocculants firstly and then ultrasonic treatment can achieve better dewatering performance. When the flocculants dosage is 5‰ (dry basis, mass fraction) , the ultrasonic energy density is 0.5 W/mL and treatment time is 10 s, the dehydration effect is the best. Finally, the pilot test of geotextile tube structure was performed. The result indicates that when flocculation mass fraction is 4‰, the dewatering performance of geotextile tube with ultrasound is better than that of the control group without ultrasound, and the curing time of geotextile tubes is shorten. Appropriate ultrasound can decrease the amount of flocculants, reduce costs and shorten the curing time of geotextile tubes, thus improving the efficiency.%将超声处理结合絮凝剂用于土工管袋脱水减容.以滤饼含水质量分数为优化指标,考察超声处理与添加絮凝剂的顺序对脱水性能的影响,并考察了超声处理的最优操作条件.结果表明:先添加絮凝剂再进行超声作用可取得较好的脱水效果,当絮凝剂的投加量(质量分数)为5‰(以干基计),超声波的能量密度为0.5 W/mL,作用时间为10 s,脱水效果最佳.最后进行土工管袋小试,结果表明在质量分数4‰絮凝剂的情况下,施加超声波作用时土工管袋的脱水效果优于未施加超声作用的5‰絮凝剂对照组,土工管袋固化时间缩短.适当的超声作用能减少絮凝剂使用量,降低成本,缩短土工管袋固化时间,提高效率.

  10. HDPE膜与土工布界面摩擦特性的斜板仪试验%Experiment of frictional properties of HDPE geomembrane against and geotextile using tilt table device

    李萍; 唐延东; 李辉山


    斜板仪试验可以为HDPE膜与土工布接触面剪切特性、摩擦性能的研究提供试验参考,也可以为陡峭边坡HDPE膜拉伸与锚固技术提供技术指导.使用不同粗糙程度的HDPE膜、不同干湿状态的土工布进行3种接触面积下的斜板仪试验.试验结果表明:斜板仪试验存在明显的尺寸效应,只有两者接触面积大于200 mm×200 mm,两种材料界面的粘聚力和摩擦角才不会受到接触面积的影响;土工布与HDPE膜接触面的摩擦角和粘聚力一般在潮湿状态下大于干燥状态下;在卫生填埋场运行过程中,垃圾产生的渗沥液对库区边坡土工布的抗滑移是有利的;光面和毛面HDPE膜与潮湿状态下土工布界面间粘聚力差异不明显,但是两种膜的摩擦角却有明显差异.%Experiment with tilt table device could provide a reference for investigation of shear characteristics and frictional parameters of HDPE-geotextile interface, and also provide technical guidance for stretching and anchoring HEPE geomembrane on steep slope. Different roughness of HDPE geomembrane and geotextile with various moisture states were tested with three contact areas on the tilt table device. Test result indicated that there was an obvious size effect during the test. The contact area would not affect the friction angle and cohesion only when the contact area was bigger than 200 mm X 200 mm. The friction angle and cohesion force between wetted geotextile and HDPE geomembrane were generally larger than that between them. In the process of sanitary landfill, the leach produced by the rubbish was helpful for anti-slide and there would be no significant difference in cohesion between smooth HDPE-wet geotextile and rough HDPE-wet geotextile, but their friction angle would be obviously different.

  11. 用图像分析法研究有纺土工织物单向受拉时孔径的变化%Change of pore size of woven geotextiles affected by uniaxial tension using image analysis method

    佘巍; 唐晓武


    现有反滤设计中保土准则使用土工织物未受拉时的等效孔径,但平面单向拉伸会导致该值变化,变大则不满足保土准则,变小则不满足透水准则及淤堵准则。有纺织物孔径由孔径分布曲线和特征孔径反映,采用数字图像分析法对两种有纺土工织物单向受拉时孔径变化进行精确测定。有纺织物被单向张拉至3%,6%,9%和12%的平面应变,随着拉应变的增加,两种有纺土工织物开孔面积率增大;孔径分布曲线向孔径大的方向移动;3种特征孔径值(O30,050和O95)增大,其变化率都与拉应变呈近似线性关系,且小孔径部分相对于大孔径部分随拉伸应变的增长而增大较快。%The equivalent opening size tested under unstrained condition is used in the current retention criterion for design of geotextile filters. However, the equivalent opening size can be influenced by in-plane uniaxial tensile strain. The retention criterion cannot be satisfied when it gets larger, and the permeability criterion and the clogging criterion cannot be satisfied when it gets smaller.The opening size of woven geotextiles can be featured by the pore size distribution and characteristic opening sizes. The opening sizes of two uniaxially stretched woven geotextiles are measured accurately by means of the digital image analysis. The in-plane uuiaxial tensile strains of the woven geotextiles are increased to 3%, 6%, 9% and 12%. The percent open areas of the woven geotextiles and three characteristic opening sizes (i.e., 030, Oso and 095) increase with the increase of the tensile strains. Accordingly, the pore size distributions shift to the direction of the larger open sizes. The change rates of characteristic opening sizes approximately linearly increase with the increase of the tensile strains, and smaller characteristic opening sizes have larger increase with the increase of the tensile strains.

  12. 土工织物散体桩加固粉土路基机理研究%Research on Reinforcement Mechanism of Silt Embankment Using Geotextile Discrete Material Pile

    张京京; 孙立强; 闫澍旺


    Sixu expressway is located in the Huaibei Plain,which is covered by silt or silty sand. However,because this type of soil is prone to liquefaction under seismic loading,liquefaction re-sistance measures should be considered when engineering projects are planned for this region.The liquefaction resistance of a geotextile discrete material pile and the bearing capacity of a composite foundation are examined in this study.In addition,the reinforcement mechanism of the geotextile discrete material pile with a silt subgrade is determined.The pore water pressure dissipation,bear-ing capacity of the composite foundation,pile-soil stress ratio,and pile body stress were re-searched by using the finite difference method and field testing,which is beneficial for obtaining the reinforcement mechanism of the composite foundation.Moreover,this paper presents design proposals of a geotextile discrete material pile.The results indicate that under seismic loading,a geotextile discrete material pile can effectively drain and successfully achieve anti-liquefaction.The excess pore pressure ratio increases with distance from the pile axis,and the silt becomes more in-clined to liquefaction.An engineering example is used with numerical calculation to determine that effective pile spacing is 2 m,or approximately 3.3 times the pile diameter.Further,in the silt foun-dation,the bearing capacity of the single geotextile discrete material pile is 50% larger than that of gravel pile under the same conditions,and the composite foundation bearing capacity of the geo-textile discrete material pile is 25% more than that of gravel pile.In static load testing of the com-posite foundation,soil pressure boxes are respectively buried at the top of the pile,at the bearing plate,and at the contact surface of the pile and soil to determine the bearing capacity of the pile and soil under the action of static load.In the two types of composite foundations,the pile-soil stress ratio increases with an

  13. 生态挡土结构面层与加筋连接强度的试验研究%Experimental study on connection strength between soil bag surface and reinforced geotextile for ecological retaining wall

    蓝日彦; 王保田; 魏军扬; 赵波


    The flexible soil bag reinforced retaining structure has low requirement for the bearing capacity of the foundations. This kind of retaining wall is suitable for foundations and can form green retaining wall or slope. It is a kind of ecological retaining wall which presents harmony between engineering structure and surrounding environment. The connection strength between soil bag face and the geotextile is the key to the stability of the ecological retaining walls. The connection strengths between soil bag face and the geotextile and between filling soil and the geotextile have been obtained by laboratory tests. The results show that the friction angles between soil bag face and the geotextile are 9° ~ 15° for different soils filled into the soil bags, which is much smaller than the friction angle between soil bag faces (above 20°). A new connection style of reverse package has been put forward to overcome the problem of low connection between soil bag face and the geotextile. The friction strength between the soil bag face and the geotextile with the reverse package connection is higher than that between soil bag faces. The reverse package method can overcome the slide failure along the interface of soil bag and geotextile. The test results show that the shear strength (friction strength) between soil bags has significant difference with different filling soils. The friction angle of soil bag face is 20.4° when red clay is filled and 25.5° when gravel is filled.%生态袋加筋柔性挡土结构对地基承载力要求低,具有良好的地基条件适应性,并可以形成绿色挡土墙或边坡,是工程措施与自然和谐共存的一种挡土结构形式.生态袋面层和面层后填土与加筋格栅的连接强度大小,是控制生态挡土结构稳定性的关键.采用室内试验的方法,研究生态袋和填土与加筋格栅的连接强度,结果表明:生态袋与加筋格栅界面摩擦角仅在9°-15°,远小于生态袋间的界面摩擦

  14. Auscultation d'ouvrages avec un capteur géotextile à fibres optiques Earthworks surveillance with a fiber optic sensor-enabled geotextile

    ARTIERES, Olivier ; BRIANÇON, Laurent ; ROBINET, Alain


    Full Text Available Pour évaluer la sécurité d'un ouvrage en terre, il est indispensable de disposer et de pouvoir interpréter des données d'auscultation, mais les mesures sont parfois difficiles à mettre en place et pas toujours fiables sur le long terme. Avec l’insertion de fibres optiques dans un géotextile, la solution TenCate GeoDetect® est le premier système d'auscultation conçu spécifiquement pour les applications géotechniques. Implantée depuis huit ans avec succès sur de nombreux ouvrages, elle permet d’accéder à des informations jusqu’ici très difficiles à obtenir et ceci avec une grande précision.The monitoring solution is based on geotextile and fibre optics composite sensors, to measure both strain and temperature. It is very accurate as the detection thresholds are respectively lower than 0.02 % and 0.1°C, either on localized works or on long linear infrastructures of several tens of kilometres. It is now used for more than 6 years on several walls, embankments on piles or over potential cavities, basins, landfills and dykes.

  15. 尾矿土工织物编织袋层间界面摩擦强度特性研究%Study on the Layer Interface Friction Strength Characteristics of Tailings Geotextiles Woven Bags

    朱君星; 张默; 曹作忠; 李东


    尾矿干式堆存技术近年来逐渐被推广应用,与传统的尾矿库堆存技术相比,尾矿干式堆存能够降低尾矿含水量,增强尾矿的力学性能,提高尾矿库的整体稳定性.在利用土工织物大型编织袋充灌尾矿干堆新技术中,土工织物编制袋层间界面的摩擦强度是影响和决定整个尾矿干堆场稳定性的主要指标.根据制作加工简易的大型土工“似直剪仪”,进行不同含水率和法向压力下的尾矿土工织物编织袋摩擦抗剪强度试验,得出尾矿土工织物编织袋层间界面摩擦系数和抗剪强度关系曲线,同时用一阶线性拟合的摩擦抗剪强度方程较符合摩尔-库伦强度准则.该抗剪强度方程能够反映土工织物层间界面摩擦的物理力学参数及变形特征,为尾矿土工织物编织袋干式堆存筑坝的稳定性计算提供依据.%In recent years,the tailings dry stockpiling technology was gradually popularized and applied.Compared with the traditional tailings stockpiling technology,the dry stockpiling technique can reduce water content in tailings,increase the mechanical parameters of tailings,and improve the overall stability of tailings pond.In the new technology of tailings dry stockpiling with filling of large geotextile woven bag,the interface frictional strength between layers of geotextile woven bag is the main indicator which influences and determines the stability of the entire tailings dry stockpiling.According to the easy production processing of large-scale geotechnical "resembling direct shear apparatus",tailings geotextile woven friction shear strength test under different moisture content and normal pressure is carried out,drawing the relationship curve between interface friction coefficient and shear strength of the tailings layer of geotextile fabric woven bags,simultaneously the linear fitting friction and shear strength equation is in line with the Mohr-Coulomb criterion.The shear strength equation

  16. 土工布加筋土界面摩擦特性试验研究%Experimental research on interface frictional behaviors of the geotextile-reinforced soil

    杨敏; 李宁; 刘新星; 刘乃飞; 苏立海


    Based on the loess filled embankment in Yan'an new airport,and with the geotextile used in engineering practice as reinforcement material,the geotextile synthetic material testing machine jointly developed by Xi'an Yaxing Civil Engineering Instrument adopted to carry out the direct shear tests and pull tests of geotextiles-loess interface so that the direct shear and pull strengths and friction coefficients between geotentile soil interfaces in the case of differ-ent compactness are tested.The test results indicate:①The curves of shear displacement and shear stress is hardening type and the curves of drawing displacement and tensile stress is soften-ing type;②The interface strength of geotextiles-loess conforms with the Mohr-Coulomb strength theory.The friction behaviors of the geotextile-loess interface is very good.But the friction coef-ficient of direct shear is greater than that of pull test in the same condition;③In the shearing conditions,the interface strength of geotextiles-loess is not sensitive to the compaction degree, but in the drawing conditions,the compaction degree has a significant effect on interfacial cohe-sive force.%以延安新机场黄土高填方为依托,以工程实际使用的土工布作为筋材,采用与西安亚星土木仪器有限公司共同研制的土工合成材料试验机,进行了黄土加筋土的直剪试验和拉拔试验,测试了不同压实度条件下筋土界面间的直剪和拉拔强度以及摩擦系数.试验结果表明:①剪切位移与剪应力关系曲线为硬化型,而拉拔位移与拉应力关系曲线为软化型;②土工布与黄土的界面强度在直剪和拉拔条件下均符合莫尔库仑强度理论,土工布与黄土间具有较好的摩擦特性,但相同条件下直剪摩擦系数大于拉拔摩擦系数;③剪切条件下筋土界面强度参数对压实度不敏感,而拉拔条件下压实度对界面粘聚力影响显著.

  17. Experimental study on dewatering and consolidation of sludge from environment dredging by using geotextile tubes%土工管袋用于环保疏浚淤泥脱水固结的试验研究

    王琦; 仰建国; 范文雪


    The dewatering and consolidation experiment of sludge from environmental is carried out by using small-sized geo-textile tubes. The influences of different structural characteristics of geotextile tubes such as weaving method,weaving structure and aperture,and dosages of dewatering agent on its dewatering and consolidation effects are studied. The results show that the dewatering and consolidation effect of the woven twill geotextile tube with 0.5 mm aperture is better. And the effect of cationic polyacrylamide (CPAM) in the dosage of 0.6~1.0 g/kg is also better. But the best dosage must be adjusted according to the different conditions in the practical projects.%利用小型土工管袋进行环保疏浚淤泥脱水固结试验,研究土工管袋的不同结构特征(织造方式、织造结构、等效孔径)和脱水药剂用量对环保疏浚淤泥脱水固结的影响。试验结果表明:脱水药剂阳离子聚丙烯酰胺(CPAM)在0.6~1.0 g/kg投加量下配合0.5 mm等效孔径机织斜纹土工管袋组合,在疏浚淤泥脱水固结方面表现较好,但脱水药剂具体最佳用量需在实际工程中根据不同工况做适当调整。

  18. Dewatering and Volume Reduction of Heavy Metal-contaminated Sediments in Lake and Reservoir Using Geotextile Tubes%重金属污染底泥的土工管袋高效脱水减容研究

    张景辉; 刘朝辉; 西伟力; 王旭东; 董晶; 毕涛; 王文茜


    基于环保疏浚过程中湖库重金属污染底泥的特点,研究了土工管袋处理技术脱水减容重金属污泥的效果.通过试验筛选和优化,获得了土工管袋脱水效果最佳的重金属螯合钝化调质剂ECO-DEMETAL及其最佳添加量.通过容量为25 L的小袋脱水试验研究发现,脱水7d后污泥含固率由5%提高到70%左右,污泥脱水后重金属浸出毒性的检测结果远优于《生活垃圾填埋场污染控制标准》( GB 16889-2008)的指标要求.通过土工管袋1:1现场扩大试验,获得了容量为1 000 m3的大型土工管袋污泥脱水工程应用经验,脱水效果非常理想,含固率>50%,重金属钝化效果也完全满足填埋造岛资源化处置的环保要求.%Based on characters of heavy metal-contaminated sediments in lake and reservoir during environment-friendly dredging, the dewatering and volume reduction of heavy metal-contaminated sediments with geotextile tubes were studied. A conditioner, known as ECO-DEMETAL for heavy metal che-lation and passivation with the optimal dewatering efficiency of geotextile tubes as well as its optimal dosage were obtained by selection and optimization experiments. The dewatering result of 25 L geotextile tube show that the solid content of sludge is increased from 5% to 70% within 7 days, and the toxicity characteristic leaching procedure ( TCLP) result meets to the requirement of the Standard for Pollution Control on the Landfill Site for Domestic Waste ( GB 16889 -2008). Dewatering experiments in pilot scale were carried out for verification of dewatering performance of 1 000 m geotextile tube. The pilot results show that the dewatering efficiency is ideal, the solid content of sludge is more than 50% , and the passivation effect of heavy metals also meets the environmental requirement in landfdl resource disposal for island creation.

  19. Experimental study of deformations of reinforced cushion by high-strength woven geotextile in closing levee%圈围工程中高强有纺土工布加筋垫层变形试验研究

    曹国福; 徐兵; 王茂胜; 姚顺雨; 刘丽; 刘益锋


    应用大刚度、长标距、大量程的 SDW-100型位移传感器,采用500 kN/m 高强有纺土工布进行室内试验和现场试验,研究高强土工布加筋垫层的变形情况。室内拉伸试验成果表明,位移传感器在每级加荷情形下的变形量与试验机上显示变形量具有较好的一致性,说明该类型传感器用于现场加筋高强土工布的变形测试是适用的,并因此得到高强有纺土工布的变形模量为8314.4 kN/m。现场试验表明,(1)大堤底部的土工布位移曲线基本表现为盆形,中轴线下的土工布位移量最大;(2)大堤下部土工布的位移量大小与外棱体的位移方向明显相关;(3)现场试验中高强土工布的最大实测变形率为11.9%,按室内试验得到的变形模量计算出该计算高强有纺土工布的应力值为837.40 kN/m,表明按照现场实际加荷速率设计的高强有纺土工布强度值偏小;(4)施工间歇期高强土工布的应力会出现重分布现象,具体表现为大堤轴线下变形量明显减小,现场实测成果与 Plaxis 有限元计算成果规律性吻合情况较好,试验成果符合一般规律;(5)土工布的变形率与围堤上部现场施工加荷的速率关系很大,现场施工时设计单位应当提出一个加荷速率控制值;(6)当高强有纺土工布的强度一定时,土工布的伸长率相对较大有利于快速加荷施工。%By using the data acquired from laboratory and field monitoring program, this study assessed the displacements of high-strength geotextile used as basal reinforcement of a closing levee. The displacements of the geotextile were monitored by high stiffness, large gauge length and measuring range SDW-100 displacement transducers with 500 kN/m high-strength woven geotextile .The transducers were first calibrated in a multi-function test machine. The tensile test of the geotextile yielded a tensile stiffness of 8314.4 kN/m. The field

  20. 土工织物加筋法加固软基边坡的效果分析%Analysis of the Consequence of Soft Ground Slope Reinforced by Geotextile-reinforced Method

    王由国; 李守德; 仲曼


    In this paper,a generalized model of the typical cross-section was used to study the consequence of soft ground slope with different depth which wsa reinforced by Geotextile-reinforced method vsing PLAXIS software. The comparisons of the overall safety factor,vertical displacement and horizontal displacement were analyzed. The result shows that the geotextile-reinforced method can significantly enhance the overall stability of the slope,and reduce the uneven settlement and lateral deformation. When the soft ground is relatively thin,the laying of geotextile can greatly improve the overall stability of the slope,but the reduction of deformation is not obvious;for the thicker soft ground,the effect is opposite. Moreover,the improvement of overall stability of the slope by laying multi-layer Geotextile is not obvious.%通过构造软基边坡概化模型,利用有限元软件PLAXIS分析土工织物在不同软基深度下边坡中的加固效果,主要将整体安全系数、竖向位移与水平位移进行对比分析,分析结果表明土工织物加筋法,可明显提高边坡的整体稳定性、减小地基的不均匀沉降和限制侧向变形。当软基厚度较薄时,土工布的铺设可大大提高边坡的整体稳定性,但是位移的减小程度不明显;对于软基厚度较大,加固效果与软基厚度较薄时恰好相反;而且,多层土工织物的铺设对于边坡稳定性的提高并不明显。

  1. 长丝机织土工布砌体结构加固静载试验研究%Test Study on the Masonry Structure Reinforced by Filament Woven Geotextile Unde r Static Load

    郑人逢; 孙青; 律清; 宫必宁


    It is estimated that the next 10 to 30 years in the future will be the peak of reinforcement and reconstruction in China ,and the masonry structure will still play a significant role in people’s everyday life and production for a very long time ,Therefore the reinforcement and reconstruction of masonry structure are necessary at present . In order to seek a main strengthening material with the advantages such as excellent strengthening effect and low economic cost ,the filament woven geotextile was selected as research object through investigation and screening .According to the research and analy-sis of axial-compressing and shear strength for the masonry component with different geotextile reinforcement ratio and method ,as well as the comparison of carbon fiber reinforced masonry structures with the same condition ,it was concluded that two kinds of reinforcement materials for masonry structure have certain comparability .During the test ,the bearing capacity of masonry specimens reinforced by filament woven geotextile improved obviously ,and the specimens still had certain ductility when reaching the ultimate load .Besides ,the filament woven geotextile has a good economic advantage as main strengthening material .%为了寻求一种加固效果好、经济成本低的加固主材,通过调研和初步筛选,拟选取长丝机织土工布作为试验研究对象。通过对砌体构件土工布不同加固率、加固方式下轴心抗压、顺缝抗剪等试验研究分析,并与同等条件下碳纤维布加固砌体构件的加固效果对比,得出两种加固材料的砌体结构加固效果具有一定的可比性。长丝机织土工布加固的砌体试件承载力显著提高,而且达到极限荷载后还表现出一定的延性,同时长丝机织土工布作为加固主材,有很好的经济优势。

  2. Research on Mechanism of Geomembrane/Geotextile Interface Strength%土工膜/无纺土工织物界面强度形成机理研究

    李砚; 宋晓光; 栾金龙


    In order to study the effect of the interface contact status on the geomembrane/geotextile interface strength in landfill site ,and taking the interface contact status as the only variable ,the direct shear tests were carried out by exclud-ing the effects of other factors so as to obtain the changes of the geomembrane/geotextile interface contact status with nor-mal stress .Through comparing with the results of preloading direct-shear test and normal shear test ,the effects of the changes of the geomembrane/geotextile interface contact status on the interface strength were identified .It is found that the wrapping fiber ratio and wrapping fiber density are the major influencing factors on the interface strength peak ,and based on this ,the connection formula between the increment of the interface strength peak before and after preloading and the wrapping fiber ratio together with the wrapping fiber density is established .The research results show that with the constant normal stress ,the changes of the geomembrane/geotextile interface contact status could result in the changes of the interface streugth peak .%为研究填埋场衬垫系统中土工膜/无纺土工织物界面强度受界面接触状态的影响,将界面接触状态作为单一变量进行直剪试验,排除法向应力等其他因素对界面强度的影响,得到土工膜/无纺土工织物界面接触状态随法向应力的变化。通过对预压直剪试验和常规直剪试验结果的比较找出土工膜/无纺土工织物界面接触状态的变化对界面强度的影响。发现界面接触状态中裹覆纤维比和裹覆纤维密度这两个参数是影响界面峰值强度的主要因素,并建立界面峰值强度预压前后的增量与裹覆纤维比和裹覆纤维密度的关系式。即使法向应力不变,土工膜/无纺土工织物界面接触状态改变也能使界面峰值强度发生变化。

  3. 重载铁路盐渍土路基中土工布使用寿命评估%Life Prediction for Geotextile in Saline Soil Roadbed of Heavy Haul Railway



    研究目的:欲使土工布大规模地应用于工程,对其寿命的影响需进一步研究。针对土工布多为出厂预期寿命,缺乏工程最关心的现场使用寿命判定依据,且国内、外研究成果不多,本文通过现场和室内研究,以期确定其使用寿命并获得土工布保护技术,为重载铁路路基中土工布使用设计与施工提供参考。研究结论:(1)结合现场埋置土工布跟踪分析,初步估计盐渍土路基中两布一膜土工布现场使用寿命在80年以内;(2)两布一膜土工布的老化因素影响程度由大到小依次为紫外线、高拉应力、盐池水、海水等;(3)基于现场取样试验和运营线路调查分析,建议工程抽检周期为10年;(4)该研究成果可为盐渍土铁路、公路和民航工程的设计与施工提供依据。%Research purposes:For lack of the research results of geotextile field life at home and abroad,in this paper, the lab and field researches are carried out to find the engineering life and protect technology in field.which will provide reference for the design and construction of geotextile in heavy haul railway roadbed. Research conclusions:(1 )A preliminary estimated life of two cloth a membrane geotextile in saline soil embankment is within 80 years by tracking experiments.(2)The effect sequences of aging factor of two cloth a membrane geotextile are as follows:ultraviolet,high pressure,salt pond water,sea water,etc.(3)The engineering sampling period is suggest as 1 0 years based on field sampling test and operating line survey.(4)The research results can be successly used in some saline soil railway,highway and civil aviation engineering.

  4. Mechanical Mechanism Analysis of Geotextile Tubes Applied in Offshore Low-Crested Breakwaters%离岸浅堤中土工织物充填管状袋的力学机理分析

    张文斌; 谭家华


    In existed researches, the mechanical mechanism analysis of geotextile tubes applied in this complicated new type of breakwaters was never considered. Based on the investigation of the mechanical properties of geotextile tubes,in this paper the stability and transmission behaviors of offshore low-crested breakwaters are studied.And the cross section shape and circumferential tension of geotextile tubes are obtained by the method of elliptic integrals.The numerical example results show that the geotextile tubes as the cores are reliable and the methods presented in this paper can be used efficiently in the design process of complicated new type breakwaters.%与传统的离岸堤相比,土工织物充填管状袋作为堤心构成的新型离岸潜堤形式不仅具有减小波浪力的作用,还具有经济和美观的功能.然而,在现有的研究中还没有对这一复杂新型式的防波堤中的土工织物充填管状袋的力学机理分析的考虑.本文在土工织物充填管状袋的力学性能研究的基础上,对离岸浅堤的稳定性和透射性能进行了研究.土工织物充填管状袋的横截面形状和周向拉力采用椭圆积分方法得到.计算实例结果表明:土工织物充填管状袋作为堤心是可靠的,同时,文中提出的研究方法可在复杂新型离岸浅堤的设计过程中发挥积极作用.

  5. 宁夏银北排水项目暗管排水外包滤料试验研究%An Experimental Study on Geotextiles used as Sub-drain Pipe Filters in Yinbei Drainage Project in Ningxia

    丁昆仑; 余玲; 董锋; 周华; 张新华


    The permeability of 12 types of geotextiles, used as sub-drain pipe filters, were tested andcompared under two kinds of soils sampled from Ningxia Yinbei Drainage Project area. The prelimi-narily selected geotextiles, based on the test results, will be further tested and evaluated in fields andthese experimental data will be important reference for selection of proper filters for Yinbei DrainageProject area.%采用一维和二维渗透模型对土工织物作为农田暗管排水外包滤料进行了试验研究。试验用的2种土壤取自宁夏银北暗管排水区,对12种不同土工织物的透水效果进行了测定和对比分析,其初选结果将用于野外现场作进一步观测评价,并最终为宁夏银北暗管排水滤料选择提供依据。

  6. 土工织物淤堵程度的量化方法探讨%A study on Permeability Forcast of Needle Punched Non-woovonb for Geotextile Use

    周蓉; 刘逸新


    The permeability coefficient of geotextiles was calculated based on 24 hours continul clogging test of different needle punched fabric samples. According to the obtained data, the thesis studied choke level and forcost permeability by using Time-Alignment analysis method. The result showed that it would provide an exact and reliable designing basis for the geotextiles in engineering pracilce%通过对不同规格针刺土工织物连续24小时的反复实验,计算土工织物渗透性能的变化,根据数据与时间密切相关性采用时间序列分析方法,进行土工织布淤堵程度的量化分析和渗透性能的预测,从而为土工织物的工程应用提供准确可靠的设计依据。

  7. 土工布拉伸强度的测定及其不确定度评定%A Tensile Strength Test of Geotextile on MTS and Evaluation on the Measurement Uncertainty

    于书凤; 王时越; 刘国寿; 缪云伟


    The tensile strength test of two teams of geotextiles ( each 10) are made with self-made clamp which meets the slanderer requirement on MTS 810( nonspecial-purpose test machine). Examining how the data which get from experiment distribute and determining abnormal data, then calculation of tensile strength and evaluation on measurement are finished with valid data. The result shows tensile strength test of geotextile can finish on MTS and measurement repeatability is to introduce the most important factors of uncertainty.%以两组(各10块)某一规格的土工布为研究对象,按相应规范要求,采用自制夹具,在MTS810试验机(非专用试验机)上完成试验.针对两组试验数据进行分布检验,对异常数据进行判断并对其拉伸强度进行了不确定度评定.结果表明,用MTS试验机对土工布进行拉伸强度试验是可行的,测量的重复性是引入不确定度的最主要影响因素.

  8. 土工布加筋垫层对路基变形和稳定的影响%Effect of the geotextile-reinforced sand cushion on the deformation and stability of the foundation under a embankment

    翁升; 马时冬


    某高速公路高填方路堤下的深厚软基,采用以塑料板排水为主,配合机织土工布加筋砂垫层进行了软基处理.在对有加筋砂垫层和无加筋砂垫层的软基变形性状进行比较的基础上,评价了加筋砂垫层的作用及效果.还通过计算,分析了机织土工布的预应变对路基稳定性的影响,从而说明施工加筋砂垫层时,对加筋材料施加预应变的重要性.% The soft foundation under a freeway compacted by high fill was treated mainly by drainage with plastic plates cooperated by woven geotextile-reinforced sand cushion. Based on the comparison of the deformation behavior of soft foundation of both reinforced sand cushion and ordinary sand cushion,the role and effect of the reinforced sand cushion were evaluated. At last,the effect of the prestrained geotextiles on the stability of the embankment was analyzed through calculation,thus the importance was shown of the prestrain in construction.

  9. 双向不等轴拉应变对有纺织物开孔面积率的影响%Effect of unsymmetrically biaxial tension on percent open area of geotextiles

    赵文芳; 唐晓武; 白彬


    Geotextiles are widely used in people's living and project construction, mainly for water proof, filtration, heat preservation, isolation and many other aspects. The percent open area is one of the most important parameters which reflect the performance of geotextiles. The change laws of the percent open area in unsymmetrically biaxial tension tests are explored through the imagine analysis, and the results are more applicable than those of the uniaxial tension tests and symmetrically biaxial tension tests by the previous researchers. The difference between the theoretical and experimental values is compared, and the idea of“Projective Poissons ratio” is proposed.%土工织物应用于防水、反滤、保温、隔离等方面,土工织物的开孔面积率是反映土工织物性能的重要参数,前人对此已有研究,主要集中在单轴拉伸和等双轴拉伸试验。通过双向不等轴拉伸试验,运用白彬推导的公式,采用图像法测试土工织物在双向拉应变下的开孔面积率POA(Percent Open Area)的变化,分析理论值与试验值之间的偏差并加以修正,提出“投影泊松比”的概念,同时探究投影泊松比对开孔面积率的影响。

  10. Application of bamboo net and geotextile in shallow surface treatment of soft ground%竹网+土工织物在软土地基浅表层处理中的应用

    向继华; 曹琰; 祁先涛


    The bamboo net and geotextile technology takes the bamboo as the main construction material to deal with the surface of soft ground.Binding the bamboo net with geotextiles and other geosynthetics to form a reinforced semi-steel body,the upper surface of which is covered with the sand layer or soil cushion with a certain thickness to enhance the bearing capacity of the soft ground base and meet the requirements of the operation surface for the light & medium sized equipment construction.In the WE3 road surface soft foundation treatment of the eastern part of the economic zone and municipal infrastructure construction projects of Shantou city,according to the thickness of the silt layer,we adopt the bamboo net treatment technology,and quicken the construction progress and save the construction cost.%竹网+土工织物是一种以原生竹材为主要施工材料处理松软地基表层的工艺。该工艺一般为绑扎竹网配以土工布等土工合成材料,形成加筋半刚性体,上覆一定厚度的砂或土垫层以增强软土地基表层承载力,满足作业面轻型、中型设备施工条件的要求。在汕头市东部经济带市政基础设施建设项目WE3路浅表软基处理施工中,结合现场淤泥层厚度采用了竹网浅表软基处理工艺,有效地提高了施工进度,节约了施工成本。

  11. Interface shear strength of textured geomembrane with nonwoven geotextile and change pattern of surface asperity%糙面土工膜与无纺土工织物界面剪切强度及表面粗糙度变化规律

    施建勇; 李砚


    为了量化糙面土工膜表面粗糙度变化规律,研制了表面粗糙度测量仪,并进行了不同法向应力下糙面土工膜和无纺土工织物界面剪切和对应的糙面土工膜表面粗糙度试验。研究表明,糙面土工膜和无纺土工织物界面剪切强度是由糙面土工膜粗糙凸起和无纺土工织物纤维相互嵌入和拉拽作用产生的,界面的剪切峰值摩擦系数主要受到法向应力的影响,界面强度发展到残余强度,糙面土工膜粗糙凸起磨损趋于稳定,无纺土工织物纤维定向排列完成。%In order to quantitatively investigate the pattern of change of the surface asperity of textured geomembrane, a new apparatus for measuring surface asperity was developed. Interface shear tests of textured geomembrane with nonwoven geotextile under different normal stresses and corresponding tests on the surface asperity of textured geomembrane were conducted. The results show that the interface shear strength of textured geomembrane with nonwoven geotextile is caused by the embedding and pulling actions between textured points of geomembrane and geotextile fabric. The peak interface shear friction coefficient is mainly influenced by normal stress. When the interface shear strength tends to be residual strength, the damage to textured points of geomembrane tends to be stable and the fabric orientation of geotextile is fully achieved.

  12. 土工布在水泥混凝土路面加铺沥青混凝土层结构中的抗剪试验分析%Analysis of Shear-Bearing Test for Geotextile Between Cement Concrete and Asphalt Concrete Overlay

    侯荣国; 牛开民; 田波


    在水泥混凝土路面加铺沥青混凝土面层(简称“白加黑”)的路面结构中,利用层间铺设土工布来延缓、减少反射裂缝是一种经常被采用的技术方案.但铺设土工布后,层间黏结力下降,容易造成沥青混凝土加铺层推移而致过早破坏.针对此现象,运用有关力学软件计算分析了水泥混凝土面板与沥青混凝土加铺层结构中的层间剪应力,发现层间光滑时的剪应力大于层间黏结时的剪应力;同时,通过试验路与室内试验,分析了铺有土工布的水泥混凝土面板与沥青混凝土层之间的抗剪能力,发现土工布满足层间抗剪要求,但抗剪富余系数不大,因此铺有土工布的水泥混凝土路面加铺沥青混凝土层的路面结构容易发生推移破坏.%To prevent reflective cracking, the geotextile is often layed between cement concrete pavement and asphalt concrete overlay. But cohesion between two layers is reduced after construction of geotextile, so it creates moving of asphalt concrete overlay. The shear stress between old cement concrete pavement and asphalt concrete overlay is analyzed through finite element model. It is found that shear stress is bigger on the assumption of perfectly smooth compared to the assumption of perfectly junction.Through experiment road and indoor test, shear-bearing capacity between cement concrete pavement and asphalt concrete overlay is analyzed while the geotextile is layed. It is found that the geotextile can satisfy the request for single shear-bearing, but redundancy coefficient is low, so moving of asphalt overlay is created easily when the geotextile is layed between old cement concrete pavement and asphalt concrete overlay.

  13. Function Control of Rice Straw Geotextiles Mulch on Upland Red Soil Erosion and Nutrient Loss%稻草编织物覆盖对坡耕地红壤土壤侵蚀和养分流失的控制作用

    邢向欣; 郑毅; 汤利


    Filed trails were carried out to study the effects of rice straw geotextiles mulch on upland red soil erosion control and corn growth. The results showed that, rice straw geotextiles were increased maize yield and effective control soil erosion and nutrient loss on upland red soil. The total runoff and soil sediment of rice straw geotextiles mulch were decreased by 38.40% and 75.36% comparing with no mulching and were decreased by 15.41% and 5.83% comparing with the ploythene film mulch. The organic matter, total nitrogen, total phosphorus and total potassium of erosion soil loss of rice straw geotextiles mulch were occupied by 12.04%, 12.15%, 12.11% and 12.48% separately with no mulching. The organic matter, total nitrogen, total phosphorus and total potassium of erosion soil loss of the ploythene film mulch were occupied by 48.66%, 52.55%, 54.54% and 53.37% separately with no mulching. Effect function control of soil runoff, sediment and nutrient loss on upland red soil were: rice straw geotextiles mulch 〉 polythene film mulch 〉 no mulching. Functions of soil erosion control of rice straw geotextiles mulch were more remarkable difference during rainoff collect period. The maize yields of rice straw geotextiles mulch and ploythene film mulch were increased by 8.05% and 29.67% comparing with that of no mulching treatment%采用田间小区试验,研究了稻草编织物覆盖在坡耕地红壤水土流失控制上的作用及其对玉米生长的影响。结果表明:在坡耕地红壤上,稻草编织物覆盖能有效抑制土壤侵蚀和养分流失,增加玉米产量。在种植玉米条件下,稻草编织物覆盖比无覆盖处理土壤的径流量和侵蚀量分别降低了38.40%和75.36%,比薄膜覆盖处理土壤的径流量和侵蚀量分别降低了15.41%和5.83%。稻草编织物覆盖侵蚀土壤流失的有机质、全氮、全磷和全钾分别占无覆盖处理流失量的12.04%,12.15%,12.11%和12.48

  14. Mechanical Response of Geotextile Bag with Sand Cofferdam under Pumping Disturbance of Zhoutouzui Immersed Tunnel%洲头咀沉管隧道干坞抽水扰动下模袋砂围堰力学响应研究

    杨春山; 魏立新; 莫海鸿; 陈俊生; 刘力英


    The detailed model for dry-dock pumping process was established based on Zhoutouzui immersed tun-nel in Guangzhou to investigate mechanical response of geotextile bag with sand cofferdam. The performance of wa-terstop wall combined of steel sheet pile and bagged clay was evaluated and the deformation of geotextile bag with sand cofferdam was explored as well as the tension of geotextile bag was calculated, which simplified calculation method was proposed. The results show that the effect of combined waterstop wall is excellent. The influence of dry-dock pumping on cofferdam deformation is significant, which is a homodromous linear relation. The density of cof-ferdam increase caused by dewatering, which increases overlying pressure from upper geotextile bag to lower one and makes geotextile vertical flattening deformation. And then flattening deformation and seepage caused by head difference make cofferdam horizontal displacement. The tension of geotextile bag increases with water level decrease in a nearly linear relation and comparing with numerical calculation results indicate that simplified calculation meth-od of tension is reasonable.%为深入研究模袋砂围堰对沉管隧道干坞抽水力学响应规律,以广州洲头咀沉管隧道模袋砂围堰工程为背景,建立干坞抽水全过程精细数值模型。计算验证了钢板桩+袋装黏土组合芯墙止水性能。分析了干坞抽水引起的模袋砂围堰变形规律。并揭示了围堰土工模袋张力分布规律,此外提出模袋张力简化计算方法。研究表明:模袋砂围堰钢板桩+袋装黏土组合防渗芯墙止水效果良好,能有效控制临江侧水流渗入干坞侧;干坞侧抽水对模袋砂围堰变形产生了显著的影响,变形与坞内下降水位近似呈同向线性关系;坞内水位降低使围堰重度由浮重度变为干重度,引起模袋砂压实而出现较大竖向位移;围堰竖向压缩和水头差引起的渗流作用又

  15. Study on Influence of Geotextile and Its Laying Position to Anti-Cracking Performance of Asphalt Mixture%土工材料及其加铺位置对沥青混合料抗裂性能影响研究

    莫石秀; 孔令云


    By comparing bending test, cracking test, uniaxial compression test, and fatigue test on sample beams of fiber glass geo - grid, paving polyester filament singeing Geotextile and geo - grid with no paving, this paper studies influence to performance of asphalt mixture by different geotextile material and its laying position. Analysis on test results shows that laying fiber glass geo-grid has obvious influence to rupture strain of asphalt mixture which has greatly improved the stiffness modulus as well as the anti -fatigue performance. As temperature reduces, test samples paved with fiber glass geo-grid has better anti-tensile strength comparing with test sample paved with geo-textile cloths. However, the influence on rupture strain or stiffness modulus was not so obvious.%通过比较玻璃纤维土工格栅、加铺聚酯长丝烧毛土工布以及不加铺土工格栅的试样小梁弯曲试验、劈裂试验、单轴压缩试验、疲劳试验,研究不同种类土工材料及其铺设位置对沥青混合料性能的影响。试验分析表明:铺设玻璃纤维格栅对沥青混合料破坏应变影响显著,对其劲度模量有较大改善,且其疲劳性能也得到明显改善;随着温度降低,加铺玻璃纤维格栅后试件抗拉强度提高幅度明显高于加铺土工布的,但对其破坏应变、劲度模量的影响不是很显著。

  16. Field model tests on effective dewateringtechnology of geotextile tube filled by soil with high clay (silt) particle content%高含黏(粉)粒土料充填管袋高效脱水工艺现场模型试验

    吴海民; 束一鸣; 常广品; 刘云锋; 刘欣欣; 顾克


    针对高含黏(粉)粒土料充填管袋脱水固结速率慢,无法满足一天一层管袋施工要求的问题,通过现场大型充填管袋脱水模型试验来验证前期室内试验研究提出的放水排泥、充排结合的快速脱水施工方法。通过现场实时监测管袋充填施工及脱水过程中不同部位土体的孔隙水压力、固结度、含水率、级配和干密度等指标的变化情况,对比分析了不同施工方法的优劣,验证了室内试验提出的高含黏(粉)粒土料充填管袋坝高效脱水施工工艺的可行性和实际效果。%The dewatering velocity of geotextile tubes filled by soil with high clay (silt) particle content is very slow. That cannot meet the requirements of construction speed that a layer of geotextile tubes must be completely filled and preliminary solidified within one day. Several large-scale field model tests are conducted to verify the previously proposed construction methods, which combines actively discharging muddy water with the alternately filling and discharging methods. The indexes including pore water pressure, consolidation degree, water content, particle gradation and dry density of the filled soil in different positions within the geotextile tubes are real-time monitored during the whole filling and discharging process. Through the monitoring data, the comprehensive dewatering velocities of different construction methods are comparatively analyzed. The results have verified the feasibility and actual effect of the proposed dewatering method for high clay (silt) particle-content soil-filled geotextile tubes.

  17. Implementación de ‘Escuela de espalda’ mediante la técnica de ‘Core’ en una fábrica de geotextiles para la prevención del dolor lumbar

    Claudia Lucia Vélez


    Full Text Available Introduction: This article aims to show an alternative intervention for the prevention and control of back pain to the people of a production plant of geotextiles for the construction exposed to handling and awkward postures through the implementation of the Back School using the CORE technique. This technique being understood astrainer of the stability musculature of the spine; whose benefitis proportionate the muscular complex of the back, stability andavoid osteomuscular lesions and improved posture. Objective: To present the results about the implementation of the back school by the CORE technique for prevention of back pain in a population offorty-eight male collaborators. Materials and methods: The backschool began with talks of awareness by the occupational health physician explaining the objectives and benefits of it to allparticipants. Once this activity was done, was continued to evaluateall plant employees to establish health status through the PAR-Qquestionnaire, who were surveyed for the perception of pain usingvisual analog scale (VAS and stability was determined column throughthe CORE assessment, to determine the training plan. Then, were made every six months the revaluations and implementation of a survey of assistant public perception to identify the impact of the implementation of the school back on the two variables referred (pain perception and stability of column. Results: The pain perceptionaccording VAS increased in the number of workers asymptomatic in 12% and based in the satisfaction survey 94% of population reported thatwith the development of this technique decrease the muscle fatiguein lumbar level; and 96% of population reported an improvement in theperformance of their work activities. Discussion: Posterior to theanalysis of all results, it is interpreted that back schoolspractice through CORE technique, contributes to the prevention and /or control of symptoms at the lumbar level in population of productive

  18. Pullout Behavior of Geotextiles: Numerical Prediction

    Sieira, A. C. C. F


    Full Text Available The mechanism of soil-geosynthetic interaction is usually complex and depends on the nature of the reinforcement, as well as on the characteristics of the surrounding soil. The strength parameters of the interface are the key for the design of reinforced soil slopes. Usually, these parameters are defined from laboratory pullout tests. The absence of test results implies on conservative assumptions and higher costs. The possibility of using computer programs for analyzing the load transfer mechanism arises as an attractive design tool. This paper presents the numerical simulation of pullout tests, conducted in large equipments. The numerical predictions of the load and displacement distribution along the geosynthetic length were compared to instrumented test results, available in the literature. The analyses revealed to be satisfactory and consistent with the experimental results. Thus, it becomes possible to reduce the uncertainties in the design of the anchorage length for the reinforcement by previously performing studies with computer programs that simulates stress x strain behavior of geotechnical problems

  19. Uso de geomantas no controle da erosão superficial hídrica em um talude em corte de estrada Evaluation of geotextiles to control surface runoff on a roadside

    Leonardo Silva Fernandes


    available erosion control means. The study objective was to evaluate the efficiency of three commercial erosion mats: MacMat®, Fibrax® and Tela Biotêxtil® in rainfall surface erosion protection. The experiment was carried out between December 2003 and March 2004 on an embankment of a road section in Viçosa, Minas Gerais State, Brazil. Surface runoff from the experimental area was analyzed based on eight rainfall events and data of the following variables: solid mass and volume of suspended soil + water runoff. These data were compared in relation to geotextiles with or without vegetation (a mixture of grass and legume species. The treatments were: Treatment 1 - Control (exposed soil; Treatment 2 - Tela Biotêxtil® with plants; Treatment 3 - MacMat® without plants; Treatment 4 - MacMat® with plants; Treatment 5 - Fibrax® without plants and Treatment 6 - Fibrax® with plants. The Tukey test was used at 5% for the statistical analysis. Although no significant differences were found among treatments due to the high variation coefficient, it was obvious that erosion mats generally reduce soil loss. Treatment 6 was the most efficient. The volume of suspended soil + water runoff was however highest in Treatment 5 (mat without plants. The erosion mats enhanced soil protection against surface erosion by rainwater; vegetation planting along with the mats improved results for all treatments.

  20. The applications of geotextiles in the sanitary landfills; Aplicaciones de los geotextiles en los vertederos

    Morera, J.; Marin, J.


    The spillways controlled of Solid Urban Residuals, Industrial Residuals and Industrial Special Residuals should be waterproofed. The waterproofing should be assured, to avoid the possibility of contamination of the aquifer for the filtration of leachates coming from the garbage and rain waters eventually polluted for their contact with the mass of deposited waste already.


    The liquids management strategy for any municipal or hazardous waste landfill requires a knowledgeable design strategy for the leachate collection system located at the base of the waste mass. Such leachate collection systems generally consist of sumps, perforated pipes, drainag...

  2. Application of sand and geotextile envelope in subsurface drip ...



    Aug 9, 2010 ... Subsurface drip irrigation is a technology used for better management of irrigation water. This ... for commercial vegetable production, with turbulent flow ... delivery system to carry the water to the field (Reich et al., 2009).

  3. Water flow through the polypropylene-based geotextiles.

    Patanaik, A


    Full Text Available velocity data obtained from water permeability test and theo- retical prediction based on FEA. References 1. Mao, N.; Russell, S. J. J Textile Inst 2000, 91, 235. 2. Mao, N.; Russell, S. J. J Textile Inst 2000, 91, 244. 3. Sullivan, R. R.; Hertel, K.... 7. Patnaik, A.; Rengasamy, R. S.; Kothari, V. K.; Ghosh, A. Wet- ting and Wicking in Fibrous Materials; Textile Progress; Wood- head Publishing: Cambridge, UK, 2006. 8. Mao, N.; Russell, S. J.; Pourdeyhimi, B. In Russell, S. J., Eds.; Woodhead...

  4. 土工织物耐久性及影响因素分析%Analysis of Durability of Geotextile and Factors Affecting Durability of Geotextile

    张敬; 叶国良



  5. Laboratory Investigation of the Use of Geotextiles to Mitigate Frost Heave


    were conducted, so it is not known T-100 -22.4* if the fabric was part of the capillary break. Typar 3401 82.8 33 Roth’s experiments revealed that the...sample ML through 12 small holes, about 0.8 mm (0.03 in.) 13 o Mar otte Tube Water Supply iconstant head) ir Pressure 3Way Valve Tensometers was saved and the other half was divided into six matic scans of the data began. Scans could also be equal parts for water content determinations

  6. Evaluation of Geotextile Reinforced Embankments on the Farmer’s Loop Road in Fairbanks, Alaska


    Is 10.000 4.000 0 0 0 IS 20.000 4.000 0 0 0 17 20000 4 000... iTIL ...10.00: 7.000 0 0 28 20000 T 0 0 !.b . 16*o6 Y. . .:o66 ........ .......b ........ .. ..................... . 21 26.000 7.000 0 0 0 22 42.000 7.000 0 0

  7. Distributed strain measurement with polymer optical fibers integrated into multifunctional geotextiles

    Liehr, Sascha; Lenke, Philipp; Krebber, Katerina; Seeger, Monika; Thiele, Elke; Metschies, Heike; Gebreselassie, Berhane; Münich, Johannes Christian; Stempniewski, Lothar


    Fiber optic sensors based on polymer optical fibers (POF) have the advantage of being very elastic and robust at the same time. Unlike silica fibers, standard PMMA POF fibers can be strained to more than 40% while fully maintaining their light guiding properties. We investigated POF as a distributed strain sensor by analysing the backscatter increase at the strained section using the optical time domain reflectometry (OTDR) technique. This sensing ability together with its high robustness and break-down strain makes POF well-suited for integration into technical textiles for structural health monitoring purposes. Within the European research project POLYTECT (Polyfunctional textiles against natural hazards) technical textiles with integrated POF sensors, among others sensors are being developed for online structural health monitoring of geotechnical structures. Mechanical deformation in slopes, dams, dikes, embankments and retrofitted masonry structures is to be detected before critical damage occurs. In this paper we present the POF strain sensor properties, reactions to disturbing influences as temperature and bends as well as the results of the different model tests we conducted within POLYTECT. We further show the potential of perfluorinated graded-index POF for distributed strain sensing with increased spatial resolution and measurement lengths.

  8. A Parametric Study of Stability of Geotextile-Reinforced Soil Above an Underground Cavity

    poor, Abbas Tahmasebi; Noorzad, R.; Shooshpasha, E.;


    A study based on two-dimensional finite element analyses under plane strain condition was performed by PLAXIS code to investigate the behavior of geotextilereinforced soil above an underground cavity. The effects of depth of single layer, tensile stiffness, number and length of reinforcement laye...

  9. Construction of subgrade slope protection with geotextile bags and slope protection with geotextile bags and main control points%路基土工模袋护坡施工及控制要点




  10. Cysteine-grafted nonwoven geotextile: a new and efficient material for heavy metals sorption--Part B.

    Vandenbossche, M; Vezin, H; Touati, N; Jimenez, M; Casetta, M; Traisnel, M


    The development of a new material designed to trap heavy metals from sediments or wastewater, based on a polypropylene non-woven covalently grafted with cysteine, has been reported in a previous paper (Part A). The non-woven was first functionalized with acrylic acid (AA) which is used as spacer, and then cysteine was immobilized on the substrate through covalent coupling in order to obtain the so-called PP-g-AA-cysteine. Some preliminary heavy metals adsorption tests gave interesting results: at 20 °C for 24 h and in a 1000 mg/L heavy metals solution, PP-g-AA-cysteine adsorbs 95 mg Cu/g PP (CuSO4 solution), 104 mg Cu/g PP (Cu(NO3)2 solution), 135 mg Pb/g PP (Pb(NO3)2 solution) and 21 mg Cr/g PP (Cr(NO3)3 solution). In this second part of the work, heavy metals sorption tests were carried out with Cu (II), Pb (II), and Cr (III) separately, in order to determine the sorption capacity of this new sorbent as a function of (i) the heavy metals concentration in the solution, (ii) the contact time with the solution, (iii) the pH and (iv) the ionic strength of the solution containing heavy metals. Moreover, the sorption capacity of PP-g-AA-Cysteine was studied using a polluted solution consisting of a mixture of these different heavy metals. An Electron Paramagnetic Resonance study was finally carried out in order to determine the coordination geometry in the environment of the copper trapped by the PP-g-AA-cysteine.

  11. 78 FR 25253 - Foreign-Trade Zone (FTZ) 26-Atlanta, Georgia; Notification of Proposed Production Activity; PBR...


    ... the production of non-woven geotextile fabric using polypropylene fiber. Pursuant to 15 CFR 400.14(b... be able to choose the duty rate during customs entry procedures that applies to geotextile...

  12. 77 FR 16554 - Endangered and Threatened Wildlife and Plants; Receipt of Applications for Incidental Take...


    ... for the installation of a geotextile dune core system (an engineered dune feature constructed with tiered sand-filled geotextile containers as its core that is regularly maintained with 3 feet of...

  13. Geo textiles and related products used in the waterproofing of reservoirs. Situation in Morocco; Geotextiles y productos relacionados utilizados en la impermeabilizacion de balsas. Situacion en Marruecos

    Leiro Lopez, A.; Mateo Sanz, B.


    The aim of this paper is to describe the geo textiles, and products related to geo textiles, used for the building of water-storage reservoirs, which can be applicable to the construction of this kind of structures in Morocco. It presents different types of geo textiles and related products most commonly used in reservoirs, such as geo nets, geo grids, geo mats and geo composites, describing their characteristics and experimental methodology. Furthermore, and drawing on the Spanish Manual for Design, Construction, Operation and Maintenance of Reservoirs, emphasis is placed on the functions that geo synthetics can perform, such as protection and filter in the case of geo textiles, and drainage in the case of geo nets and draining composites. Finally, several works of this sort of structures located in Morocco are cited. (Author)

  14. ジオテキスタイルの垂直方向通水性能に及ぼす見掛けの開孔径の影響についての検討

    木幡, 行宏; 島谷, 文卓; 弘中, 淳市; 平井, 貴雄


    The apparent opening size (O95) of geotextile is a physical parameter closely related to the permeability property and/or amount of clogging of geotextile. In this study, since the apparent opening size is an important parameter, the apparent opening size test of geotextile on the wet method was performed and verified the adequacy of that test method. The apparent opening size of geotextile obtained from that test is discussed. Based on a series of constant head permeability test results on t...

  15. ジオテキスタイルの見かけの開孔径試験方法に関する考察

    木幡, 行宏; 島谷, 文卓; 弘中, 淳市; 平井, 貴雄


    The apparent opening size (O95) of geotextile is a physical parameter closely related to the permeability property and/or amount of clogging of geotextile. In this paper, the various methods for apparent opening size of geotextile are discussed. The apparent opening size tests of geotextile on the wet and hydrodynamic method were performed, and the apparent opening size of each test method was evaluated. Based on test results, an improvement of each test method was proposed. It was found that...

  16. Evaluation of Nondestructive Methods for Determining Pavement Thickness


    Figure 6. Geotextile placement on top of subgrade ................................................................................ 12 Figure A geotextile was placed on the subgrade, prior to placing the subbase and base layers (Figure 6). Drainage was also constructed in the center of...base. Figure 5. Excavation for test site construction preparation. Figure 6. Geotextile placement on top of subgrade. ERDC/GSL TR-11-41 13

  17. Storm Damage Reduction Project Design for Wallops Island, Virginia, Version 1.01


    the rock seawall .......................................................................... 28 3.4.1 Geotextile tube section at south end of seawall... geotextile tube and the overwash area that was previously Assawoman Inlet...30 ERDC/CHL TR-11-9 viii Figure 3-8. Near the middle of the geotextile tube section, looking north

  18. Resistance of Concrete Masonry Walls With Membrane Catcher Systems Subjected to Blast Loading


    effectiveness of systems comprised of polymers, composites, geotextiles , and thin steel and aluminum sheets has been researched extensively over the past...secondary debris resulting from blast pressure, and the effectiveness of systems comprising polymers, composites, geotextiles , and thin steel and aluminum...wall structure undergoes large transient displacements. Initially, relatively stiff composite laminates and geotextiles were investigated, including

  19. The Establishment and Application of the National Standard on the Geotextiles and Geotextiles-related Products Determination of Water Flow Capacity in Their Plane%国标《土工布及其相关产品平面内水流量测定》的制定与应用




  20. Engineering fabrics in transportation construction

    Herman, S. C.


    The following areas are discussed: treatments for reduction of reflective cracking of asphalt overlays on jointed-concrete pavements in Georgia; laboratory testing of fabric interlayers for asphalt concrete paving: interim report; reflection cracking models: review and laboratory evaluation of engineering fabrics; optimum-depth method for design of fabric-reinforced unsurfaced roads; dynamic test to predict field behavior of filter fabrics used in pavement subdrains; mechanism of geotextile performance in soil-fabric systems for drainage and erosion control; permeability tests of selected filter fabrics for use with a loess-derived alluvium; geotextile filter criteria; use of fabrics for improving the placement of till on peat foundation; geotextile earth-reinforced retaining wall tests: Glenwood Canyon, Colorado; New York State Department of Transportation's experience and guidelines for use of geotextiles; evaluation of two geotextile installations in excess of a decade old; and, long-term in situ properties of geotextiles.

  1. Stability Thresholds and Performance Standards for Flexible Lining Materials in Channel and Slope Restoration Applications


    stabilization Select industry term Vegetated reinforced soil slope VRSS A bioengineered system of geotextile -wrapped, vegetated soil lifts USACE...5.1-cm) samples intended for the geotextile fabric industry. When considering results for an application, designers should refer to the minimum...beneath TRM. 4 Non-woven geotextile fabric is recommended beneath ARVS for continuous flow applications and for unvegetated conditions or applications (0

  2. Modeling the Performance of Sand Filters for Removing Runoff Suspended Sediment


    release; distribution is unlimited. Prepared for US Army Corps of Engineers Washington, DC 20314-1000 ERDC/EL CR-13-3 ii Abstract Geotextile tubes...sediments in urban stormwater runoff, and thus should be effective in removing metals in runoff from SAFRs. Porous geotextile fabric is used to hold...public release; unlimited distribution. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Geotextile tubes filled with sand are being evaluated for filter

  3. Final Environmental Assessment for the Bridge Replacement and Scour Protection Measures at Avon Park Air Force Range, Florida


    Scour protection measures would consist of backfill soil overlaid with geotextile plastic and then aggregate (broken concrete). The backfill soil...canal is scouring underneath these footers. The scour protection methods would include placement of fill and plastic geotextile overlaid with...back the earthen berm of Kissimmee Road. The riprap, geotextile and concrete aggregate would be placed at the interface between the canal floor

  4. Barren Island Dredged Material Placement for Regional Sediment Management


    the island are extensive sea grass beds dominated by Ruppia maritima. Although geotextile tubes have been installed and some wetland restoration has...exceedingly costly, geotextile tubes were used at Bar- ren Island to contain the sediment as a less expensive alternative. Baltimore District desired...out of the placement site. After several discussions with various manufacturers of the geotextile tubes, Baltimore District ERDC/CHL CHETN-XIV-21

  5. ジオテキスタイルフィルターの目詰まり特性

    木幡, 行宏


    When a geotextile as filter is set in a ground for drainage, a decreasing of cross-plane flow performance of geotextile is expected due to a clogging associated with a intrusion and capture of soil particle. The objective of this paper is to consider a suitable geotextile filter to be hard to arise a clogging for fine-grained soils at a field site. This study was performed to focusing on a change of coefficient of permeability normal to plane on a kind of geotextile filter. A series of consta...

  6. 構造が異なるジオテキスタイルフィルターの垂直方向透水性に関する検討

    木幡, 行宏; 蒲生, 夏希; 弘中, 淳市; 平井, 貴雄


    The objective of this study is to consider a suitable geotextile filter to be hard to arise a clogging for fine-grained soils at a field site. This study was performed to focusing on a change of coefficient of permeability normal to plane on a kind of geotextile filter. A series of constant head permeability test on woven fabric geotextile filter was performed sandwiching in a geotextile filter between fine-grained geomaterial and gravel layer. Based on the test results and formally test resu...

  7. Rational design approach for landfill liner protective soil cover

    Ruetten, M.G. [STS Consultants Ltd., Green Bay, WI (United States); Bandi, S.R. [Rust Environment & Infrastructure, Livonia, MI (United States); Reddy, K.R. [Univ. of Illinois, Chicago, IL (United States)


    This paper presents a rational approach for designing protective soil cover for landfill geomembrane liners in order to prevent damage to the liners. The present practice involves using a combination of geotextile and soil layer as protective cover. The geotextile is placed directly over the geomembrane and then a protective soil is placed on the geotextile. The protective soil layer generally consists of a free-draining granular soil which also serves as a drainage layer for the leachate collection and removal system. The degree of protection offered to the geomembrane depends on the type of geotextile, and the composition and thickness of the protective soil used.

  8. Application of Geotextile Net for Foundation Stabilization Used in Madu Vulnerable Spot%土工网网罩固根技术在马渡险工的应用

    张遂芹; 边鹏; 李老虎; 尚青松



  9. 非织造土工织物用于公路补强时的弹塑性损伤计算%The Calculation of Elastoplastic Damage with Non-woven Geotextiles Used in Road Reinforcement

    潘宝峰; 王海清; 原田; 项伯威



  10. The Application of Hasty Geotextile-concrete Blockwork in the Shore Protection for Oil Pipeline%简易模袋混凝土护坡技术在输油管道上的应用

    何悟忠; 董仲智; 郭庆茹; 吴运强; 宫明



  11. Evaluation of Techniques to Eliminate Erosion from Under River Revetment Mattresses


    geotextiles. (a) (b) Figure 9. Photomnicrographs showing (a) woven and (b) nonwoven geotextile fibers. R.M. Koerner. Designing with Geosynthetics (Prentice...Engineering Research Laboratory, January 1976). Koerner, R.M., Designing With Geosynthetics (Prentice-Hall. 1986). Torrey III, Victor H., Joseph B. Dumbar

  12. Transmissivity evolution through interface of composite liners under applied constraint.

    Diagne, M


    In landfill liners, geomembranes have defects that constitute preferential passages of leachate from rainwater percolation. Non-woven geotextiles are widely used in wastelandfills as materials having the functions of protection, separation, filtration and drainage. This study seeks to select geotextiles through an investigation conducted among landfill operators who commonly arise a geotextile in the geomembrane-clay interface to facilitate geomembrane welding and to prevent its puncture by angular materials. It also attempts to find out the influence of geotextile in a decimetric transmissivity cell size under 50 kPa stress and smooth ground surface. The results show that the transmissivity in composite liner interface is almost the same as the one calculated with the European standard EN ISO 12958. Transmissivity depends on the mechanical stress applied to the bottom liner, on the geotextile type in the interface and on the ground surface.

  13. Laboratory evaluation of geosynthetic fabric containers for contaminant migration

    Moo-Young, H.; Ochola, C.


    There exist various methods to determine the filtration properties of geotextiles, and most of these methods are based on the Apparent Opening Size (AOS) or O{sub 95} value as designated by ASTM D-4751 ``Standard Test Method for Determining Apparent Opening Size of a Geotextile''. The ability of a geotextile to function as an effective filter is dependent on the granularity of the medium being filtered, hydraulic conditions, and the configuration of the pore spaces within the geotextile. Current methods to determine the AOS do not take into consideration the various strains that the geotextiles may experience in the field, and are therefore based on static conditions or under no strain which may not be representative of what happens to a geotextile when in use. The utilization of GFC's to reduce the movement of contaminated sediments have necessitated the investigation of the migration of fines through various geotextile configurations used to construct the GFCs, and to determine the amount of total suspended solids that would be released. This laboratory study investigates the migration of fines and contaminants through GFCs. Contaminated dredges sediment was characterized for the physical and chemical properties. Hanging bag tests, barge simulation tests, fabric analysis strain tests, and pressure filtration tests with varying strain were conducted on the contaminated sediment and GFC configurations to determine the amount of total suspended solids that would be released to the water column.

  14. 種々の土質を用いた透水試験によるジオテキスタイルフィルターの目詰まり特性

    木幡, 行宏; 佐藤, 織絵; 島谷, 文卓; 弘中, 淳市; 平井, 貴雄


    A series of constant head permeability test was performed by putting in a geotextile between a geomaterial layer and a gravel layer in order to evaluate an effect of geomaterial on the cross-plane flow performance of geotextile filter. As the geomaterials for this study, Ataka loam, Kanto loam, Rokunohe sand with fine-grained and Muroran sand with fine-grained were prepared. Based on test results, it was found that the cross-plane flow performance of geotextile depended on the relationship be...

  15. Permeable Pavement Research at NRMRL’s Urban Watershed Research Facility (Poster 2)

    Assess pollutant removal efficiency of porous pavement systems with regard to parking lot runoff. Bench-scale study will examine: Discharge volume Flow rate Total suspended solids (TSS) of influent vs. effluent Use of a geotextile permeable filter fabric...


    The amendments apatite, organoclay, acetate, chitin, and geotextile reactive mats containing apatite and apatite + organoclay are currently under examination for remediation of contaminated sediments. The objective of this research is to evaluate toxicity to several estuarine an...

  17. Experimental evaluation of drainage filters sealing in peat soils

    Nevzorov Aleksandr Leonidovich


    Full Text Available The article deals with research results of the sealing of pores in drainage filters by organic particles. Permeability tests were carried out with the constant gradient 1.5. The water flow through the sample of soil was top-down.The tests were carried out with 2 types of samples: the first part of samples had layers (from up to down 300 mm peat and 2 layers of geotextile, the second part consisted of 250 mm peat, 200 mm fine sand and 2 layers of geotextile. Well decomposed peatsamples were used. Peat had the following characteristics: density is 1,05...1,06 g/cm3, specific density — 1,53...1,56 g/cm3, void ratio — 12,0...12,5. The duration of each test was 15 days. During testing the hydraulic conductivity of samples was decreased by 1.3...1.9.After completing the tests the hydraulic conductivity of sand and geotextile were measured. The content of organic matter in geotextile and fine sand was determined as well. Dry mass of organic matter in the first layer of geotextile in the first type of samples were 1,0…1,3 g per 75 cm2. The organic matter in the second layer of geotextile in the first type of samples and in the first layer of geotextile in the second type wasn’t exposed. Fine sands protected the drainage geotextile as a result of sealing of pore space of sands by organic matter.

  18. Application of an ancient Chinese algorithm to stab performance of woven fabrics

    Wang Ping


    Full Text Available Stab damage is a common failure mode for textile products, especially for the geotextiles and geotextile-related products which are widely used in the road, airport, pipeline, and so on. In this paper, an ancient Chinese algorithm is applied to predict the stab area and stab energy of woven fabrics under stabbing load according to the load-displacement performance of the single yarn. This research proposes a novel method to analyze the stab property of the textile products.


    Subianto Tjandrawibawa


    Full Text Available It was common practice to apply a layer of ''sirtu'' (sandy gravel beneath the shallow foundations of buildings on soft subsoil. Though the bearing capacity is increased, it is usually limited to anticipate future consolidation settlements which might be detrimental. This could be overcome by reinforcing the ''sirtu'' layer with geotextiles. To study the effect of geotextile reinforcement, a laboratory foundation model was constructed on a soft soil deposit. The model measured 5x5x2cm³. The bearing capacity of this model was compared with the bearing capacity of the model on ''sirtu'' layer, and geotextile reinforced ''sirtu''. Geotextile reinforcement was laid in one, two and three layers. Based on the bearing capacity tests, it is concluded that with one geotextile layer the strength was increased 182,6% higher than soft soil, with two geotextile layers the strength increased 197,8% higher than soft soil and with three geotextile layer the strength increased 241,3% higher than soft soil. Abstract in Bahasa Indonesia : Bangunan di atas tanah yang lunak sering menggunakan lapisan sirtu di bawah pondasi dangkalnya. Cara ini dapat meningkatkan daya dukung pondasi namun daya dukung ini masih harus dibatasi untuk menghindari kemungkinan penurunan jangka panjang yang merugikan. Penurunan lapisan sirtu sendiri dapat ditanggulangi dengan memasang perkuatan berupa lapisanlapisan geotekstil di dalamnya. Sebuah model dibuat di laboratorium untuk mempelajari efektifitas lapisan-lapisan geotekstil ini terhadap peningkatan daya dukung. Model pondasi berukuran 5x5x2cm³. Daya dukung model ini, langsung di atas tanah lunak, dibandingkan dengan daya dukung model pondasi yang terletak pada lapisan sirtu dan lapisan sirtu yang diperkuat geotekstil. Lapisan sirtu diperkuat dengan satu, dua sampai tiga lapis geotekstil. Hasil percobaan menunjukkan dengan satu lapis geotekstil kekuatan meningkat sebesar 182,6% dibanding tanah lunak, dengan dua lapis geotekstil

  20. Performance of innovative textile biofilters for domestic wastewater treatment.

    Spychała, Marcin; Błazejewski, Ryszard; Nawrot, Tadeusz


    Two types of geotextile, TS 50 and TC/PP 300, were investigated as experimental filters. The raw wastewater, pre-treated in a septic tank, was intermittently dosed and filtered under hydrostatic pressure. At the beginning, the filter reactor comprised nine filters made of geotextiles (of three types: TS 10, TS 50 and TC/PP 300). At the end of the start-up period the TS 10 filters were removed due to their high outflow instability. After four months of working, the hydraulic capacities of the remaining filters were: 3.23 cm3/cm2/d for TS 50 and 4.14 cm3/cm2/d for TC/PP 300. The efficiencies of COD and BOD5 removal were similar for both types of geotextile (COD: 64%, BOD5: 80%). A small but statistically significant difference between ammonium nitrogen removal was observed (40% for TS 50 and 35% for TC/PP 300), most probably due to their different structure. Biological removal of P(tot) was relatively poor and similar for both geotextile types. The mean concentration of matter accumulated on the geotextiles was over one order of magnitude higher than conventional activated sludge concentrations. During the last weeks of the experiments the values of basic pollution indicators in the effluent were lower than the maximum permissible values (according to Polish law).

  1. Flyash disposal problems at thermal power stations - an experimental study

    Reddy, E.S.; Peter, E.C. Nirmala; Sastri, K. Rama [JNTU Coll. of Engineering, Dept. of Civil Engineering, Hyderabad (India); Kura, Bhaskar [New Orleans Univ., Dept. of Civil and Environmental Engineering, New Orleans, LA (United States)


    Disposal of flyash at thermal power stations is carried out in the form of ash slurry by mixing the ash with water. The ash slurry is stored in an ash pond. The water in the slurry is gradually drained out, through decanting wells, earthen embankments and over spillways, leaving the ash to deposit in the pond. It is observed that, the design of decanting wells presently being used allows a considerable amount of flyash to flow out with water, leading to the contamination of soil and the water courses. Further, it is observed that, the failure of earthen bunds of ash ponds, which results in a major damage to the environment, is mainly due to ineffective functioning of filters in the bunds. This paper presents the details of an experimental investigation carried out to study the role of geotextiles in improving the performance of decanting wells and earthen bunds. Two series of experiments were carried out. In the first series two model decanting wells were tested with geotextile lining. In the second series, a number of model earthen bunds were tested with and without geotextiles. Economics of providing geotextiles in earthen bunds is studied. The results indicated that, the use of geotextiles is economical and effective improving the performance of decanting wells and the earthen bunds of an ash pond. (Author)

  2. Flyash disposal problems at thermal power stations - an experimental study

    Reddy, E.S.; Peter, E.C.N.; Sastri, K.R.; Kura, B. [JNTU College of Engineering, Hyderabad (India). Dept. of Civil Engineering


    Disposal of fly ash at coal-fired power stations is carried out in the form of ash slurry by mixing the ash with water. The ash slurry is stored in an ash pond. The water in the slurry is gradually drained out, through decanting wells, earthen embankments and over spillways, leaving the ash to deposit in the pond. The design of decanting wells presently being used in power stations, such as Vijayawada in India allows a considerable amount of flyash to flow out with water, leading to the contamination of soil and the water courses. Further, the failure of earthen bunds of ash ponds, which results in a major damage to the environment, is mainly due to ineffective functioning of filters in the bunds. This paper presents the details of an experimental investigation carried out to study the role of geotextiles in improving the performance of decanting wells and earthen bunds. Two series of experiments were carried out. In the first series two model decanting wells were tested with geotextile lining. In the second series, a number of model earthen bunds were tested with and without geotextiles. Economics of providing geotextiles in earthen bunds is studied. The results indicated that, the use of geotextiles is economical and effective in improving the performance of decanting wells and the earthen bunds of an ash pond. 15 refs., 10 figs., 6 tabs.

  3. Geocontainers in road building and hydraulic engineering construction


    Geocontainers are structural loops made of high-strength geotextile. In the course of construction they are filled by ground or inert material on-site. The geomatrix is the next step in the development of geocontainers. It is the cellular structure made of geotextile, the cellules are connected by lacing or by thermal welding.The aim of the article is to acquaint the reader with this type of geomaterials, possibilities of its use in different areas of construction.The technology of using geoc...

  4. Relationship Between Structure and Viscoelastic Properties of Geosynthetics

    Loginova Irina


    Full Text Available In this work, a study on viscoelastic properties of geosynthetic materials used in civil engineering is presented. Six samples of geofabrics and geogrids with different structures including woven geotextile fabric, nonwoven geotextile fabrics, warp-knitted geogrids and extruded geogrid were investigated. The tensile properties of geosynthetics including tensile strength, strain at maximum load and tensile load at specified strain have been determined. The creep and relaxation tests were carried out. The structure type was found to significantly affect the viscoelastic properties of the geosynthetics materials. In the article some results of numerous conducted tests are presented, analyzed and may be used to preselection of geosynthetics materials.

  5. Permeable Pavement Research at NRMRL’s Urban Watershed Research Facility

    The results of a bench-scale study of a porous pavement parking lot. Flow rates and total suspended solids (TSS) removal are discussed for systems with a geotextile filter fabric liner in place and those without. The systems with a liner have ~20% better TSS removal performance a...

  6. Pæleorm, Teredo navalis L's nedbrydning af submarint arkæologisk organisk materiale

    Eriksen, Anne Marie; David, Gregory; Botfeldt, Knud Bo


    farvand er det Teredo navalis, som er den mest udbredte. T. navalis lever sit voksenstadie ved at bruge sine skaller til at borer i trre og herigennem nedbryde og optage cellulose. Den optager ogsa ilt og plankton fra de omkringvrerende vandmasser. I denne analyse undersoges to forskellige geo-textiler...

  7. Effects of landscape fabrics on pest control in a raised-bed trough system for strawberry production without fumigation

    Landscape fabrics are geotextiles that have been used to control weeds. The objective of this study was to determine the performance of landscape fabrics for the control of nematodes and fungal pathogens for strawberry fruit production. Four different commercially available landscape fabrics were us...

  8. LABORATORY RESEARCHES OF GEOSYNTHETIC MATERIALS Лабораторные испытания геосинтетических материалов

    Kirsanov A. A.


    Full Text Available The article deals with the problem of overgrowing of ponds and reservoirs. One way to reduce the intensity of development of plants is covering the territory with geosynthetic materials. Laboratory researches of geosynthetic materials are carried out. The optimum size of the layer of soil, which is loading geotextiles, was determined

  9. 78 FR 54234 - Foreign-Trade Zone 26-Atlanta, Georgia, Authorization of Production Activity PBR, Inc. d/b/a...


    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 26--Atlanta, Georgia, Authorization of Production Activity PBR, Inc. d/b/a SKAPS Industries (Polypropylene Geotextiles), Athens, Georgia On April 8,...

  10. Engineer: The Professional Bulletin of Army Engineers. Volume 38, PB 5-08-3/4, July-December 2008


    determine where he’d be able to make the “big- gest bang for his buck .” He concluded that he would engage several military colleges at the strategic...alike, the reduction of even one vehicle in a convoy is a real morale booster . During the project, more than 16 kilometers of geotextile cells were

  11. In-depth improvement of soil at the base of roads on taliks

    Alexey Y Burukin; Svyatoslav Ya Lutskiy; Konstantin N Khripkov


    The article presents a new technological solution to improve the safety of embankment bases on taliks during construction periods. The use of geotextile-sleeved sand columns and geogrids on low-temperature permafrost is investigated. The correlations between mechanical and temperature processes under this in-depth base improvement method are calculated.

  12. Proceedings of the 22nd symposium on engineering geology and soils engineering


    This book presents the papers given at a symposium on soil mechanics and engineering geology. Topics considered at the symposium included geotechnical testing and site exploration, design, soil dynamics, geotextiles, earthquake and volcanic hazard studies, slope stability and landslides, seismic considerations in geotechnical engineering, hazardous substances disposal, ground water, environmental and urban geology, and the response of the Boise geothermal aquifer to earth tides.

  13. Folosirea pământului armat la fundaţii pe terenuri slabe

    Felicia Enache Niculescu


    Full Text Available The geosynthetics term is generally regarded to encompass eight main product categories: geotextiles, geogrids, geonets, geomembranes, geocomposites, geocells and combinations of materiales. These synthetic polymeric can be fabricated from hight resistences, deformation needetand a good adherence with earth confinement.

  14. Geodetect: a new step for the use of fibre Bragg grating technology in soil engineering

    Voet, Marc R.; Nancey, Alain; Vlekken, Johan


    Geodetect is an innovative geotextile-based monitoring system, developed for the measurement of strain and deformation of earthwork structures reinforced with geosynthetics. This paper presents the background and the results of the development and the practical experience acquired in real time jobs with this new technology.

  15. Experimental study of reinforced expansive soil slope in freeze-thaw environment%冻融环境下加筋膨胀土边坡力学模型试验与研究

    徐丽丽; 张滨; 李兆宇; 吴志琴


    针对寒区膨胀土边坡冻胀问题,提出采用土工织物加筋处理技术。通过加筋处理及未处理两组室内冻土力学模型试验对比分析,研究在冻融循环作用下土工织物加筋膨胀土边坡的运行机制和效果。试验结果表明:①在土体冻结过程中,未处理的膨胀土边坡不均匀冻胀明显,土工织物加筋能有效抑制结构不均匀冻胀;②土工织物对水分的迁移有阻隔作用,加筋土处理模型的冻深略大于未处理模型;③碎石聚氨酯固脚具有一定的保温防冻胀作用。%For freeze injury of expansive soil slope , a technology using geotextile reinforced was handled .In accordance with the comparation and analysis of the treated and untreated frozen mechanical model test , the operation mechanism and effects of geotextile-reinforced expansive soil slope under freezing thaw cycle conditions are analyzed.Conclusion: ① In the process of soil freezing , untreated expansive soil slope uneven heaving obvious, geotextile-reinforced structure can effectively suppress uneven frost heave; ②Geotextile can block water migration in the soil , frozen deep of geotextile-reinforced model is slightly larger than the untreated models; ③Elastocoast can increase heat resistance;the Elastocoast protection-foundation has heat preservation effect .

  16. Erosion Control and Recultivation Measures at a Headrace Channel of a Hydroelectric Power Plant using Different Combined Soil Bioengineering Techniques

    Obriejetan, M.; Florineth, F.; Rauch, H. P.


    As a consequence of land use change resulting in an increased number of slope protection constructions and with respect to effects associated with climate change like extremes in temperatures and temperature variations or increased frequency of heavy precipitation, adaptation strategies for sustainable erosion protection systems are needed which meet ecological compatibility and economical requirements. Therefore a wide range of different technical solutions respectively geotextiles and geotextile-related products (blankets, nettings, grids etc.) are available on the market differing considerably in function, material, durability and pricing. Manufacturers usually provide product-specific information pertaining to application field, functional range or (technical) installation features whereas vegetational aspects are frequently neglected while vegetation can contribute substantially to increased near-surface erosion protection respectively slope stability. Though, the success of sustainable erosion control is directly dependent on several vegetational aspects. Adequate development of a functional vegetation layer in combination with geotextiles is closely associated to application aspects such as seeding technique, sowing date and intensity, seed-soil contact or maintenance measures as well as to qualitative aspects like seed quality, germination rates, area of origin, production method or certification. As a general guideline, erosion control within an initial phase is directly related to restoration techniques whereas vegetation specifics with regard to species richness or species composition play a key role in medium to long-term development and slope protection. In this context one of the fundamental objectives of our study is the identification and subsequently the determination of the main interaction processes between technical and biological components of combined slope protection systems. The influence of different geotextile characteristics on specific

  17. Effectiveness of porous covers for control of ammonia, reduced sulfur compounds, total hydrocarbons, selected volatile organic compounds, and odor from hog manure storage lagoons.

    Regmi, Shekhar; Ongwandee, Maneerat; Morrison, Glenn; Fitch, Mark; Surampalli, Rao


    Anaerobic lagoons are a major source of odor at concentrated animal feeding operations. Seven different kinds of artificial (geotextile and polyethylene foam) and natural (straw and redwood) permeable lagoon covers were evaluated for their potential to reduce odorous emissions generated by anaerobic waste lagoons. A novel floating sampling raft was constructed and used to simultaneously evaluate the effectiveness of lagoon covers on an operating swine waste lagoon. The air collected from the raft was evaluated for odor, total reduced sulfur (TRS) compounds, ammonia, total hydrocarbons, dimethyldisulfide, and trimethylamine. The emission rates from the lagoon were highly variable both temporally and spatially. All of the lagoon covers substantially reduced TRS emissions and odor. Geotextile fabric and a recycled foam cover exhibited the greatest reduction in total hydrocarbon emissions; natural covers were less effective. Because of consistently low emission rates of ammonia, no statistically significant reduction of ammonia emissions were observed from any of the lagoon covers.

  18. Numerical modeling of consolidation processes in hydraulically deposited soils

    Brink, Nicholas Robert

    Hydraulically deposited soils are encountered in many common engineering applications including mine tailing and geotextile tube fills, though the consolidation process for such soils is highly nonlinear and requires the use of advanced numerical techniques to provide accurate predictions. Several commercially available finite element codes poses the ability to model soil consolidation, and it was the goal of this research to assess the ability of two of these codes, ABAQUS and PLAXIS, to model the large-strain, two-dimensional consolidation processes which occur in hydraulically deposited soils. A series of one- and two-dimensionally drained rectangular models were first created to assess the limitations of ABAQUS and PLAXIS when modeling consolidation of highly compressible soils. Then, geotextile tube and TSF models were created to represent actual scenarios which might be encountered in engineering practice. Several limitations were discovered, including the existence of a minimum preconsolidation stress below which numerical solutions become unstable.

  19. Erective Sea Embankment with PCC Piles

    LIU Han-long; FEI Kang; DENG An; ZHANG Ting


    The sea embankment is a critical civil works in marine and coastal engineering. In this study, an innovative technique is proposed for constructing erective sea embankments. In the construction of sea embankments, this technique integrates PCC pile installation, PVDs drainage systems, and geotextile reinforcements, resulting in sea embankments with PCC piles. In the application of a sea embankment with PCC piles, PCC piles are employed as the retaining structures;the soft sea ground inside PCC piles is drained and improved by PVDs and vacuum-surcharge combined preloading; geotextile-reinforced backfills lying over the improved soft ground form the embankment body. Brief descrptions of the fundamentals, design and construction of the sea embankment with PCC piles are presented. A case study on the stability of sea embankment with PCC piles is presented as well.

  20. Long-term analysis of clogging and oil bio-degradation in a System of Catchment, Pre-treatment and Treatment (SCPT).

    Fernández-Barrera, Andrés H; Castro-Fresno, Daniel; Rodriguez-Hernandez, Jorge; Vega-Zamanillo, Angel


    Runoff contamination has motivated the development of different systems for its treatment in order to decrease the pollutant load that is discharged into natural water bodies. In the long term, these systems may undergo operational problems. This paper presents the results obtained in a laboratory study with a 1:1 scale prototype of a System of Catchment, Pre-treatment and Treatment (SCPT) of runoff waters. The analysis aims to establish the operational behaviour of the SCPT in the long term with respect to oil degradation and hydraulic conductivity in the geotextile filter. It is concluded that bio-degradation processes take place inside the SCPT and that hydraulic conductivity of the geotextile filtration system decreases slowly with successive simulated runoff events.

  1. Sustainable Approaches for Stormwater Quality Improvements with Experimental Geothermal Paving Systems

    Kiran Tota-Maharaj


    Full Text Available This research assesses the next generation of permeable pavement systems (PPS incorporating ground source heat pumps (geothermal paving systems. Twelve experimental pilot-scaled pavement systems were assessed for its stormwater treatability in Edinburgh, UK. The relatively high variability of temperatures during the heating and cooling cycle of a ground source heat pump system embedded into the pavement structure did not allow the ecological risk of pathogenic microbial expansion and survival. Carbon dioxide monitoring indicated relatively high microbial activity on a geotextile layer and within the pavement structure. Anaerobic degradation processes were concentrated around the geotextile zone, where carbon dioxide concentrations reached up to 2000 ppm. The overall water treatment potential was high with up to 99% biochemical oxygen demand removal. The pervious pavement systems reduced the ecological risk of stormwater discharges and provided a low risk of pathogen growth.


    Teodor Eugen Man


    Full Text Available Geosynthetics is the term used to describe a range of generally polymeric products used to solve some civil engineeringproblems. The term is generally regarded to encompass eight main product categories: geotextiles, geogrids, geonets,geomembranes, geosynthetic clay liners, geofoam, geocells (cellular confinement and geocomposites. The syntheticpolymeric nature of these products makes them suitable for use in the ground where high levels of durability arerequired. Not only because, properly formulated, they can also be used in exposed applications. Geosynthetics areavailable in a wide range of forms and materials, each to suit a slightly different end use. These products have a widerange of applications and are currently used in many civil, geotechnical, transportation, geoenvironmental, hydraulic,and private development applications including roads, airfields, railroads, embankments, retaining structures,reservoirs, canals, dams, erosion control, sediment control, landfill liners, landfill covers, mining, aquaculture andagriculture. The paper presents basic aspects of geotextiles, drainage, geocomposite designissues and technicalsolutions of their use.

  3. Discussion on stability analysis of bagged-sand dike at Yangtze River estuary%长江口袋装砂围堤稳定分析方法探讨

    彭良泉; 李令长


    To obtain more convenient and practical stability analysis method for geotextile bagged-sand dike, we analyze the reinforcement mechanism of geotextile bagged-sand dike according to several dike projects in Yangtze River estuary, and the disadvantages of conventional stability analysis method for bagged-sand dike are pointed out, and the formula of quasi-cohesive force of bagged-sand dike is deduced theoretically. The examples show that the stability analysis of bagged-sand dike using quasi-cohesive force takes account the beneficial effects of reinforcement of geotextile and the defects that the limit equilibrium method could not consider influence from geotextile deformation on stability analysis. The presented method has valuable mean-ings to stability analysis of bagged-sand dike on soft foundation.%为使土工织物袋装砂围堤的稳定计算简单易行且更加符合实际,针对长江口袋装砂围堤工程,分析了袋装砂围堤土工织物的加筋机理,指出了常规袋装砂围堤稳定分析方法存在的缺陷,从理论上导出了袋装砂围堤拟凝聚力公式。算例表明,利用拟凝聚力进行围堤稳定分析,既充分考虑了土工织物加筋对围堤稳定的有利影响,又修正了极限平衡法不能直接考虑土工织物变形对稳定分析影响的缺陷。对软基袋装砂围堤工程的稳定分析具有一定的指导意义。




    Full Text Available Some techniques can be used in order to promote the recovery of degraded areas like riverine ecosystems, and those with low impacts present a fast regeneration, through an ecological succession with no need for human intervention. It is necessary to study the use of techniques that contribute to the recovery of these ecosystems, such as soil bioengineering, which involves the use of biologically active elements working on soil stabilization, combined with inert elements such as concrete, wood, polymers, and geotextiles made with synthetic material or plant fibers. This work was carried out in order to evaluate planted species develop- ment and endemic species in the ecological succession, along the Paramopama river margin, located at the mu- nicipality of São Cristóvão, in Sergipe State, submitted to soil bioengineering techniques. Two types of geotex- tiles (Fibrax and Syntemax and 400 TF arranged in two blocks and three treatments were tested, and the be- havior of the vegetation and efficiency of geotextiles were observed for a period of 11 months monitored by the floristic survey. The abundance of the species Crotalaria spectabilis and Calopogonium muconoides was stud- ied, and subsequently classified according to vegetation succession stage. The study revealed that the use of geotextile Syntemax 400 TF on the left bank promoted the greatest abundance of species, resulting in a greater vegetation cover, and consequently better protection of the slope. The geotextile Syntemax 400 TF was the most appropriate among the tested types, to promote the floristic recovery in the studied area and probably in those with similar soil-climatic conditions.

  5. Compaction and stressing - a new stabilisation concept for deep shafts; Verdichten und Verspannen - ein neuartiges Sicherungskonzept fuer tiefe Schaechte

    Daude, E.; Ossenbuehl, I. [Gebhardt und Koenig Berg- und Bautechnik GmbH, Recklinghausen (Germany); Scherbeck, R. [TABERG Ingenieure GmbH, Luenen (Germany)


    Placing Bullflex-geotextiles in boreholes from ground level is part of a new stabilization technique for deep old shafts filled up with non cohesive materials. Bullflex-elements increase the material's density when filled with cement-based grout under pressure by radial movements of the fill material. The global stability of an old shaft can be analyzed easily when relying on results from Bullflex installations actually proved by measurements. (orig.)

  6. MULTITEXCO - high performance smart multifunctional technical textiles for tensile structures

    Heyse, P.; Buyle, G; Beccarelli, Paolo


    In recent years, the textile industry developed a new generation of advanced textile materials for the construction sector designed to address the needs of one of the largest markets for textile products. Examples of the advanced textiles developed include fabrics for the rehabilitation of buildings, geotextiles for the consolidation of a wide range of soil structures and the high performance technical textiles for tensile structures. When combine with innovative sensors the fabrics provide a...

  7. U.S. Air Force: Inadequately Prepared for Forward Operations in a Combat Environment


    mechanics with the proper maintenance technical orders. The other major problem with deployable fuel systems was leaking bladders. Again, the extreme...are available. First article testing was scheduled for the spring of 2005 with production models available in FY06.29 Convoy operations appear to...with non-woven polypropylene geotextile . For more information refer to: 14 Peter Brownfeld., “U.S

  8. Combined Wave and Surge Overtopping of Levees: Flow Hydrodynamics and Articulated Concrete Mat Stability


    technical report describes small-scale physical model tests simulating combined wave and storm surge overtopping of a typical levee cross sec- tion of...journal article . The 2 percent run-up elevation should be estimated using the run-up formulas of de Waal and van der Meer (1992) or Hughes (2004). If place the mats over some type of filter layer ( geotextile or stone filter) that prevents the levee or embankment soil from leeching out between

  9. Defense Logistics Agency’s Warstopper Program


    Support ($11.7 million), and Construction and Equipment ($3.3 million) contracts. We did not examine Warstopper funding related to contracts barrier consisting of a prefabricated, multicellular system made of a welded steel-wire mesh, heavily galvanized, with a nonwoven geotextile...chamber. DLA decided to fund the construction of an additional Nesatron chamber with the option to sell it to the contractor at fair market value at

  10. Annual National Test and Evaluation Conference (27th) Held in Tampa, Florida on March 14-17, 2011


    Permanent • 3-7 year life • Permeable / Environmentally Friendly • Can be paved later DISTRIBUTION STATEMENT D RC UAV Distribution Statement A...Geotextile Surface • Use landscape stakes or nails with washers on 1-2ft centers • Fold horizontal seams and nail • Do not pull fabric too tight...Leave some minor wrinkles • Sun will heat and stretch surface ‘drum tight’ 8” Nail with washer Distribution Statement A Striping the


    M. Andal; Chandrasekhar, M.; G. K. Viswanadh


    This paper presents the influence of partial replacement of bentonite by silica fume which is used in the manufacture of Geosynthetic Clay Liner (GCL). Geosynthetic Clay Liners consist bentonite (Sodium Based) sandwiched between two geotextile. Benotinite, having low permeability imparts better hydraulic performance to the GCL to act as liner. In this investigation, an attempt has been made to study the hydraulic conductivity of GCL with modified Bentonite. The bentonite is partially replaced...

  12. Beneficial impact of polymer treatment of Ca-bentonites on long term hydraulic conductivity

    Di Emidio, Gemmina; De Camillis, Michela; Bezuijen, Adam; Verastegui Flores, R.D.


    The hydraulic conductivity of geosynthetic clay liners for the confinement of waste disposal facilities mainly depends on the hydraulic conductivity of the core bentonite clay encased between the two geotextiles. Bentonite clay is the most common material for geosynthetic clay liners. Even thought, sodium bentonite has the lowest hydraulic conductivity to water, calcium bentonite is widely used because of low cost and availability. This research concerns the evaluation of the treatment of cal...

  13. Marginal Aggregates in Flexible Pavements: Background Survey and Experimental Plan


    cement, bitumen , and water has been marketed in France under the trade name Stabicol 71 , but it is not yet available in the U.S. This a pavement base course. Geotextile reinforcement and a new portland cement- bitumen emulsion have considerable potential to upgrade substandard...modifiers with SBS , polyethylene. 30 b) Hard Asphalt Cement - AC 40 asphalt cement. c) Large Stone Asphalt Mixtures - Increase maximum aggregate size. e

  14. A fiber optics textile composite sensor for geotechnical applications

    Artières, Olivier; Dortland, Gerrit


    The fiber optics in structural health monitoring systems for civil engineering applications have been widely used. By integrating fiber optic sensing into a geotextile fabric, the TenCate GeoDetect® system is the first designed specifically for geotechnical applications. This monitoring solution embodies fiber optics on a geotextile fabric, e.g. a textile used into the soil, and combines the benefits of geotextile materials, such as high interface friction in contact with the soil, with the latest fiber optics sensing technologies. It aims to monitor geotechnical structure and to generate early warnings if it detects and localizes the early signs of malfunctioning, such as leaks or instability. This is a customizable solution: Fiber Bragg gratings, Brillouin and Raman scattering can be built into this system. These technologies measure both strain and temperature changes in soil structures. It can provide a leak and deformation location within accuracies resp. 1 l/min/m and 0.02%. The TenCate GeoDetect® solution provides objective, highly precise, and timely in-situ performance information, allowing the design professional and owner to understand system performance in addition to providing alerts for negative "geo-events" (subsidence) and other potentially deleterious events.

  15. 黏性土渗透淤堵室内模拟试验及分析%Laboratory model tests and mechanism of infiltration clogging effect of clayey soil

    翟超; 郭伟锋; 严驰


    The gradation of clay, pore sizes of geotextiles, hydraulic gradient and soil compaction are preliminarily studied. According to the test results of clogging gradient, the clogging situations of geotextiles are analyzed under different apertures, clay contents, dry densities and hydraulic gradients. Through model tests, it may provide reference for future practice of geotextiles in different projects.%从黏性土的级配、土工织物的孔径大小、水力梯度和黏性土干密度等因素考虑,根据淤堵试验得出的梯度比的数据,分析土工织物在不同孔径大小、不同黏粒含量、不同黏性土干密度、不同水力梯度条件下的淤堵情况,根据所得试验结果,为今后不同工程对土工织物的选择提供一定参考。

  16. Effect of Death Mulching Methods to Weed Coverage in Mandarin Orchard

    Onur Kolören


    Full Text Available The possible use of three different thickness black geotextile materials (GEO-50, GEO-100 and GEO-150 , the new control methods for our country, compared with weedy check among of the rows and using herbicide (Glyphosate, mowing, black polyethylene with weedy check on the rows have been investigated for controlling of weeds which is a considerable problem of tangerine orchard. Experimental randomly plots were arranged by considering complete block design with five replications on the rows treatment. Mulch materials were applied apart for width of 160 cm on the rows. When weed coverage (% reached 10-15%, herbicide (Glyphosate was applied with 600 cc/da. Mowing was applied when weed lenght and coverage (% reached 10-15 cm and 10-15, respectively. Weed coverage (% and numbers were counted in 15 days intervals at the quadrats for all plots. The results of the studies for tangerine orange 4 years old showed that mulching with black geotextile and polyethylene were more supressed than the other control methods on the row. Average weed coverage (% was found 56.09% in control (weedy, 24.66% in mowing, 11.05% in herbicide, 3.09% in black polyethylene, 2.78% in GEO-50, 0.87% GEO-100 and 0.76% JEO-150, respectively. As observed weed coverage (%, the similar result was found for weed number in black geotextile treatments.

  17. An Original Testing Apparatus for Rapid Pull-Out Test

    Aprialdi, D.


    Full Text Available Pull-out test is commonly used to investigate the pull-out behavior of geotextile reinforcement embedded in soil. It is also used by different authors to propose interface friction angles values. Unfortunately these works mainly deal with cyclic loadings with reference to seismic action, which are believed to be different to the load exposed to reinforced earthworks due to lateral impacts. Therefore an original rapid pull-out test apparatus is proposed in this study. This article assess the proposed test method in addressing the rapid pull-out response of a geotextile embedded in soil. The testing apparatus allows investigating shear velocities within the range of 0.1 to 1.2 m/s. This test method seems promising in addressing the response of soil-geotextile interfaces under dynamic loadings. Nevertheless, improvements concerning the testing apparatus are still required. The loading system could be modified to avoid oscillations and specific equipment should be added to increase the normal stress.

  18. Filtration of contaminated suspended solids for the treatment of surface water.

    Mulligan, Catherine N; Davarpanah, Neginmalak; Fukue, Masaharu; Inoue, Tomohiro


    As few technologies exist worldwide for the treatment of contaminated surface water, a new approach is currently under development consisting of an in situ water treatment system based on a floating filtration process for adsorbed contaminants such as heavy metals. Laboratory filtration tests were performed for the removal of contaminated suspended solids (SS) from surface water. SS, chemical oxygen demand (COD), and organic carbon (OC) were monitored. Of the four filters (two non-woven geotextiles, a woven geotextile and a sand filter) evaluated, filter 1 (a non-woven geotextile) was the most effective for removal % of the total suspended solids. The results demonstrated excellent efficiency by filter No. 1, for reducing turbidity by 93-98%, as well as SS by up to 98.9% and COD by 65-71% for three sites with initial turbidities of 70, 20, and 120 NTU, respectively. The level of heavy metal removal was 98.9% due the heavy metal content of the suspended solids (60 mg kg(-1) of Cu, 90 mg kg (-1) of Ni, 130 mg kg(-1) of Zn, 200 mg kg(-1) of Cr, and 80 mg kg(-1) of Pb). The development of this technology could potentially protect the public and aquatic plants and animals from dangerous contaminants such as heavy metals adsorbed onto the suspended solids.

  19. An innovative method to functionalize textiles for the remediation of polluted media

    Vandenbossche, Marianne [Unité Matériaux et Transformations (UMET), Ingénierie des Systèmes Polymères (ISP), CNRS-UMR 8207, ENSCL, Université Lille Nord de France, 59652 Villeneuve d’Ascq Cedex (France); Derozier, Dominique, E-mail: [Laboratoire de Physique des Lasers, Atomes et Molécules (PhLAM), UMR CNRS 8523, Université Lille Nord de France, 59655 Villeneuve d’Ascq Cedex (France); Casetta, Mathilde; Jimenez, Maude [Unité Matériaux et Transformations (UMET), Ingénierie des Systèmes Polymères (ISP), CNRS-UMR 8207, ENSCL, Université Lille Nord de France, 59652 Villeneuve d’Ascq Cedex (France); Bellayer, Séverine [Service Microsonde Électronique, ENSCL, Unité Matériaux et Transformations, Université Lille Nord de France, 59652 Villeneuve d’Ascq (France); Traisnel, Michel [Unité Matériaux et Transformations (UMET), Ingénierie des Systèmes Polymères (ISP), CNRS-UMR 8207, ENSCL, Université Lille Nord de France, 59652 Villeneuve d’Ascq Cedex (France)


    Highlights: • Knitted PET geotextiles were functionalized using an eco-friendly process. • Acrylic acid was grafted on PET geotextile fabric by excimer laser process. • The grafting optimization was carried out using experimental design technique. • The functionalized geotextile efficiency for the removal of Cu{sup 2+} was evaluated. - Abstract: A new, efficient and fast process was developed to coat poly(ethylene terephthalate) (PET) fabrics with acrylic acid (AA) and this novel eco-friendly material was designed to be used as a filtration medium for complexing heavy metals from aqueous media. PET is impregnated with acrylic acid, and directly polymerized using a KrF excimer laser. The conditions of irradiation were optimized using the experimental design technique: a 40 mm × 3.5 mm surface was irradiated per pulse, and 24 mJ/cm{sup 2} and 700 pulses were necessary to obtain a good coating without degrading the textile structure. For industrial purpose, these conditions were extended to treat larger surfaces (40 mm × 11.5 mm pulse) using a fluence of 24 mJ/cm{sup 2} and 700 pulses. Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) were carried out to characterize the functionalized surfaces. A thick coating, resistant to low-temperature-washing was obtained. Finally, the efficiency of this coated textile was evaluated with copper sulfate solutions: 0.131 mg copper was trapped per cm{sup 2} of PET, which is a promising result.

  20. Performance of pervious pavement parking bays storing rainwater in the north of Spain.

    Gomez-Ullate, E; Bayon, J R; Coupe, S; Castro-Fresno, D


    Pervious pavements are drainage techniques that improve urban water management in a sustainable manner. An experimental pervious pavement parking area has been constructed in the north of Spain (Santander), with the aim of harvesting good quality rainwater. Forty-five pervious pavement structures have been designed and constructed to measure stored water quantity and quality simultaneously. Ten of these structures are specifically constructed with different geotextile layers for improving water storage within the pavements. Following the confirmation in previous laboratory experiments that the geotextile influenced on water storage, two different geosynthetics (Inbitex and a One Way evaporation control membrane) and control pervious pavements with no geotextile layers were tested in the field. Weather conditions were monitored in order to find correlations with the water storage within the pervious pavement models tested. During one year of monitoring the three different pervious pavement types tested remained at their maximum storage capacity. The heavy rain events which occurred during the experimental period caused evaporation rates within the pervious pavements to be not significant, but allowed the researchers to observe certain trends in the water storage. Temperature was the most closely correlated weather factor with the level of the water stored within the pervious pavements tested.

  1. 柔性加筋土复合体力学性能试验%Experimental study of mechanical properties of flexible geosynthetic-reinforced soil complex

    胡幼常; 童金田; 刘胜军; 张文明


    In order to study the mechanical properties of flexible geosynthetic-reinforced soil complex,a series of unconfined compression tests were conducted in laboratory.The test samples were made up of sand reinforced respectively with nonwoven geotextile,geogrid,both geotextile and fiber,or both geogrid and fiber.Each sample varied in either the number of reinforcement inclusions or the density of sand.Based on the analysis of the test results,some conclusions are drawn as follows.1) There is an appropriate match among the geotextile strength,the reinforcement spacing and the sand density.The samples making according to such match have not only high compressive strengths but also large failure compressive strains.2) Sand reinforced with both geotextile and fiber has a higher compressive strength than that of one reinforced only by geotextile at the same conditions;but only a little difference between them while both the sand has a relatively low density and the reinforcement spacing is small.3) While the compressive strain is larger,the compressive strength of the geogrid-reinforced sand is much lower than that of geotextile-reinforced sand,which is perhaps due to the large difference between the geogrid and the sand in tensile stiffness resulting in sliding at the geogrid-soil interface.4) Compared with the geogrid-reinforced sand,the sample reinforced with both geogrid and fiber has a higher compressive strength at low compressive strain and a larger failure compressive strain due to the fiber inclusions.%为了研究柔性加筋土复合体的基本力学特性,分别对无纺土工布加筋砂、土工格栅加筋砂、"土工布+纤维"综合加筋砂和"土工格栅+纤维"综合加筋砂制作的多组试样完成了一系列组合工况下的无侧限抗压试验.得到以下主要结论:1)土工布的强度和加筋层间距应与砂的密度相匹配,此时,两者协同工作性最好,加筋砂土极限强度高,破坏应变大;2)相同情

  2. Integrating shotcrete walls into the natural landscape by application of 'Green Walls'

    Medl, Alexandra; Kikuta, Silvia


    Steep slopes resulting from major road infrastructure constructions are increasingly perceived as disagreeable disturbance in the landscape. Thus, a tool to consider landscape aspects and integrate these slopes into the natural environment is required. The challenge is to establish a sustainable vegetation layer despite of adverse circumstances such as inclinations of almost 90⁰, exposed position of slopes near streets and lack of soil and water supply. The objective of this study was to assess the performance of an innovative greening technology for vertical structures (shotcrete wall) in terms of vegetation development on varying plant substrates and geotextiles. The field experiment in Steinach am Brenner, Tyrol, Austria, included testing three plant substrates on basis of nearby rocky excavation material ('Innsbrucker Quarzphyllit', 'Bündnerschiefer' and 'Zentralgneis') combined with compost. Additionally, five geotextiles (geogrid (3x4 mm), geogrid (9x10 mm), coir net, coir mat, geo mat) were applied for evaluation. All test combinations were evaluated regarding vegetation cover and biomass production from 2015 to 2016. Analyses of chemical properties were conducted for all plant substrates. Results showed highest vegetation cover ratio on 'Bündnerschiefer' and 'Innsbrucker Quarzphyllit', which can be explained by the favorable mineral composition (nutrient storage capacity) and chemical properties of compost (lower values of electrical conductivity and C/N ratio). In conclusion, the use of 'Green Walls' filled with 'Bündnerschiefer' or 'Innsbrucker Quarzphyllit' plant substrate in combination with netlike geotextiles proved best, since geo grid and coir net turned out as most successful one year after installation. 'Green Walls' are promising in terms of establishing an optimal vegetation cover on vertical structures and are well suited for integrating shotcrete walls into the landscape. The use of local excavation material for greening purposes can be

  3. Stormwater Pollution Prevention Plan (SWPPP) for Coal Storage Area Stabilization Project

    Project and Design Engineering


    The scope of this project is to stabilize the abandoned coal storage area and redirect the storm water runoff from sanitary sewer system to the storm drain system. Currently, the existing storm water runoff is directed to a perimeter concrete drainage swale and collected in a containment basin. The collected water is then pumped to a treatment facility and after treatment, is discharged to the Y-12 sanitary sewer system. The existing drainage swale and collection basin along with silt fencing will be used during aggregate placement and grading to provide erosion and sediment control. Inlet protection will also be installed around existing structures during the storm water diversion construction. This project scope will include the installation of a non-woven geotextile fabric and compacted mineral aggregate base (paving optional) to stabilize the site. The geotextile specifications are provided on the vendor cut sheets in Appendix B. The installation of a storm water collection/retention area will also be installed on the southern side of the site in accordance with EPA Technical Guidance on Implementing the Stormwater Runoff Requirements for federal Projects under Section 438 of the Energy Independence and Security Act. The total area to be disturbed is approximately 2.5 acres. The order of activities for this Stormwater Pollution Prevention Plan (SWPPP) will be: (1) post notice of coverage (NOC) in a prominent display near entrance of the site; (2) install rain gauge on site or contact Y-12 Plant Shift Superintendent daily for Met tower rain gauge readings; (3) install stabilized construction exit on site; (4) install silt fencing along perimeter as indicated on the attached site plan; (5) regrade site; (6) install geotextile fabric and compacted mineral aggregate base; (7) install catch basin inlet protection where required; (8) excavate and lower existing catch basin tops, re-grade and asphalt to drain; and (9) when all disturbed areas are re-stabilized, remove

  4. Abiotic factors and trap design modulate the performance of traps used to monitor the plum curculio.

    Lamothe, Steve; Chouinard, Gérald; Vincent, Charles


    All published studies on effects of abiotic factors on plum curculio, Conotrachelus nenuphar (Hersbt), adults have taken a retrospective approach. Here, we present the results of experiments where factors and their levels were determined and controlled a priori. We compared the effectiveness of miniature pyramidal traps (45 by 20 by 20 cm) constructed of four kind of materials--wood, geotextile, nylon screening, and corrugated plastic--to monitor overwintered and summer adults of univoltine plum curculio. We also studied the effects of photoperiod, temperature, wind, and rain on pyramidal trap effectiveness. The experiments, which were replicated over time, were done in two controlled chambers that were divided into four sections, corresponding to simulated combinations (wind or no wind/rain or no rain). The temperatures tested (15, 20, and 25 degrees C) were randomly assigned in the chambers. During scotophase, geotextile traps captured significantly more overwintered and summer adults than traps made of other materials. The maximum proportion of captures (for overwintered and summer adults) during photophase was obtained at 25 degrees C, and it was significantly different than captures at 15 and 20 degrees C. During scotophase, significantly more overwintered and summer plum curculios were caught at 20 and 25 degrees C than at 15 degrees C. Our experiments demonstrated that geotextile is a good alternative to wooden pyramidal trap. Our results suggest that captures were higher 1) at night, 2) during warmer periods (20 and 25 degrees C), 3) when wind velocity was low and 4) during or shortly after rainfall, and 5) that photoperiod is a factor having an important predictive value for plum curculio captures.

  5. Analysis on the Long Term Effect of Trial Test Road Constructed on Batu Pahat Soft Clay (BPSC) at Recess UTHM

    Idrus, M. M. M.; Edayu, A. E.; Adnan, Z.; Ismail, B.


    The reinforcement used in soil for construction of roads on the soft clay is very important as it will determine the level of service of the road after it was built. Damage or defects on the road surface to be an indicator of the level of the road has dropped and shows the deformation of the road. For this research, an analysis has carried out on the long-term effect of trial test road constructed on Batu Pahat Soft Clay (BPSC) at RECESS UTHM. Through this research, the reinforcement using Rawell Geosynthetic Clay Liner (RGCL) was the best with the stability is 14964 N, a low flow is 2.69mm, stiffness modulus is 1766 MPa, the peak load is 739.4 N and a lower horizontal deformation which is 1.71 µm compared Woven Geotextile section and section without geotextile [1] [9]. In terms of deformation can be seen clearly from physical observations that section without geotextile suffered significant damage than others. Settlement of road can also be analyzed by a longitudinal section that plotted based on the result of leveling work. After that, settlements are more visible way on the right side of the road trial. Through lab tests conducted, it indicate that the coring samples obtained from sites of each section meets the specifications set by the Jabatan Kerja Raya (JKR) in terms of stability, flow and stiffness [1]. Through this study, a trial road built on soft soil can be used as a test site because of the uniqueness of these roads which has three different types of reinforcements.

  6. Flow Control and Design Assessment for Drainage System at McMurdo Station, Antarctica


    discontinuous and highly permeable , our estimate is that the weir will most likely fail by breaking apart instead of overturning. Thus, the sliding or shearing...sheet o One 12 × 9 ft sheet o One 20 × 36 in. sheet • Two spruce 2 × 8 in. rough sawn 2 ft planks • Nails to fasten planks together Rock weir...Knoxville 2003). • A flow net consisting of a piece of wood (two 2 × 8 in. nailed togeth- er edge to edge) with holes drilled in it and geotextile

  7. 浅谈土工合成材料的室内试验




  8. A Conceptual Study for the Autonomous Direct Forming of Lunar Regolith into Flexlock (Trademark) Geomats for Lunar Surface Operations

    Robertson, Luke B.; Hintze, Paul; OConnor, Gregory W.


    We describe the conceptual method of an autonomously operable Direct Forming machine that would consume regolith or regolith slag to mold intimately, interlinked elements in a continuous process. The resulting product, one to three meter wide geomats, would be deployed over commonly traversed areas to isolate the astronauts and equipment from underlying dust. The porous geotextile would provide areas for dust settling, thereby mitigating dust impingement on astronaut suits or surface structures. Because of their self-supporting yet flexible structure, these geomats could be assembled into shields and buttresses to protect lunar habitants from radiation, forming a "flexoskeleton" from in situ materials.

  9. Technical Textiles to Strut Their Stuff


    Will geotextiles soon be successfully creating fertile soil from arid desert landscapes? Will creative forms in mobility make it possible for even more people to be transported efficiently in the near future? Will textiles a few years from now be able to open up new habitats for humanity on distant planets? Will textiles be made safe against a spark that might sparkle into a conflagration in high-rise cities? The answers to these and many other exciting questions relating to visionary textiles production are all being researched in the field of technical textiles.

  10. The Effect of Various Fabric Parameters on the Sound Absorption Properties of Circular Knitted Spacer Fabrics

    Arzu Marmaralı


    Full Text Available Spacer fabrics which can be produced through weaving or nonwoven technique beside warp knitting and weft knitting processes, can be used for functional applications such as automotive textiles, medical textiles, geotextiles, sportswear, protective textiles and composites due to the possibility of using a variety of different materials, flexible product range and the three dimensional construction. Additionally they can also be used for sound absorption applications with different pore geometry. In this study, the effect of fabric parameters like material type, fabric thickness and surface structures on the sound absorption properties of circular knitted spacer fabrics was investigated and aimed to determine the optimum fabric parameters for better sound absorption.

  11. Durabilité des Géotextiles en Polypropylène

    Richaud, Emmanuel


    This thesis deals with the thermo-oxidative ageing of polypropylene geotextiles. The main objective was lifetime prediction from accelerated ageing tests using a non empirical method. Exposure tests with temperatures ranging from 50°C to 130°C under oxygen pressure ranging from 0.02 to 5.0 MPa were performed on stabilized and unstabilized PP samples. These latter contained a phosphite or a phenolic antioxidant in various concentrations. The study of the influence of an aqueous medium on accel...

  12. Long-term behaviour of a 13 m high reinforced steep soil slope. Paper presented at Euro Geo 1 Maastrict

    Vaslestad, Jan; Fjeldheim, Nils; Braaten, Anne; Johansen, Tor Helge


    In the summer of 1993 a 13 m high reinforced soil slope was built in the City of Lillehammer as part of the new road system constructed in conncection with the 1994 winter olympic games. The reinforced soil slope with an inclination of 60 degrees and a vegetated front was selected as an alternative to a reinforced concrete wall. This proved to be a very cost effective solution. The reinforcement used was a woven polyester geotextile with a characteristic short time tensile strength of 150 kN/...

  13. Multiscale analysis of the mechanical behavior of needle-punched nonwoven fabrics

    Martínez Hergueta, Francisca


    Los fieltros son una familia de materiales textiles constituidos por una red desordenada de fibras conectadas por medio de enlaces térmicos, químicos o mecánicos. Presentan menor rigidez y resistencia (al igual que un menor coste de procesado) que sus homólogos tejidos, pero mayor deformabilidad y capacidad de absorción de energía. Los fieltros se emplean en diversas aplicaciones en ingeniería tales como aislamiento térmico, geotextiles, láminas ignífugas, filtración y absorción de a...

  14. Multiscale analysis of the mechanical behavior of needle-punched nonwoven fabrics

    Martínez Hergueta, Francisca


    Los fieltros son una familia de materiales textiles constituidos por una red desordenada de fibras conectadas por medio de enlaces térmicos, químicos o mecánicos. Presentan menor rigidez y resistencia (al igual que un menor coste de procesado) que sus homólogos tejidos, pero mayor deformabilidad y capacidad de absorción de energía. Los fieltros se emplean en diversas aplicaciones en ingeniería tales como aislamiento térmico, geotextiles, láminas ignífugas, filtración y absorción de a...

  15. A distributed fiber optic sensor system for dike monitoring using Brillouin optical frequency domain analysis

    Nöther, Nils; Wosniok, Aleksander; Krebber, Katerina; Thiele, Elke


    We report on the development of a complete system for spatially resolved detection of critical soil displacement in river embankments. The system uses Brillouin frequency domain analysis (BOFDA) for distributed measurement of strain in silica optical fibers. Our development consists of the measurement unit, an adequate coating for the optical fibers and a technique to integrate the coated optical fibers into geotextiles as they are commonly used in dike construction. We present several laboratory and field tests that prove the capability of the system to detect areas of soil displacement as small as 2 meters. These are the first tests of truly distributed strain measurements on optical fibers embedded into geosynthetics.

  16. Final construction quality assurance report for the Y-12 Industrial Landfill V, Area 2, Oak Ridge, Tennessee

    Bessom, W.H. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States)


    Lockheed Martin Energy Systems (LMES) has finished construction of Area 2 of the Y-12 Plant Industrial Landfill (ILF-V), classified as a Class 2 Landfill. This final Construction Quality Assurance (CQA) Report provides documentation that Area 2 was constructed in substantial compliance with the Tennessee Department of Environment and Conservation (TDEC) approved design, as indicated and specified in the permit drawings, approved changes, and specifications. This report applies specifically to the Area 2 excavation, compacted clay soil liner, geomembrane liner, granular leachate collection layer, protective soil cover, and the leachate collection system. An ``As-Built`` survey was performed and is included. The drawings provide horizontal and vertical information for Area 2, the anchor trench, the leachate collection pipe, the temporary access road, and cross-sections of Area 2. This report provides documentation of the following items: the excavation activities of Area 2; the maximum recompacted coefficient of hydraulic conductivity or permeability of the soil is less than 1 {times} 10{sup {minus}7} centimeters per second (cm/sec); the total thickness of the compacted clay soil liner equals a minimum of 2 feet; a 40 mil impermeable geomembrane (polypropylene) flexible membrane liner (FML) and 16 oz. geotextile fabric was placed in direct contact with the compacted clay soil liner; a 12 inch granular leachate collection layer was installed and covered with a 8 oz. geotextile separation fabric; the installation of the leachate collection piping; and the two foot protective clay soil cover.

  17. Protozoa and metazoa relations to technological conditions of non-woven textile filters for wastewater treatment.

    Spychała, Marcin; Sowińska, Aleksandra; Starzyk, Justyna; Masłowski, Adam


    The objective of this study was a preliminary identification of basic groups of micro-organisms in the cross-sectional profile of geotextile filters for septic tank effluent (STE) treatment and their relations to technological conditions. Reactors with textile filters treating wastewater were investigated on a semi-technical scale. Filters were vertically situated and STE was filtered through them under hydrostatic pressure at a wastewater surface height of 7-20 cm. Filters were made of four layers of non-woven TS 20 geotextile of 0.9 mm thickness. Various groups of organisms were observed; the most abundant group comprised free-swimming and crawling ciliates, less abundant were stalked ciliates and the least numerous were nematodes. The individual counts of all groups of micro-organisms investigated during the study were variable according to time and space. The high abundance of Opercularia, a commonly observed genus of stalked ciliates, was related to the high efficiency of wastewater treatment and dissolved oxygen concentration of about 1.0 g/m3. Numbers of free-swimming and crawling ciliates had a tendency to decrease in relation to the depth of filter cross-sectional profile. The variability in counts of particular groups of organisms could be related to the local stress conditions. No correlation between identified organism count and total mass concentration in the cross-sectional filter profile was found.

  18. Experiment on Underdrain Pipe Filter in Yinbei Irrigation District in Ningxia Autonomous Region%宁夏银北灌区暗管排水反滤层试验研究



    According to the soil properties and the layoutof the underdrain pipes in Yinbei Irrigation District, 4groups of representative soil samples were selected in Situ,hereafter, 8 groups of filtration examinations which corre-sponded short-filer geotextile, machine-made geotextile, andknitted geotextile' were done, the analysis on the result ofexaminations would provid a scientific basis for selecting theunderdrain pipe filters reasonally.%根据宁夏银北灌区的土壤特性和排水暗管布置形式及位置,在现场选取了三组具有一定代表性的土样,分别对短纤针刺土工织物、机织土工织物和编织土工织物进行了八组暗管排水反滤层试验。并对试验成果进行了分析,为合理选择暗管排水滤层提供了科学依据。

  19. Textile protection of snow and ice: Measured and simulated effects on the energy- and mass balance

    Olefs, Marc; Lehning, Michael


    Measurements and simulations of the energy fluxes and mass changes of an artificially covered snow and ice surface (geotextile material) and a reference plot within an Austrian glacier ski resort are presented and compared. A modified version of the snow cover model SNOWPACK is used to successfully reproduce the artificially compacted and the additionally covered snow cover in a physically based way. Supplementary measurements of crucial material properties of the 0.0045 m thin geotextile serve as model input as well. Results indicate that the shortwave reflectivity of the covers is responsible for half the performance (47%). Thermal insulation of the material (14%) and a negative latent heat flux due to evaporation of precipitation from the cover surface (10%) have almost the same contribution. An assumed layer of air between the cover and the snow and ice surface (thickness 0.075 m to 0.12 m) adds the rest, which is at the upper limit of observations and may therefore also compensate for model errors. This generally explains the high performance of the method in glacier skiing resorts and, most importantly, an altitude dependant application limit of the method: the method becomes less effective at lower altitudes, where sensible heat fluxes become more important compared to short wave radiation.

  20. Bio-tarp alternative daily cover prototypes for methane oxidation atop open landfill cells.

    Adams, Bryn L; Besnard, Fabien; Bogner, Jean; Hilger, Helene


    Final landfill covers are highly engineered to prevent methane release into the atmosphere. However, methane production begins soon after waste placement and is an unaddressed source of emissions. The methane oxidation capacity of methanotrophs embedded in a "bio-tarp" was investigated as a means to mitigate methane release from open landfill cells. The bio-tarp would also serve as an alternative daily cover during routine landfill operation. Evaluations of nine synthetic geotextiles identified two that would likely be suitable bio-tarp components. Pilot tarp prototypes were tested in continuous flow systems simulating landfill gas conditions. Multilayered bio-tarp prototypes consisting of alternating layers of the two geotextiles were found to remove 16% of the methane flowing through the bio-tarp. The addition of landfill cover soil, compost, or shale amendments to the bio-tarp increased the methane removal up to 32%. With evidence of methane removal in a laboratory bioreactor, prototypes were evaluated at a local landfill using flux chambers installed atop intermediate cover at a landfill. The multilayered bio-tarp and amended bio-tarp configurations were all found to decrease landfill methane flux; however, the performance efficacy of bio-tarps was not significantly different from controls without methanotrophs. Because highly variable methane fluxes at the field site likely confounded the test results, repeat field testing is recommended under more controlled flux conditions.

  1. Smart technical textiles with integrated POF sensors

    Krebber, Katerina; Lenke, Philipp; Liehr, Sascha; Witt, Jens; Schukar, Marcus


    Fiber optic sensors based on polymer optical fibers (POF) take advantage of the high elasticity and high break-down strain of POF. Because of their outstanding elastic properties, POF are well suited for integration into technical textiles like geotextiles and medical textiles. Smart textiles with incorporated POF sensors, able to sense various mechanical and physical quantities, can be realized. The integration of POF as a sensor into geotextiles for monitoring of displacement of soil is very attractive since POF can be used for distributed strain measurement of strain values of more than 40 %. An online monitoring of critical mechanical deformations of geotechnical structures like dikes, dams, slopes, embankments as well as of masonry structures can be ensured. Medical textiles that incorporate POF sensors can control vital physiological parameters like respiratory movement and can be used for wearable health monitoring of patients requiring a continuous medical assistance and treatment. The biocompatibility of POF is an important criterion for selecting POF as a medical sensor. The paper shows selected examples of using POF sensors for the mentioned monitoring purposes.

  2. 土工合成材料在固化土海上围堤工程中的综合应用%Comprehensive application of geosynthetics in solidified soil sea dike projects

    刘爱民; 梁爱华


    In combination with the actual project, the application of geosynthetics are introduced. The results show that woven nonwoven geotextile, nonwoven geotextile, filling bags and other geosynthetics can be used to solidify soil sea dike project, and they play the role of drainaging, filtration, separation, protection and so on. The key technical problems of mud embankment is solved. The construction of water transportation is promoted. They are worthy of further application.%结合现场实际工程,对土工合成材料的应用情况进行了介绍。结果表明:机织无纺布、无纺土工布、土工充填袋等土工合成材料均可用于固化土海上围堤工程,起到相应的排水、反滤、隔离、防护等作用,解决了利用淤泥筑堤的关键技术难题,对我国水运工程建设起到了很大的推动作用,值得进一步推广应用。

  3. 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

    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)


    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)




    Full Text Available The most significant factor that influencing the design thickness of a flexible pavement overlay is rebound deformation from repeated load application and subgrade support values . It is essential to stabilize and reinforce the poor soils to bear the traffic intensity or truck loading. Different types of materials are provided with stabilization techniques to achieve suitable performance and to reduce maintenance costs and also to provide required service life for the subgrade embankments. In the present study, the effect of geo-textile as a reinforcement in the sub grade embankment is verified by conducting cyclic plate load tests. Locally available soil is mixed with optimum of fly ash and then this mixer is stabilized with optimum of CaCl2 for the construction of sub grade embankment with and with out reinforcement. Compaction properties and C.B.R values are determined for the locally available soil and categorized as CH soil as per IS classification, fly ash, fly ash - CaCl2 mix with the CH soil. The introduction of geo-textile has been reduced the deformation and increased the load carrying capacity as was revealed by cyclic plate load tests.

  5. Comparison of Effects of Using Geosynthetics and Lime Stabilization to Increase Bearing Capacity of Unpaved Road Subgrade

    Erhan Burak Pancar


    Full Text Available So many soil improvement methods have been developed in order to increase bearing capacity of superstructure of the road to be constructed on the soft clayey road base soils, decrease settlements, and increase other strength specifications (CBR, k, MR values, etc.. In this paper, lime stabilization of clayey road base soil with high water content and its improvement with geosynthetics (geocell + geotextile reinforcement and comparisons of these two different improvement methods were made. For this purpose, plate loading experimental comparisons of clayey soil, which had high water content by 10% increasing the optimum water content, were made after it was improved with lime at the rates of 3, 6, and 12%, geotextile reinforcement, geocell reinforcement, geosynthetics reinforcement, and geosynthetics reinforcement + lime stabilization at various rates. It was understood that these improvement methods will not yield sufficient results on clayey soils with high water content on their own, and method of improvement with lime and then reinforcement with geosynthetics yields better results on these types of soils. Only one improvement state among ten different states examined in this study gave the sufficient results for the soil to be used for unpaved roads.

  6. 巴布亚新几内亚Mendi-Kandep公路软基处置设计与实现%Soft Foundation Disposal Design and Implementation of Papua New Guinea Mendi-Kandep Highway

    刘平; 刘长有


    以巴布亚新几内亚Mendi-Kandep公路为背景,介绍了在热带多雨地区资源匮乏的情况下公路软基处置的换填垫层法和土工织物加固法结合使用的效果,说明这种方法的有效性和经济性,同时通过现场试验确定了土工织物的布设及受力特点,并对垫层尺寸的计算方法进行了说明。%Taking the Papua New Guinea Mendi-Kandep highway as background, this paper introduces the effect of the combination of replacement cushion method and the geotextile reinforcement method for highway soft foundation disposal in the tropical rainy regions with scarce resources, indicates the effectiveness and efficiency of this approach, at the same time determines the layout and mechanical characteristics of geotextile through field tests, and describes the cushion size and calculation methods.

  7. Strain gage installation and survivability on geosynthetics used in flexible pavements

    Brooks, Jeremy A.

    The use of foil type strain gages on geosynthetics is poorly documented. In addition, very few individuals are versed in proper installation techniques or calibration methods. Due to the limited number of knowledgeable technicians there is no information regarding the susceptibility of theses gages to errors in installation by inexperienced installers. Also lacking in the documentation related to the use of foil type strain gages on geosynthetics is the survivability of the gages in field conditions. This research documented procedures for installation, calibration, and survivability used by the project team to instruments a full scale field installation in Marked Tree, AR. This research also addressed sensitivity to installation errors on both geotextile and geogrid. To document the process of gage installation an experienced technician, Mr. Joe Ables, formerly of the UASCE Waterways Experiment Station, was consulted. His techniques were combined with those discovered in related literature and those developed by the research team to develop processes that were adaptable to multiple gage geometries and parent geosynthetics. These processes were described and documented in a step by step manner with accompanying photographs, which should allow virtually anyone with basic electronics knowledge to install these gages properly. Calibration of the various geosynthetic / strain gage combinations was completed using wide width tensile testing on multiple samples of each material. The tensile testing process was documented and analyzed using digital photography to analyze strain on the strain gage itself. Calibration factors for each geosynthtics used in the full scale field testing were developed. In addition, the process was thoroughly documented to allow future researchers to calibrate additional strain gage and geosynthetic combinations. The sensitivity of the strain gages to installation errors was analyzed using wide width tensile testing and digital photography to

  8. Road runoff management using over-the-shoulder infiltration: real-scale experimentation.

    Piguet, P; Parriaux, A; Bensimon, M


    A new management policy regarding road runoff was proposed in 2002 by the Swiss Federal Office for the Environment (FOEN). This new concept is based on the diffuse infiltration of road runoff into embankment slopes, where soils will filter particles and contaminants. The shoulder lying between road surface and infiltration slopes must be impervious in order to maximise the amount of water reaching the slope and avoid losses in the road structure. The implementation of this new concept should lower the impact of roads on the environment, improve aquifer recharge and reduce construction costs. The Swiss Federal Road Office (FedRO) decided to carry out real-scale investigations regarding this new policy and thus commissioned the GEOLEP to design, build, and test 5 different shoulder structures. This paper presents the results of a 2-years survey of infiltration processes in these shoulders to establish the best performing structure. The first three shoulders were overlaid with 5 cm of gravel mixed with humus, gravel mixed with clay, and seeded with lawn, respectively. The latter two had impervious layers located 26 cm deep: the road bituminous basement (road base) was prolonged and coated with bitumen in the first case, and a sodic-bentonite geotextile was used in the second. Both were covered with gravel. All shoulders were equipped with basal collecting devices that measured hydraulic fluxes seeping through the shoulders. In total, 112 natural precipitations and 3 artificial events were monitored. Artificial events mimicked known transitory regimes (thunderstorms) or were performed with constant regime. The goal was to effectively assess infiltration processes in shoulders. Results showed that shoulders made of gravel and humus or lawn were highly ineffective (only 30 to 40% of runoff is conducted to the infiltration slope). Gravel and clay was more efficient with a proportion of approximately 60%. The shoulder with prolonged road base showed similar results since

  9. 影响GCL防渗性能因素分析%Factors for anti-seepage performance of GCL

    谢世平; 何顺辉; 张健


    钠基膨润土防水毯(以下简称GCL)在国内已应用20多年,但GCL的生产和使用存在一些疏忽,影响了GCL的防渗性能和使用效果。通过对编织布、膨润土粒径、施工搭接,以及测试方法等方面存在的问题进行分析,阐明这些因素对GCL防渗性能以及测试的影响。研究结果表明:圆织编织布不宜用于防渗要求严格的GCL的生产;以GCL为主防渗层的工程,应该使用粉末型GCL;GCL检测应将由于编织布不平整导致的缺土现象列入检测指标;施工中处理GCL搭接区域阻断无纺布导渗作用的措施应有效可靠。%The sodium bentonite geosynthetic clay liner (hereinafter short for GCL) has been applied for over twenty years in China. However, there are some important negligences in the production and applications of GCL, and its anti-seepage performance is affected. The factors such as type of woven geotextile, particle size of bentonite, overlapping in construction as well as some issues in the test methods are analyzed, and their effects on the test methods and anti-seepage performance of GCL are clarified. The results show that the circular woven geotextile is not suitable for producing GCL. The right kinds of GCL should be selected according to the project. For example, while using GCL as the main impermeable layer, powdered GCL should be chosen. GCL construction should strictly follow the installation guide, handling the overlapping area should be standardized and reliable, and the most crucial of overlapping is to stop the drainage effect of nonwoven geotextile. The dead zone of the relevant standards should be improved.

  10. Determination of water absorption and water holding capacities of different soil mixtures with MINIDRAIN system to enhance the plant growth

    Sudan Acharya, Madhu; Rauchecker, Markus; Wu, Wei


    Soil water holding capacity is the amount of water that a given soil can hold against the force of gravity. Soil texture and organic matter are the key components that determine soil water holding capacity. Soils with smaller particle sizes, such as silt and clay have larger surface area can hold more water compared to sand which has large particle sizes which results in smaller surface area. A study report showed that 1% increase in soil humus will result in a 4% increase in stored soil water (Morris, 2004) and 1 part humus holds 4 parts of water (Wheeler and Ward, 1998). Therefore, the more humus that can be added to the soil, the greater the water holding capacity of the soil. As the level of organic matter increases in a soil, the water holding capacity also increases due to the affinity of organic matter for water. The water holding capacity of the soil is determined by the amount of water held in the soil sample vs. the dry weight of the sample. MINIDRAIN is a patented system made of geo-fabric (fleece) or combination of geosynthetics and humus. MINIDRAIN and vegetation nets developed by the company ÖKO-TEX (Linz, Austria) will improve the distribution of water and air in the soils, increase the growth of vegetation and reduce the soil erosion. Depending on the physical configuration, there are four different combinations of MINIDRAIN systems developed by ÖKO-TEX. a) Geotextile (fleece) strips of different sizes (e.g. 5x10x250 mm) b) Net formed strips (drainage nets) of different sizes c) Multilayer geotextile mats with humus, seeds or compost of different sizes (e.g. 10x30x200 mm) d) Multilayer geotextile net formed mats with humus, seeds or compost This paper describes the experimental results of the water absorption and water holding capacity of different forms of MINIDRAIN under different soil mixes. In this experiment, potting soil, coarse sand and LECA (Light weight clay aggregates) balls are mixed with different proportion of MINIDRAIN systems and

  11. Structures of subgrade/pavement and construction techniques for the Taklimakan Desert Highway

    李志农; 金昌宁


    With lots of indoor and outdoor experiments, several key technical issues in construc-tion of the Desert Highway have been solved satisfactorily, on the basis of great achievements ofthe studies in respects of dry compaction on sand base, design parameters, structure combinationof subgrade and pavement, stabilization analysis of sand base strengthened with geotextile and acomplete set of construction techniques. It is the first time the achievements of the study weresuccessfully applied in the Taklimakan Desert where the natural condition is extremely harsh. Ithas been proved that it is economic and reasonable with reliable techniques and simple construc-tion methods. The Desert Highway constructed with the achievements is the first-grade highwayrunning through huge migratory desert for long distance in the world.

  12. Spanish experience in the use of synthetic geo membranes for hydraulic works; Experiencia espanola en el uso de geomembranas sinteticas en obras hidraulicas

    Blanco Fernandez, M.; Leiro Lopez, A.


    The Spanish institution Centro de Estudios y Experimentacion de Obras Publicas (CEDEX) has studied for decades the behaviour of geosynthetic products, specially the polymeric geo synthetic barriers used as waterproofing systems of different hydraulic works, mainly in reservoirs. Both in geotextiles or related products and in geomembranes, initial characteristics are determined; besides of that, periodic controls along the service life are performers in geomembranes. The monitoring of more than two hundred hydraulic structure hydraulic structures requires technical inspection, taking samples and replacing them, experimental tests and recommendations, with the purpose of increasing security and durability in hydraulic structures. Because of that, the Spanish experience in this field of technology is presented along this paper. (Author)

  13. Understanding the factors influencing the removal of heavy metals in urban stormwater runoff.

    Maniquiz-Redillas, Marla C; Kim, Lee-Hyung


    In this research, an infiltration trench equipped with an extensive pretreatment and filter bed consisting of woodchip, sand and gravel was utilized as a low impact development technique to manage stormwater runoff from a highly impervious road with particular emphasis on heavy metal removal. Findings revealed that the major factors influencing the removal of heavy metals were the concentration of the particulate matters and heavy metals in runoff, runoff volume and flow rates. The reduction of heavy metals was enhanced by sedimentation of particulates through pretreatment. Fine particles (design considerations. Sediment was most highly attached on the surface area of woodchip than to other filter media like sand, gravel and geotextile. It is suggested that maintenance must be performed after the end of the winter season wherein high sediment rate was observed to maintain the efficiency of the treatment system.

  14. Design and Performance of an Enhanced Bioremediation Pilot Test in a Tidal Wetland Seep, West Branch Canal Creek, Aberdeen Proving Ground, Maryland

    Majcher, Emily H.; Lorah, Michelle M.; Phelan, Daniel J.; McGinty, Angela L.


    Because of a lack of available in situ remediation methods for sensitive wetland environments where contaminated groundwater discharges, the U.S. Geological Survey, in cooperation with the U.S. Army Garrison, Aberdeen Proving Ground, Maryland, conceived, designed, and pilot tested a permeable reactive mat that can be placed horizontally at the groundwater/surface-water interface. Development of the reactive mat was part of an enhanced bioremediation study in a tidal wetland area along West Branch Canal Creek at Aberdeen Proving Ground, where localized areas of preferential discharge (seeps) transport groundwater contaminated with carbon tetrachloride, chloroform, tetrachloroethene, trichloroethene, and 1,1,2,2-tetrachloroethane from the Canal Creek aquifer to land surface. The reactive mat consisted of a mixture of commercially available organic- and nutrient-rich peat and compost that was bioaugmented with a dechlorinating microbial consortium, WBC-2, developed for this study. Due to elevated chlorinated methane concentrations in the pilot test site, a layer of zero-valent iron mixed with the peat and compost was added at the base of the reactive mat to promote simultaneous abiotic and biotic degradation. The reactive mat for the pilot test area was designed to optimize chlorinated volatile organic compound degradation efficiency without altering the geotechnical and hydraulic characteristics, or creating undesirable water quality in the surrounding wetland area, which is referred to in this report as achieving geotechnical, hydraulic, and water-quality compatibility. Optimization of degradation efficiency was achieved through the selection of a sustainable organic reactive matrix, electron donor, and bioaugmentation method. Consideration of geotechnical compatibility through design calculations of bearing capacity, settlement, and geotextile selection showed that a 2- to 3-feet tolerable thickness of the mat was possible, with 0.17 feet settlement predicted for

  15. Influence of Repeated Loading and Geosynthetic Reinforcement on Base Course Thickness over Soft Soil

    Slamet Widodo


    Full Text Available Vehicle wheels at surface of pavement will pass through it many times. Pavement or base course over soft soil always needs a reinforcement.  Influence of repeated loading to thickness of base course and base course reinforced by geosynthetic is presented. Several existing methods as Giroud-Han, USA Corps of Engineers and DuPont Typar method respectively to calculate thickness of base course over soft soil using reinforcement material either geotextile or geogrid is presented and the influence of repeated loading will be compared. Results from calculation and analysis indicate that Giroud-Han method gives thickness of base course higher than other methods when CBR values of subgrade at least 2 %.


    Mudimby Andal


    Full Text Available This paper presents the influence of partial replacement of bentonite by silica fume which is used in the manufacture of Geosynthetic Clay Liner (GCL. Geosynthetic Clay Liners consist bentonite (Sodium Based sandwiched between two geotextile. Benotinite, having low permeability imparts better hydraulic performance to the GCL to act as liner. In this investigation, an attempt has been made to study the hydraulic conductivity of GCL with modified Bentonite. The bentonite is partially replaced by silica fume, a waste product of ferroalloy industries. Silica fume reduces the cracking characteristics of bentonite on desiccation. The replacement levels varied from 0% to 50% at a gradual increment of 5%. The test results indicated that partial replacement of bentonite by silica fume did not affected the permeability of bentonite even at 30%. Beyond 45% replacement levels the bentonite- silica fume mixtures showed increased permeability. This increased permeability also well within permeability limits of liners 1×10-9 m/sec.

  17. Selected Problems Of Noninvasive Ooze Dredging In The Protected Areas Of Port Docks

    Abramowicz-Gerigk Teresa


    Full Text Available The paper presents the analysis of the ooze dredging concepts in the protected areas of harbour docks. The proposed method and system for ooze dredging are dedicated to all types of seabed protection, but the main concern are the geotextile mattresses, not resistant to mechanical damages. Due to the large seabed areas covered with this type of protection the effective method of noninvasive ooze dredging should be based on the use of a technical vessel for underwater works. The result of the analysis is the concept of the method and system for ooze dredging including in particular the mechanism for the automatic holding of the suction-dredge head in the proper distance from the seabed protection surface - the leading wheel truck and buoyancy-ballast system.


    D. Koteswara Rao,


    Full Text Available Majority of the population in India are living in costal corridor, where the existing soils are weak and more deformative. It is becoming a great challenge for the civil engineers to design suitable foundation for the structures in these regions. The effect of GBFS, lime and geotextile as reinforcement & separator on the marine clay foundation soil bed in field has been investigated. A test track of 8m long and 2m wide was laid in the field for testing the treated and untreated conditions of the marine clay foundation soil beds. The ultimate load carrying capacity of the test tracks for untreated and treated conditions have been studied and also the degree of compaction of the test tract was found.

  19. Experimental analysis and modeling of a stormwater perlite filter.

    Gironás, Jorge; Adriasola, José M; Fernández, Bonifacio


    This paper presents the study of a mixed porous media composed of expanded perlite and a nonwoven needle-punched geotextile used to reduce the suspended solids load and concentration in urban runoff. Laboratory procedures were designed to quantify the suspended solids removal efficiency and variation in time of filtration rate. Different grain-size distributions of expanded perlite, diverse suspended solids concentrations, and different hydraulic and geometric conditions were tested to determine the most effective filter media. A dimensionless parameter, termed Global Performance Index (GPI), was developed to reach this objective. Measured data were also used to build a dimensional and a regression model to represent the performance of the filter media mathematically. The theory, derivation, and performance of both models are presented and compared with an existent empirical model. The dimensional model better reproduces the observations, becoming a useful tool for the design, operation, and evaluation of commercial porous media filters.

  20. Influências físicas sobre características químicas na compostagem da fracção sólida de chorume de bovinos leiteiros Influence of dairy cattle slurry solid fraction physical characteristics on chemical characteristics of composts

    L. M. Brito


    Full Text Available As características físicas das pilhas de compostagem da fracção sólida do chorume (FSC são responsáveis pela criação de condições aeróbias ou anaeróbias e determinam a actividade metabólica e a temperatura no interior das pilhas. Aqui, a FSC de duas explorações leiteiras foi compostada em pilhas com e sem volteio, com o volume de 5 m³ no interior de um túnel, cobertas com um filme de polietileno, ou descobertas, e com o volume de 15 m³ no exterior do túnel, cobertas com um filme de polietileno, ou com uma tela geotextil que não permite a infiltração de água mas permite as trocas gasosas. As pilhas cobertas com tela geotextil e as pilhas descobertas atingiram temperaturas mais elevadas na fase termófila da compostagem em comparação com as pilhas cobertas com polietileno porque beneficia-ram com a difusão do oxigénio. Quando cobertas com polietileno as temperaturas mais baixas registaram-se nas pilhas com a FSC que possuía inicialmente maior teor de humidade. As características físicas como a temperatura, humidade e arejamento das pilhas foram comparadas periodicamente durante a compostagem com características químicas dos compostados, designadamente, pH, condutividade eléctrica, matéria orgânica, azoto Kjeldahl e razão C/N. Relacionaramse as perdas de matéria orgânica durante a compostagem com a concentração de N no material compostado, verificando-se que a FSC pode ser compostada com perdas mínimas de N em pilhas estáticas com um número reduzido de volteios.The physical characteristics of the solid fraction from slurry are responsible for the creation of aerobic or anaerobic conditions and therefore for the metabolic activity and the temperature inside the composting pile. Here, the dairy cattle slurry solids from two different farms located at the NW Portugal was composted with and without turning the pile, in piles with 5 m³ inside an unheated greenhouse covered with a polyethylene film or not


    D. Koteswara Rao,


    Full Text Available India being peninsular country has large area coming under coastal region and also it has been the habitat for considerable percentage of population. The marine clays are generally found in the coastal region of West Bengal, Orissa, Andhra Pradesh, Tamilnadu, Kerala, Karnataka, Maharashtra and some parts of Gujarat. Marine or soft clays exists in these region are weak and deformative in nature. The present study deals with the strength characteristics of the marine clay collected from Kakinada Sea Port Ltd, Kakinada, A.P, India. The effect of lime on the strength characteristics of marine clay are studied in this investigation along with the reinforcement effect using geotextile as reinforcement and separator for the foundation soil bed.


    M. Andal


    Full Text Available This paper presents the influence of partial replacement of bentonite by silica fume which is used in the manufacture of Geosynthetic Clay Liner (GCL. Geosynthetic Clay Liners consist bentonite (Sodium Based sandwiched between two geotextile. Benotinite, having low permeability imparts better hydraulic performance to the GCL to act as liner. In this investigation, an attempt has been made to study the hydraulic conductivity of GCL with modified Bentonite. The bentonite is partially replaced by silica fume, a waste product of ferroalloy industries. Silica fume reduces the cracking characteristics of bentonite on desiccation. The replacement levels varied from 0% to 50% at a gradual increment of 5%. The test results indicated that partial replacement of bentonite by silica fume did not affected the permeability of bentonite even at 30%. Beyond 45% replacement levels the bentonite- silica fume mixtures showed increased permeability. This increased permeability also well within permeability limits of liners 1×10-9m/sec.

  3. Biological regeneration of ferric (Fe3+) solution during desulphurisation of gaseous streams: effect of nutrients and support material.

    Mulopo, Jean; Schaefer, L


    This paper evaluates the biological regeneration of ferric Fe3+ solution during desulphurisation of gaseous streams. Hydrogen sulphide (H2S) is absorbed into aqueous ferric sulphate solution and oxidised to elemental sulphur, while ferric ions Fe3+ are reduced to ferrous ions Fe2+. During the industrial regeneration of Fe3+, nutrients and trace minerals usually provided in a laboratory setup are not present and this depletion of nutrients may have a negative impact on the bacteria responsible for ferrous iron oxidation and may probably affect the oxidation rate. In this study, the effect of nutrients and trace minerals on ferrous iron oxidation have been investigated and the results showed that the presence of nutrients and trace minerals affects the efficiency of bacterial Fe2+oxidation. The scanning electron microscopy analysis of the geotextile support material was also conducted and the results showed that the iron precipitate deposits appear to play a direct role on the bacterial biofilm formation.

  4. The cost and effectiveness of solids thickening technologies for treating backwash and recovering nutrients from intensive aquaculture systems.

    Sharrer, Mark; Rishel, Kata; Taylor, Amanda; Vinci, Brian J; Summerfelt, Steven T


    The cost and effectiveness of three solids thickening processes, i.e., gravity thickening settlers (GTS), inclined belt filters (IBF), geotextile bag filters (GBF), were individually evaluated with the biosolids backwash produced in intensive aquaculture systems equipped with microscreen drum filters and radial-flow settlers. The IBF produced the cleanest discharge and highest treatment efficiencies, likely reflecting the rapid efficiency with which solids are separated from wastewater. The GBF was the least effective process, i.e., GBF leachate contained the highest concentrations of TP, TN, and cBOD. However, GBF was most effective for sludge volume reduction. Capital cost estimates for an IBF were more than twice that of GTS and GBF of similar treatment capacity. The GTS had the lowest capital and annual operating cost estimates. The estimated annual operating cost of the GBF was orders of magnitude higher than the IBF and GTS, due to the high cost to replace bags.

  5. Laboratory analysis of a system for catchment, pre-treatment and treatment (SCPT) of runoff from impervious pavements.

    Fernández-Barrera, A H; Rodriguez-Hernandez, J; Castro-Fresno, D; Vega-Zamanillo, A


    This article reports the development and construction of a 1:1 scale laboratory prototype of a System for Catchment, Pre-treatment and Treatment (SCPT) of runoff polluted by contaminants washed from impervious pavements. The concept of the SCPT is an online system with an up-flow filter. The filter is composed of geotextile layers and limestone. The laboratory tests carried out were focused on determining the SCPT prototype behaviour under different working conditions. The variables studied were: inflow, pollutant loads and filtration system configuration. The results show that the system designed has a high capacity for treatment of solids and oil, with an average efficiency of 85% and 97% respectively. Moreover, the regression equations of the treatment efficiency were determined for each of the pollutants studied, for different inflow conditions and pollution loads.

  6. Prevention from Dike Failure by Emergency Flood Control Measures

    Koppe Baerbel


    Full Text Available The risk of failure of a flood protection system must always be taken into account. During flooding events, appropriate interim protection systems must be at hand and ready to be deployed to support weak and overloaded structures. Usually sandbags, eventually in combination with fascines and geotextiles, are in use to defend endangered dike stretches in case of emergency. Sandbags offer highly flexible employment, however the enormous personal, material and time consuming efforts required for installation and dismantling are problematic. Therefore, more effective constructions for emergency flood control are needed. Within the research projects HWS-Mobile, DeichSCHUTZ, and DeichKADE different constructions based on the use of flexible membranes have been developed or are in development to ensure easy and effective countermeasures to secure dike stretches, which are in risk of breakage. Successful applications of the developed systems have taken place during the catastrophic flood event at the river Elbe in Northern Germany in 2013.

  7. Conference Proceedings: World Wise 99 -- Conference on sustainable infrastructure: emerging technologies for the new millennium



    Energy conservation and sustainable development through emerging technologies was the focus of this third biennial conference of the Manitoba Heavy Construction Association. Papers presented discussed a wide range of topics including a few pertaining to developments in the livestock industry in Manitoba, a substantial number of papers involving road and bridge construction and management, paving and concrete building products, aqueduct and trenchless sewer rehabilitation, and cathodic protection of water mains. The majority of the speakers discussed topics related to sustainable development and environmental protection such as stormceptor hydrology, chemical contamination in site remediation projects, optimization of wastewater stabilization ponds, recycling organic residuals and land rehabilitation, harnessing the energy of ocean waves, alternative energy sources, and the beneficial re-use of glass, rubber and geotextiles in road construction. Commercializing new technology was the subject of an extended panel discussion.

  8. Design and construction of an experimental pervious paved parking area to harvest reusable rainwater.

    Gomez-Ullate, E; Novo, A V; Bayon, J R; Hernandez, Jorge R; Castro-Fresno, Daniel


    Pervious pavements are sustainable urban drainage systems already known as rainwater infiltration techniques which reduce runoff formation and diffuse pollution in cities. The present research is focused on the design and construction of an experimental parking area, composed of 45 pervious pavement parking bays. Every pervious pavement was experimentally designed to store rainwater and measure the levels of the stored water and its quality over time. Six different pervious surfaces are combined with four different geotextiles in order to test which materials respond better to the good quality of rainwater storage over time and under the specific weather conditions of the north of Spain. The aim of this research was to obtain a good performance of pervious pavements that offered simultaneously a positive urban service and helped to harvest rainwater with a good quality to be used for non potable demands.

  9. Modelling of the flow in the interface of a composite liner at the bottom of a municipal waste landfill; Modelisation des ecoulements dans les interfaces des barrieres d'etancheite composites des installations de stockage de dechets

    Cartaud, F


    Composite liner at the bottom of waste landfill is based, in France, on a geo-membrane overlapping a compacted clay liner. Defects exist in geo-membranes and leachates, provided by water percolation through the waste, then flow in the interface between the two components of the lining system. The present work consisted in analysis, quantification and modelling of the leakage process in the interface. The experimental study has been carried out on a one-meter scale device in laboratory and allowed to assess the role of normal stress on the flow rate in interface. The case where a geo-textile is present beneath the geo-membrane has been also studied. The modelling allows to take into account more accurately the geometry of the interface and ensures a better quantification of leachate flow rates than using existing methods. (author)

  10. Enviro-geotechnical considerations in waste containment system design and analysis

    Fang, H.Y.; Daniels, J.L.; Inyang, H.I. [Univ. of Massachusetts, Lowell, MA (United States)


    The effectiveness of waste control facilities hinges on careful evaluation of the overall planning, analysis and design of the entire system prior to construction. At present, most work is focused on the waste controlling system itself, with little attention given to the local environmental factors surrounding the facility sites. Containment materials including geomembranes, geotextiles and clay amended soils have received intense scrutiny. This paper, however, focuses on three relatively important issues relating to the characterization of the surrounding geomedia. Leakage through naturally occurring low-permeability soil layers, shrinkages swelling, cracking and effects of dynamic loads on system components are often responsible for a waste containment breach. In this paper, these mechanisms and their synergistic effects are explained in terms of the particle energy field theory. It is hoped that this additional information may assist the designer to be aware or take precaution to design safer future waste control facilities.

  11. Justification of application of new types of fastening of slopes of hydraulic engineering constructions

    Smyvalov Anatoly


    Full Text Available The article represents the analysis of various types of fastenings of the soil slopes which have found broad application in the hydrotechnical construction practice for the last 10-15 years. It is noted that, generally, new types of fastenings represent composite materials made of concrete, metal and polymers. Experience shows that producers of the construction materials used in bank protection designs seek to recommend them for the solution of a wide range of tasks, at the same time it isn’t always founded. The authors, on the basis of the analysis of experience with the types of fastenings and also modern domestic and foreign recommendations about their design and construction, offer a technique of justification of new types of fastenings of slopes of hydraulic engineering constructions. The use of concrete filled geotextile mats in bank protection is brought out as a practical realization of the represented technique.

  12. Supplement Analysis for the Watershed Management Program EIS - Idaho Model Watershed Habitat Projects - L-9 Irrigation Diversion Modification



    The Bonneville Power Administration is proposing to fund a fish passage improvement project at the L-9 diversion on the Lemhi River in Lemhi County, Idaho with the Lemhi Soil and Water Conservation District. The project proposes to replace the existing rock push-up irrigation diversion dam with a single rock weir that will incorporate a geotextile membrane to create a permanent diversion. The new weir will be a v-shaped vortex weir with a six-foot wide notch for fish passage. In addition, a ramp flume will be constructed in the diversion canal between the headgate and existing fish screen to provide for water measurement. The new diversion will provide better water delivery/control and improved passage for adult and juvenile resident and anadromous fish.

  13. Interaction between Engineered Cementitious Composites Lining and Foundation Subsurface Drain

    Cleopatra Panganayi


    Full Text Available The effect of cyclic loads on the surface profiles of ECC linings cast on foundations comprising crushed stone and compacted soil was investigated. A geotextile was embedded between the crushed stone and ECC lining for some of the samples. After 28 days of water curing, the hardened surfaces were loaded and monitored for roughness and crack development by measuring surface levels and crack widths, respectively. Neither cracking nor significant variations in the lateral profiles were observed on all the samples for all the loads applied. However, significant variations which depended on the foundation types were observed in the vertical profiles. It was concluded that while ECC can resist cracking due to its high strain capacity, its flexibility causes ECC linings to assume the shape of the foundation material, which can increase the surface roughness at certain loading configurations.

  14. Dynamic and Static Combination Analysis Method of Slope Stability Analysis during Earthquake

    Liang Lu


    Full Text Available The results of laboratory model tests for simulating the slope failure due to vibration, including unreinforced slope and the slope reinforced by using geotextile, show that the slope failure occurs when a cumulative plastic displacement exceeds a certain critical value. To overcome the defects of conventional stability analysis, which evaluates the slope characteristics only by its strength parameters, a numerical procedure considering the stiffness and deformation of materials and geosynthetics is proposed to evaluate the seismic slope stability. In the proposed procedure, the failure of slope is defined when the cumulative plastic displacement calculated by a dynamic response analysis using actual seismic wave exceeds the critical value of displacement estimated by a static stability analysis considering seismic coefficient. The proposed procedure is applied to the laboratory model tests and an actual failure of slope in earthquake. The case study shows the possibility that the proposed procedure gives the realistic evaluation of seismic slope stability.

  15. Proceedings of GeoSask 2005 : The 58. Canadian Geotechnical Conference and 6. Joint CGS-IAH Groundwater Specialty Conference



    The Canadian and international geotechnical community gathered at this conference to exchange information on recent research and development concerning all sectors of geotechnical engineering, applied geology and hydrogeology. The technical sessions addressed a wide range of geotechnical engineering issues such as soil mechanics and geodynamics; geoenvironmental issues associated with contaminant transport in landfills; hydrogeology issues such as aquifer properties, hydrogeochemistry, groundwater resources, hydrogeological mapping, contaminants and remediation; geosynthetics; geotechnical modelling; rock engineering; engineering geology; mining geotechnics; buried structures; unsaturated soils and aquitards. The presentations included several geotechnical case studies that focused on broad issues such as hydraulic properties of sedimentary rock aquifers, design criteria for geotextile filters used in agricultural drainage, the long term performance of containment systems, slope stability analysis of landfills, methane emissions from landfills, shear zones in weak rocks and tailings at oil sands operations. The conference featured approximately 200 presentations, of which 17 have been catalogued separately for inclusion in this database. refs., tabs., figs.

  16. Monitoring the performance of geosynthetic materials within pavement systems using MEMS

    Attoh-Okine, Nii O.; Ayenu-Prah, Albert Y.; Mensah, Stephen A.


    Geosynthetic materials have found useful applications when unbound aggregates have been placed on cohesive soil with very weak subgrade. They have also been successfully used in retarding reflective cracking in both flexible and composite pavements. There are many applications of geosynthetics in pavement engineering yet there is considerable lack of understanding in the behavior of the material. Geosynthetic materials exhibit very peculiar properties in the area of tensile strength and reinforcement. MEMS are miniature sensing or actuating devices that can interact with other environments (provided no adverse reaction occurs) to either obtain information or alter it. With remote query capability, it appears such devices can be embedded in pavement systems as testing and monitoring tools. The aim of this paper is to propose both field and laboratory methods for monitoring geotextile performance using MEMS.

  17. Ecotoxicological response of marine organisms to inorganic and organic sediment amendments in laboratory exposures.

    Rosen, Gunther; Leather, James; Kan, Jinjun; Arias-Thode, Yolanda Meriah


    Experimental materials currently being investigated for use as amendments for the in situ remediation of contaminated sediments were assessed for their potential impacts on marine benthos. Laboratory toxicity tests involving lethal and sublethal endpoints were conducted on sediments amended with apatite, organoclay, chitin, or acetate, with the polychaete Neanthes arenaceodentata, the amphipod Eohaustorius estuarius, and the larval sheepshead minnow Cyprinodon variegatus. Amendments were mixed loosely into uncontaminated or metal-contaminated sediments, and also added inside experimental geotextile mats, at sediment dry weight (dw) concentrations ranging from 0.5% to 10%. The geotextile mats, containing apatite (5 or 10% dw), and/or organoclay (5%) did not result in adverse effects on any of the test organisms. Chitin and acetate, however, repetitively resulted in adverse effects on survival and/or adverse or positive effects on organism growth at concentrations of ≤ 2.5% dw. The adverse effects were attributed to water quality degradation in the exposure vessels (notably ammonia and dissolved oxygen concentration, for chitin and acetate, respectively) as a result of the microbial breakdown of the amendments. For N. arenaceodentata, growth was enhanced in the presence of chitin at concentrations as low as 0.5% sediment dw, which stimulated bacterial growth that may have provided an additional food source for the polychaete. Sediment chitin concentrations of 0.5% resulted in a statistically significant reduction in N. arenaceodentata body burdens of 61%, 29%, and 54%, relative to unamended contaminated sediment, for Cu, Zn, and Cd, respectively. The studies suggest a lack of inherent toxicity of these materials on the experimental organisms, as the adverse or positive responses observed are likely related to artifacts associated with laboratory exposure. Assessments in field settings are needed to verify this conclusion.

  18. Can urban tree roots improve infiltration through compacted subsoils for stormwater management?

    Bartens, Julia; Day, Susan D; Harris, J Roger; Dove, Joseph E; Wynn, Theresa M


    Global land use patterns and increasing pressures on water resources demand creative urban stormwater management. Strategies encouraging infiltration can enhance groundwater recharge and water quality. Urban subsoils are often relatively impermeable, and the construction of many stormwater detention best management practices (D-BMPs) exacerbates this condition. Root paths can act as conduits for water, but this function has not been demonstrated for stormwater BMPs where standing water and dense subsoils create a unique environment. We examined whether tree roots can penetrate compacted subsoils and increase infiltration rates in the context of a novel infiltration BMP (I-BMP). Black oak (Quercus velutina Lam.) and red maple (Acer rubrum L.) trees, and an unplanted control, were installed in cylindrical planting sleeves surrounded by clay loam soil at two compaction levels (bulk density = 1.3 or 1.6 g cm(-3)) in irrigated containers. Roots of both species penetrated the more compacted soil, increasing infiltration rates by an average of 153%. Similarly, green ash (Fraxinus pennsylvanica Marsh.) trees were grown in CUSoil (Amereq Corp., New York) separated from compacted clay loam subsoil (1.6 g cm(-3)) by a geotextile. A drain hole at mid depth in the CUSoil layer mimicked the overflow drain in a stormwater I-BMP thus allowing water to pool above the subsoil. Roots penetrated the geotextile and subsoil and increased average infiltration rate 27-fold compared to unplanted controls. Although high water tables may limit tree rooting depth, some species may be effective tools for increasing water infiltration and enhancing groundwater recharge in this and other I-BMPs (e.g., raingardens and bioswales).

  19. Bacteria in non-woven textile filters for domestic wastewater treatment.

    Spychała, Marcin; Starzyk, Justyna


    The objective of this study was preliminary identification of heterotrophic and ammonia oxidizing bacteria (AOB) cell concentration in the cross-sectional profile of geotextile filters for wastewater treatment. Filters of thicknesses 3.6 and 7.2 mm, made of non-woven textile TS20, were supplied with septic tank effluent and intermittently dosed and filtered under hydrostatic pressure. The cumulative loads of chemical oxygen demand (COD) and total solids were about 1.36 and 1.06 kg/cm2, respectively. The filters under analysis reached a relatively high removal efficiency for organic pollution 70-90% for biochemical oxygen demand (BOD5) and 60-85% for COD. The ammonia nitrogen removal efficiency level proved to be unstable (15-55%). Biomass samples for dry mass identification were taken from two regions: continuously flooded with wastewater and intermittently flooded with wastewater. The culturable heterotrophic bacteria were determined as colony-forming units (CFUs) on microbiological-selective media by means of the plate method. AOB and nitrite oxidizing bacteria (NOB) were examined using the FISH technique. A relatively wide range of heterotrophic bacteria was observed from 7.4×10(5)/cm2 to 3.8×10(6)/cm2 in geotextile layers. The highest concentration of heterotrophic bacteria (3.8×10(6)/cm2) was observed in the first layer of the textile filter. AOB were identified occasionally--about 8-15% of all bacteria colonizing the last filter layer, but occasionally much higher concentrations and ammonia nitrogen efficiency were achieved. Bacteria oxidizing nitrite to nitrate were not observed. The relation of total and organic fraction of biomass to culturable heterotrophic bacteria was also found.

  20. Definitive design report: Design report project W-025, Radioactive Mixed Waste (RMW) Land Disposal Facility NON-DRAG-OFF. Revision 1, Volume 1 and 2

    Roscha, V.


    The purpose of this report is to describe the definitive design of the Radioactive Mixed Waste (RMW) Non-Drag-Off disposal facility, Project W-025. This report presents a n of the major landfill design features and a discussion of how each of the criteria is addressed in the design. The appendices include laboratory test results, design drawings, and individual analyses that were conducted in support of the design. Revision 1 of this document incorporates design changes resulting from an increase in the required operating life of the W-025 landfill from 2 to 20 years. The rationale for these design changes is described in Golder Associates Inc. 1991a. These changes include (1) adding a 1.5-foot-thick layer of compacted admix directory-under the primary FML on the floor of the landfill to mitigate the effects of possible stress cracking in the primary flexible membrane liner (FML), and (2) increasing the operations layer thickness from two to three feet over the entire landfill area, to provide additional protection for the secondary admix layer against mechanical damage and the effects of freezing and desiccation. The design of the W-025 Landfill has also been modified in response to the results of the EPA Method 9090 chemical compatibility testing program (Golder Associates Inc. 1991b and 1991c), which was completed after the original design was prepared. This program consisted of testing geosynthetic materials and soil/bentonite admix with synthetic leachate having the composition expected during the life of the W-025 Landfill., The results of this program indicated that the polyester geotextile originally specified for the landfill might be susceptible to deterioration. On this basis, polypropylene geotextiles were substituted as a more chemically-resistant alternative. In addition, the percentage of bentonite in the admix was increased to provide sufficiently low permeability to the expected leachate.

  1. Preliminary Analysis of Engineering Effect of Crushed Rocks Mat Embankment in Heimahe Section of Qinghai-Tibet Highway%青藏公路黑马河试验段碎石垫层路基工程效果初步分析

    李东庆; 常法; 张坤; 房建宏; 徐安花


    基于青藏公路黑马河试验段碎石垫层路基近1 a的温度、水分监测资料,初步分析了碎石垫层路基温度,水分的发展与分布特征以及造成这些差异的原因,并与传统的砂砾垫层比较.结果表明:碎石垫层加隔水土工布能够更好的削弱毛细水自下而上的迁移,起到了一定的隔水排水效果,对于防治季节性冻土路基冻胀病害具有积极作用.%Based on the monitoring data of moisture and temperature along the National Road 109 in Qinghai Province,the changes and induced causes of temperatures and moistures at different positions of an embankment under the action of external climate conditions were systematically analyzed.The change rates and induced causes of moistures for the traditional gravel embankment and the crushed rock mat embankment with waterproof geotextile were discussed.Further more,the effects of these differences on the frost heaving of embankment were also analyzed.It is found that the rushed rock mat embankment with waterproof geotextile is better than the traditional gravel embankment for preventing frost heaving and boiling of embankment in seasonally frozen soil regions,even that there are top-down migration of ground surface water,and soil moisture migration under winter negative temperature gradient and capillary action from the bottom to promote the migration of the soil water.

  2. Reducing Open Cell Landfill Methane Emissions with a Bioactive Alternative Daily

    Helene Hilger; James Oliver; Jean Bogner; David Jones


    made but prone to rapid desiccation. Bacterial adsorption onto foam padding, natural sponge, and geotextile was successful. The most important factor for success appeared to be water holding capacity. Prototype biotarps made with geotextiles plus adsorbed methane oxidizing bacteria were tested for their responses to temperature, intermittent starvation, and washing (to simulate rainfall). The prototypes were mesophilic, and methane oxidation activity remained strong after one cycle of starvation but then declined with repeated cycles. Many of the cells detached with vigorous washing, but at least 30% appeared resistant to sloughing. While laboratory landfill simulations showed that four-layer composite biotarps made with two different types of geotextile could remove up to 50% of influent methane introduced at a flux rate of 22 g m{sup -2} d{sup -1}, field experiments did not yield high activity levels. Tests revealed that there were high hour-to-hour flux variations in the field, which, together with frequent rainfall events, confounded the field testing. Overall, the findings suggest that a methanotroph embedded biotarp appears to be a feasible strategy to mitigate methane emission from landfill cells, although the performance of field-tested biotarps was not robust here. Tarps will likely be best suited for spring and summer use, although the methane oxidizer population may be able to shift and adapt to lower temperatures. The starvation cycling of the tarp may require the capacity for intermittent reinoculation of the cells, although it is also possible that a subpopulation will adapt to the cycling and become dominant. Rainfall is not expected to be a major factor, because a baseline biofilm will be present to repopulate the tarp. If strong performance can be achieved and documented, the biotarp concept could be extended to include interception of other compounds beyond methane, such as volatile aromatic hydrocarbons and chlorinated solvents.

  3. Geocomposite with Superabsorbent as an Element Improving Water Availability for Plants on Slopes

    Pawlowski, A.; Lejcus, K.; Garlikowski, D.; Orzeszyna, H.


    saturation, could infiltrate deeper, where water retained by superabsorbent would be much more difficult to reach by plants root system. To avoid disadvantages, listed above, of using superabsorbents in slope cover layer of soil, a special gecomposite has been developed. In basic form it consists of dry superabsorbent paticles placed between 2 layers of geotextiles. The non woven geotextile is extensible enough to let the superabsorbent swell, when it absorbs high amounts of water. Geotextile separates superabsorbent from surrounding soil and does not allow changing its properties by gel penetrating pore space. It is not a barrier for roots to access the water retained in the geocomposite. Roots, as tests have proven, form dense system connected with geocomposite. Positive influence on roots system's shear resistance, when geocomposite has been placed in soil layer, had been observed. There are many different possibilities of geocomposite arrangement on slopes to be protected by plants cover. It can be placed horizontally in parallel lines, it can form a grid like pattern or can be used at defined point to support water supply of bushes. Possibilities of gecomposite usage are not limited to bioengineering. It can be used in many sectors of agriculture, where precisely placed "water reservoir" is better, then uncontrolled mixing of superabsorbent with the soil. If necessary it can be removed, which is not possible, if superabsorbent particles are applied directly to the soil. So using the geocomposite one can fully profit from its advantages avoiding at the same time its negative influence on soil properties.

  4. Analyzing the importance of wind-blown snow accumulations on Mount

    Nestler, Alexander; Huss, Matthias; Ambartsumian, Rouben; Hambarian, Artak; Mohr, Sandra; Santi, Flavio


    Armenia's climate has a predominantly continental character with high amounts of precipitation and low temperatures during wintertime and a lack of precipitation together with high temperatures during summer. On the volcano Mount Aragatz, snow is relocated by strong winds into massive accumulations between 2500 and 4100 m a.s.l. during the winter season. These snow accumulations appear every winter in regular patterns as cornices on the lee side of sharp edges, such as those of ridges and canyons, which are arranged in a radial manner around the central crater. The biggest cornices almost outlast the hot period and provide considerable amounts of melt water until they disappear completely by the end of August. Snow melt water is known to have a high economic importance for agriculture on the slopes of Mount Aragatz and in the surroundings of Armenia's captial Yerewan. The aim of this study is to estimate the quantity of water naturally stored as snow on Mount Aragatz, and to what degree the use of geotextiles can prolong the lives of these snow accumulations. The characteristics and the spatial distribution of snow cornices on Mount Aragatz were determined using classical glaciological methods in June/July 2011 and 2012, involving snow depth soundings, water equivalent measurements and snow melt monitoring using ablation stakes, together with GPS mappings and classifications obtained from satellite images of the snow cornices. The combination of these data with ASTER DEMs and local weather data allows the modelling of the formation of wind-driven snow accumulations. Statistical relationships between the measured extent and volume of the snow cornices and surface parameters such as slope, aspect and curvature are established. In order to analyze the meltdown of the snow accumulations and the consequent impacts on runoff generation and the hydrological regime, a glacio-hydrological model integrating topographic parameters and meteorological data is applied. The

  5. 垃圾填埋场衬垫系统穿刺性能评价%Evaluation of puncture performance of liner system for solid waste landfills

    许四法; 张勇; 王哲


    垃圾中含有铁、玻璃和陶瓷等尖锐物,在荷载作用下极有可能使衬垫系统发生破坏,导致渗滤液流入地下污染周边环境,如何正确评价衬垫系统的穿刺性能很重要.考虑材料的抗拉强度、厚度以及穿刺棒的直径提出了衬垫系统穿刺力的评价公式,并与试验结果进行了比较.结果表明,单层土工膜的抗穿刺力试验结果与评价值比较吻合,但由土工膜与无纺布组成的衬垫系统抗穿刺力的试验值与评价结果有一定偏差;土工膜与无纺布一起使用能大幅度提高衬垫系统的抗穿刺能力,因此土工膜上应铺设无纺布有利于保护衬垫系统;土工膜的抗拉强度越大,抗穿刺能力越强;基础的存在能在一定程度上提高衬垫系统的抗穿刺性能.所得结果对垃圾填埋场衬垫系统的设计具有一定的指导意义.%Because of the containing iron, glass and ceramics in solid waste, the geomembrane may be easily damaged and results in infiltrating into the surrounding ground and water; so it is very important how to evaluate the puncture performance of liner system.Taking into account the tensile strength.the thickness of geomembrane and the diameter of puncture probe, an evaluation formula of puncture resistance is presented based on the thin-walled structural mechanics theory; and the calculated values are compared with the experimental values.The results show that the calculation results of geomembrane are consistent with the puncture test results; but the calculation results of liner system composed of geomembrane and geotextiles are only about 70 percent of the test results.Geotextile used together with geomembrane could significantly improve puncture performance of liner system; so the geotextile should be spread on geomembrane for protection geomembrane.With an increase of tensile strength of geomembrane.puncture resistance becomes larger.Puncture resistance of geomembrans placed on compacted soil

  6. Avaliação de recomendações normativas sobre o uso de ensaios no controle de qualidade de fabricação de geossintéticos Evaluation of standard recommendations on the use of tests for manufacturing quality control of geosynthetics

    Carina M. L. Costa


    Full Text Available A utilização de materiais poliméricos designados por geossintéticos tem aumentando significativamente nos últimos anos na Engenharia Civil. Para desempenhar adequadamente a função para a qual foram projetados, os geossintéticos devem ser submetidos a um rigoroso processo de controle de qualidade durante a fabricação. Discussões sobre a freqüência e os principais tipos de ensaios de laboratório utilizados nesse processo de controle para dois tipos de geossintéticos, os geotêxteis e as geomembranas, os materiais mais utilizados da famíla dos geossintéticos, são abordados no presente trabalho. As análises efetuadas com base em normas disponíveis no Brasil, nos EUA e na Europa mostram que no cenário nacional não há recomendações normativas sobre o controle de qualidade para a maioria das aplicações de geotêxteis e geomembranas, sendo o assunto pouco discutido na literatura técnica. No cenário internacional, as normas Européias se destacam como o conjunto de práticas mais completo para ensaios de controle de qualidade de fabricação, considerando os diversos tipos de aplicação dos geossintéticos na Engenharia Civil.The use of polymeric materials known as geosynthetics in Civil Engineering applications has increased significantly in the last few years. In order to perform adequately, geosynthetics need to be manufactured according to rigorous quality control procedures. This paper addresses the frequency and the main types of laboratory tests used for quality control of geotextiles and geomembranes, which are the most largely used materials within the geosynthetic family. Analyses based on technical standards from Brazil, USA and Europe show the need of quality control recommendations for a large number of applications of geotextiles and geomembranes in Brazil. Also, very limited information on this topic is available in Brazilian literature. Conversely, European standards on the subject take into consideration a

  7. 由淀粉获得经济有效的纺织品%Cost effective textiles from starch

    亚琛工业大学 纺织技术研究所 德国


    Cost effective,broad availability and biodegradability of materials produced from renewable resources are the key factors demanded by the textile market. Starch-based products fulfill the listed requirements and therefore show great potential to be used for the applications such as apparel,geotextiles and hygiene textiles. However,the native starches do not show sufficient thermoplastic behavior to be processed through melt spinning into fibers. The chemical modification and blending of starch with other biopolymers is a novel approach to modify the starch properties in order to facilitate melt processing of obtained products using e.g. continuous reaction process equipment. The project “Star-Tex”is aimed at the application of starch modification and will develop textile products,which can be used in apparel,geotextile and the hygiene sector of the textile industry.%通过再生资源制得的材料的经济有效性、应用广泛性及生物可降解性是纺织市场考虑的关键因素。淀粉基产品满足上述这些要求,因此在服装、土工材料及卫生用纺织品等方面具有极大的应用潜力。然而,天然淀粉的热塑性不佳,不能通过熔融纺丝的方法加工成纤维。通过化学改性和将淀粉与其他生物高聚物共混是改变淀粉性能的一种创新方法,可促进淀粉的熔融加工,如使用连续加工设备实现熔融纺丝获得纤维产品。Star-Tex 项目针对改性淀粉的应用,以开发应用于服装、土工材料及医疗卫生等领域的纺织产品。

  8. Kajian Rumput Vetiver Sebagai Pengaman Lereng Secara Berkelanjutan

    Susilawati Susilawati


    Full Text Available Flores is the island in the NTT province, which has a row of volcanoes, with the mountainous topography. Transportation is state road, along the coast with high cliffs on the other side. That often causes problems during the rainy season as several landslides. Various methods are used to overcome this landslide. Studies on vetiver grass as slope protection done to secure the slopes on a sustainable basis. First, an evaluation done for the slope construction along the slope safety from Nangaroro to Aegela, which are using vetiver grass as a safety slopes in addition to other security structures. It is also done for the same job of the road from Ende to Nangaroro and Ende-Detusoko. This study covers the technical aspects, ecological, construction and sustainability of the infrastructure that has been built. Furthermore, it is done the literature study to find more appropriate method, environmentally friendly and sustainable in securing these slopes problematic. From the literature studies and the field survey done, it can be concluded and recommended several models of eco-friendly structural design of vetiver grass and geotextile for slope protection, which is based on technical-meet standard strength, ecologically-friendly environment, locally-developed local wisdom, so it is easy to construct.

  9. Statistical tools applied in the characterisation and evaluation of a thermo-hygrometric corrective action carried out at the Noheda archaeological site (Noheda, Spain).

    Valero, Miguel Ángel; Merello, Paloma; Navajas, Ángel Fernández; García-Diego, Fernando-Juan


    The Noheda archaeological site is unique and exceptional for its size, and the quality and conservation condition of the Roman mosaic pavement covering its urban pars. In 2008 a tent was installed as protection from rain and sun. Being of interest to characterise the microclimate of the remains, six probes with relative humidity and temperature sensors were installed in 2013 for this purpose. Microclimate monitoring allowed us to check relative humidity differences resulting from the groundwater level, as well as inner sensors reaching maximum temperatures higher than the outdoors ones as a consequence of the non-ventilated tent covering the archaeological site. Microclimatic conditions in the archaeological site were deemed detrimental for the conservation of the mosaics. Thus, in summer 2013, expanded clay and geotextile were installed over the mosaics as a corrective action. The outcomes of this study have proven the effectiveness of this solution to control temperature and relative humidity, helping to configure a more stable microclimate suitable for preservation of the mosaic.

  10. Permeable pavement and stormwater management systems: a review.

    Imran, H M; Akib, Shatirah; Karim, Mohamed Rehan


    Uncontrolled stormwater runoff not only creates drainage problems and flash floods but also presents a considerable threat to water quality and the environment. These problems can, to a large extent, be reduced by a type of stormwater management approach employing permeable pavement systems (PPS) in urban, industrial and commercial areas, where frequent problems are caused by intense undrained stormwater. PPS could be an efficient solution for sustainable drainage systems, and control water security as well as renewable energy in certain cases. Considerable research has been conducted on the function of PPS and their improvement to ensure sustainable drainage systems and water quality. This paper presents a review of the use of permeable pavement for different purposes. The paper focuses on drainage systems and stormwater runoff quality from roads, driveways, rooftops and parking lots. PPS are very effective for stormwater management and water reuse. Moreover, geotextiles provide additional facilities to reduce the pollutants from infiltrate runoff into the ground, creating a suitable environment for the biodegradation process. Furthermore, recently, ground source heat pumps and PPS have been found to be an excellent combination for sustainable renewable energy. In addition, this study has identified several gaps in the present state of knowledge on PPS and indicates some research needs for future consideration.


    Jakub Nieć


    Full Text Available Small water bodies, for example garden ponds, play many functions in the environment, including biocenotic, hydrological, climatic, sozological, landfill-creative, and aesthetic. Due to their small size, these reservoirs are sensitive to external and internal factors, they are also a common natural contaminants receivers. Nonwoven filters have been investigated for several years as a useful device for treatment of domestic wastewater pre-treated in a septic tank. The aim of this study was to verify the possibility of using this type of filters for water originating from small water body purification. The effectiveness of filters were tested on the water originating from the garden pond, contained high levels of nutrients and intensive algal bloom. Research was carried out on three filters (each filter consisted of four geotextile TS 20 layers. Basic water quality indicators: total suspended solids, turbidity, COD and BOD5, temperature, pH and dissolved oxygen were measured. The research results can be considered as satisfactory in terms of mechanical treatment (removal of turbidity and total suspended solids. An important positive effect of the filters was the oxygenation of the treated water, which is especially important for fish.

  12. Soil intervention as a strategy for lead exposure prevention: the New Orleans lead-safe childcare playground project.

    Mielke, Howard W; Covington, Tina P; Mielke, Paul W; Wolman, Fredericka J; Powell, Eric T; Gonzales, Chris R


    The feasibility of reducing children's exposure to lead (Pb) polluted soil in New Orleans is tested. Childcare centers (median = 48 children) are often located in former residences. The extent of soil Pb was determined by selecting centers in both the core and outlying areas. The initial 558 mg/kg median soil Pb (range 14-3692 mg/kg) decreased to median 4.1 mg/kg (range 2.2-26.1 mg/kg) after intervention with geotextile covered by 15 cm of river alluvium. Pb loading decreased from a median of 4887 μg/m(2) (454 μg/ft(2)) range 603-56650 μg/m(2) (56-5263 μg/ft(2)) to a median of 398 μg/m(2) (37 μg/ft(2)) range 86-980 μg/m(2) (8-91 μg/ft(2)). Multi-Response Permutation Procedures indicate similar (P-values = 0.160-0.231) soil Pb at childcare centers compared to soil Pb of nearby residential communities. At ∼$100 per child, soil Pb and surface loading were reduced within hours, advancing an upstream intervention conceptualization about Pb exposure prevention.

  13. Influence of hydraulic hysteresis on the mechanical behavior of unsaturated soils and interfaces

    Khoury, Charbel N.

    Unsaturated soils are commonly widespread around the world, especially at shallow depths from the surface. The mechanical behavior of this near surface soil is influenced by the seasonal variations such as rainfall or drought, which in turn may have a detrimental effect on many structures (e.g. retaining walls, shallow foundations, mechanically stabilized earth walls, soil slopes, and pavements) in contact with it. Thus, in order to better understand this behavior, it is crucial to study the complex relationship between soil moisture content and matric suction (a stress state variable defined as pore air pressure minus pore water pressure) known as the Soil Water Characteristic Curve (SWCC). In addition, the influence of hydraulic hysteresis on the behavior of unsaturated soils, soil-structure interaction (i.e. rough and smooth steel interfaces, soil-geotextile interfaces) and pavement subgrade (depicted herein mainly by resilient modulus, Mr) was also studied. To this end, suction-controlled direct shear tests were performed on soils, rough and smooth steel interfaces and geotextile interface under drying (D) and wetting after drying (DW). The shearing behavior is examined in terms of the two stress state variables, matric suction and net normal stress. Results along the D and DW paths indicated that peak shear strength increased with suction and net normal stress; while in general, the post peak shear strength was not influenced by suction for rough interfaces and no consistent trend was observed for soils and soil-geotextiles interfaces. Contrary to saturated soils, results during shearing at higher suction values (i.e. 25 kPa and above) showed a decrease in water content eventhough the sample exhibited dilation. A behavior postulated to be related to disruption of menisci and/or non-uniformity of pore size which results in an increase in localized pore water pressures. Interestingly, wetting after drying (DW) test results showed higher peak and post peak shear

  14. Modelling the failure modes in geobag revetments.

    Akter, A; Crapper, M; Pender, G; Wright, G; Wong, W S


    In recent years, sand filled geotextile bags (geobags) have been used as a means of long-term riverbank revetment stabilization. However, despite their deployment in a significant number of locations, the failure modes of such structures are not well understood. Three interactions influence the geobag performance, i.e. geobag-geobag, geobag-water flow and geobag-water flow-river bank. The aim of the research reported here is to develop a detailed understanding of the failure mechanisms in a geobag revetment using a discrete element model (DEM) validated by laboratory data. The laboratory measured velocity data were used for preparing a mapped velocity field for a coupled DEM simulation of geobag revetment failure. The validated DEM model could identify well the critical bag location in varying water depths. Toe scour, one of the major instability factors in revetments, and its influence on the bottom-most layer of the bags were also reasonably represented in this DEM model. It is envisaged that the use of a DEM model will provide more details on geobag revetment performance in riverbanks.


    M.K. Alam


    Full Text Available Haor is the local name of the saucer-shaped, naturally depressed areas of Bangladesh. There are 414 haors in the northeast region that comprise approximately 17% of the country. These areas are submerged under deep water from July to November due to the overflow of rivers and heavy rainfall, causing them to appear like seas with erosive waves. Recently, the wave attack has drastically increased because of de-plantation and changing cropping patterns to allow for more agricultural production. The local people, government and Non-Government Organisations (NGOs have tried many techniques to protect life and property against wave attacks. A cost comparison shows that Cement Concrete (CC blocks over geotextile on the slope embankment is a cost-effective, environment friendly and socially acceptable method to prevent loss of life and property. However, the design rules employed by the engineers are faulty because there is knowledge gap in the application of wave hydraulics among these professionals. As a result, damage frequently occurs and maintenance costs are increasing. This study explores the sustainability of the CC blocks used in the Haor areas by evaluating two case studies with the verification of available design rules.

  16. Multicriteria decision analysis to assess options for managing contaminated sediments: Application to Southern Busan Harbor, South Korea.

    Kim, Jongbum; Kim, Suk Hyun; Hong, Gi Hoon; Suedel, Burton C; Clarke, Joan


    Many years of untreated effluent discharge from residential areas, a shipyard, a marina, and a large fish market resulted in substantial contamination of bottom sediment in Southern Busan Harbor, South Korea. Contaminants in these sediments include heavy metals and organic compounds. Newly introduced regulations for ocean disposal of dredged material in South Korea pose significant challenges, because the previous practice of offshore disposal of contaminated dredged material was no longer possible after August 2008. The South Korean government has mandated that such sediments be assessed in a way that identifies the most appropriate dredged material management alternative, addressing environmental, social, and cost objectives. An approach using multicriteria decision analysis (MCDA) in combination with comparative risk assessment was used as a systematic and transparent framework for prioritizing several dredged sediment management alternatives. We illustrate how MCDA can recognize the multiple goals of contaminated sediment management. Values used in weighting decision criteria were derived from surveys of stakeholders who were sediment management professionals, business owners, or government decision makers. The results of the analysis showed that land reclamation was the preferred alternative among cement-lock, sediment washing, 3 contained aquatic disposal alternatives (one in combination with a hopper dredge), geotextile tubes, solidification, and land reclamation after solidification treatment. Land reclamation was the preferred alternative, which performed well across all MCDA objectives, because of the availability of a near-shore confined disposal facility within a reasonable distance from the dredging area.

  17. Finite Element Modelling for Tensile Behaviour of Thermally Bonded Nonwoven Fabric

    Gao Xiaoping


    Full Text Available A nonwoven fabric has been widely used in geotextile engineering in recent years; its tensile strength is an important behaviour. Since the fibre distributions in nonwoven fabrics are random and discontinuous, the unit-cell model of a nonwoven fabric cannot be developed to simulate its tensile behaviour. This article presents our research on using finite element method (FEM to study the tensile behaviour of a nonwoven fabric in macro-scale based on the classical laminate composite theory. The laminate orientation was considered with orientation distribution function of fibres, which has been obtained by analysing the data acquired from scanning electron microscopy with Hough Transform. The FE model of a nonwoven fabric was developed using ABAQUS software; the required engineering constants of a nonwoven fabric were obtained from experimental data. Finally, the nonwoven specimens were stretched along with machine direction and cross direction. The experimental stress-strain curves were compared with the results of FE simulations. The approximate agreement proves the validity of an FE model, which could be used to precisely simulate the stress relaxation, strain creep, bending and shear property of a nonwoven fabric.

  18. Statistical Tools Applied in the Characterisation and Evaluation of a Thermo-Hygrometric Corrective Action Carried out at the Noheda Archaeological Site (Noheda, Spain

    Miguel Ángel Valero


    Full Text Available The Noheda archaeological site is unique and exceptional for its size, and the quality and conservation condition of the Roman mosaic pavement covering its urban pars. In 2008 a tent was installed as protection from rain and sun. Being of interest to characterise the microclimate of the remains, six probes with relative humidity and temperature sensors were installed in 2013 for this purpose. Microclimate monitoring allowed us to check relative humidity differences resulting from the groundwater level, as well as inner sensors reaching maximum temperatures higher than the outdoors ones as a consequence of the non-ventilated tent covering the archaeological site. Microclimatic conditions in the archaeological site were deemed detrimental for the conservation of the mosaics. Thus, in summer 2013, expanded clay and geotextile were installed over the mosaics as a corrective action. The outcomes of this study have proven the effectiveness of this solution to control temperature and relative humidity, helping to configure a more stable microclimate suitable for preservation of the mosaic.

  19. Filtros para Água para da Chuva: Análise de Eficiência



    Full Text Available The improper use of water in the world today is a constant concern, too much drinking water is wasted for certain purposes could be used water not potable, but yes, good clean water and rainwater. An alternative to using rainwater with higher quality is to filter it in sand filters. The objectives of this study were: (a estimate the maximum flow of three different kind of filters, (b determine in laboratory the effectiveness of the three different compositions; (c compare the efficiency of the three filter systems to retain solid waste present in rainwater, allowing the improvement of its quality . The experimental work was conducted at the Laboratory of Environmental Engineering Center Franciscan University using as a sand filter a water tank of 250 liters with filter materials such as gravel, sand, geotextile and polyurethane sponge. Results obtained by the filters designed for filtration of rainwater flows were 11,800 L. h-1 (filter 1, 630 L. h-1 (filter 2 and 9300 L. h-1 (filter 3. Filter 2 showed a improved efficiency comparison between the filters, but also lower flow rate.

  20. Experimental research on accelerated consolidation using filter jackets in fine oil sands tailings

    Tol van, F.; Yao, Y.; Paaseen van, L.; Everts, B. [Delft Univ. of Technology, Delft (Netherlands). Dept. of Geotechnology


    This PowerPoint presentation discussed prefabricated vertical drains used to enhance the dewatering of fine oil sand tailings. Filtration tests conducted with thickened tailings on standard PVD jackets were presented. Potential clogging mechanisms included clogging of the filter jacket by particles, blinding of the jackets by filter cake, the decreased permeability of consolidated tailings around the drain, and the clogging of the filter jacket with bitumen. Polypropylene and polyester geotextiles were tested in a set-up that replicated conditions observed at 5 to 10 meters below mud level in an oil sand tailings pond. A finite strain consolidation model was used to interpret results obtained in the experimental study. The relationship between the void ratio and hydraulic conductivity was investigated. Results of the study showed that neither the bitumen nor the fines in the sludge cause serious blinding of the filter jackets during the 40 day test period. The consolidation process was adequately simulated with the finite strain consolidation model. tabs., figs.

  1. Drawing green in New York city : aesthetic design and sustainable development

    Wayland-Smith, S. [Balmori Associates Inc., New York, NY (United States)


    Strong aesthetic design can advance the development of the green roof industry in the United States. Many architects are beginning to adopt green roofs as a design element that merges architecture and landscapes in sustainable systems. Innovative design of green roofs will draw attention to the technology and create momentum for the green roof movement, which may lead to more incentives and policy programs. With the development of a range of watertight membranes, geotextiles and specific soil substrates, the idea of merging landscape and architecture within a single structure is now a more viable and efficient reality. Design intent needs to be clearly illustrated. This paper provided an outline of the philosophy and practices of Balmori, a green roof design firm that envisions the rooftops of New York City as a potential second central park. Green roofs designed by the organization to date include the Solaire building roof garden; a green roof network in Long Island; the Gratz Industries and Silvercup Studios roof projects; and a new residential green roof for a building in Manhattan. Details of funding, partnerships and technical specifications were provided for each project. Descriptions of the completed and ongoing projects were used to illustrate Balmori's philosophy of promoting sustainable green roofs that alter their urban context through aesthetic means. It was concluded that it is only when green roof technologies are conceived as being powerful design tools as opposed to ecological experiments will their widespread adoption occur.1 ref., 4 figs.

  2. Membrane behavior of clay liner materials

    Kang, Jong Beom

    Membrane behavior represents the ability of porous media to restrict the migration of solutes, leading to the existence of chemico-osmosis, or the flow of liquid in response to a chemical concentration gradient. Membrane behavior is an important consideration with respect to clay soils with small pores and interactive electric diffuse double layers associated with individual particles, such as bentonite. The results of recent studies indicate the existence of membrane behavior in bentonite-based hydraulic barriers used in waste containment applications. Thus, measurement of the existence and magnitude of membrane behavior in such clay soils is becoming increasingly important. Accordingly, this research focused on evaluating the existence and magnitude of membrane behavior for three clay-based materials that typically are considered for use as liners for waste containment applications, such as landfills. The three clay-based liner materials included a commercially available geosynthetic clay liner (GCL) consisting of sodium bentonite sandwiched between two geotextiles, a compacted natural clay known locally as Nelson Farm Clay, and compacted NFC amended with 5% (dry wt.) of a sodium bentonite. The study also included the development and evaluation of a new flexible-wall cell for clay membrane testing that was used subsequently to measure the membrane behaviors of the three clay liner materials. The consolidation behavior of the GCL under isotropic states of stress also was evaluated as a preliminary step in the determination of the membrane behavior of the GCL under different effective consolidation stresses.

  3. An Analytical Model for Predicting Stab Resistance of Flexible Woven Composites

    Hou, Limin; Sun, Baozhong; Gu, Bohong


    Flexible woven composites have been widely used in geotextiles and light weight building structures. The stab resistance behavior of the flexible woven composite is an important factor for the application design. This paper reports an analytical model for predicting stab resistance of flexible woven composites under perpendicular stab with a blunt steel penetrator. The analytical model was established based on the microstructure and the deformation shape of the flexible woven composite under normal penetration. During the quasi-static stab penetration, the strain energies of warp and weft yarns and resins have been calculated. The stab resistance was calculated from the strain energies of the flexible woven composite. Furthermore, the contributions of the warp and weft yarns, resins to the stab resistance have been analyzed. It was found the three constituents have near the same contribution to the stab resistance. The higher value of weaving density, strength of yarns and especially the higher strength coating resins will lead the higher stab resistance. With the analytical model, the stab resistance would be expected to be designed in an efficient way with an acceptable precision.

  4. Minimum energy design using grassed spillways

    Lewis, B. [FIE Aust, Melbourne (Australia)


    Small dams for rural communities in Australia often fail due to the Spillway or bywash, because it receives insufficient attention during the design, construction and maintenance processes. More thorough investigation and improved standards of design and construction are needed in order to resolve problems. This paper described some of the reasons for adopting grass spillways on farm dams. It compared grass and earth spillways and also discussed spillway design factors such as site conditions, peak flow estimation, and design spillway size. The factors affecting selection of spillway type and design include safety requirements, hydrological conditions, geological and site topographical conditions, and type of dam. Factors involved in grass selection in spillway design were also identified. These include climate, soils, land systems, and quality and duration of discharge, growth characteristics, hydraulic behaviour, and maintenance. It was concluded that additional research is needed regarding methods of establishing grass cover to inlets and outlet spillway. In particular, there is a need to evaluate the growth of grasses through plastic meshes and geotextiles, which could provide protection against erosion while the grass is becoming established. 10 refs., 4 tabs.

  5. Levee Scour Protection for Storm Waves

    Johnson, E.; Sustainable; Resiliency in Levee Scour Protection


    Earnest Johnson, Firat Y. Testik *, Nadarajah Ravichandran Civil Engineering, Clemson University, Clemson, SC, USA * Contact author Levee failure due to scouring has been a prominent occurrence among intense storm surges and waves, giving rise to the implementation of various scour protection measures over the years. This study is to investigate the levee scour and to compare different scour protection measures on a model-levee system in a laboratory wave tank. The protection measures that are tested and compared for their effectiveness in this study include turf reinforcement mats, woven geotextiles, and core-locs. This is an ongoing research effort and experiments are currently being conducted with model levees constructed based upon the United States Army Corps of Engineers' levee design and construction guidelines under various simulated storm conditions. Parameters such as wave elevations, deformation time history of the floodwall, and the scour depth are measured in each test. The finding of this research will be translated to provide effective scour protection measures for robust levee designs.

  6. Centrifuge modelling and finite element analysis of reinforced fly ash walls

    Mandal, J.N.; Shaikh, Z. [Indian Institute of Technology, Bombay (India). Dept.of Civil Engineering


    Centrifuge modeling of unreinforced and reinforced fly ash wall was done with varying water content to study the failure pattern and their behaviour. Fly ash was from the ash disposal pond of Koradi Thermal Power Plant (KTPP) in Nagpur, India. The fly ash walls without reinforcement are liable to fail and sudden failure of slopes have been noticed. Unreinforced fly ash wall shows a sharp decrease in the strength for a water content on the higher side of optimum moisture content. Fly ash walls reinforced with geotextiles performed satisfactorily even at very high rpm. A non-linear finite element analysis was carried out to evaluate the distribution of stresses and deformations. The lateral deformation obtained by the finite element analysis and the centrifuge modeling is found to be sufficiently less than the permissible limit. The lateral deformations of the reinforced retaining wall does not decrease appreciably with increase in the stiffness of reinforcement but decreases as the modulus of the backfill soil increases. More research is required on the long-term mechanical and chemical behaviour of the fly ash material and the long-term stability of the reinforced fly ash walls. 14 refs., 3 tabs.

  7. New pollution reduction technologies through tank sealing of slag and ashes pits

    Bruell, A.; Revenco, V. [Institutul de Stuidii Si Proiectari Energetice S.A. (ISPE), Bucharest (Hungary)


    Under the Romanian environment protection law provision no. 137/1995, the existing slag and ashes pits raise problems due to the exfiltrations from the pits tank towards the phreatic water sheet. The design includes the following steps to be taken: pit bed waterproofing under new works; bed ends sealing, parallel with pit aggradation for dumps in operation; waterproofing of aggradation dikes. The conventional solution is clay plating. When works are performed under bad weather conditions, and clay must be brought from remote distances, the clay plating solution should be compared to the geocomponents one. The latter area combination of geotextiles and bentone material that can be placed easily, joint in situ, and can be paid at negative temperatures. Once wet, geo components become impermeable. The paper describes the sealing performed at the slag and ashes pit of Vales Ceplea at Turceni thermal power plant, and the sealing solution being developed at the Beterega Nord slag and ashes pit at Rovinari thermal power plant. The necessary geophysical characteristics of the material are pointed out.

  8. Sustainable Forward Operating Bases


    private and public sector research, anecdotal first person accounts, and public  articles , and attended conferences, symposiums, and workshops on energy...lined with  geotextile  fabrics and  filled with dirt to form barriers. Most HESCOs used in Iraq are either Mil 1 (4.5’x3.5’x32’) or Mil 2  (2’x2’ over $50.00 per gallon to deliver water to the  tactical edge.121  Huge supply requirement.   Technically , bottled water follows the Class I

  9. 西安市道路雨水口截污挂篮试验研究%On the use of interception baskets to prevent road gully runoff pollution in Xi'an

    陈莹; 赵剑强; 张小玲; 胡博; 毛鹤群


    methods. The effective practices of the Americans in this way can serve a succefful example in this connection. In recent years, although studies on road runoff pollution in our country has gained significant development and some re-searchers have laid down basic work in this way, rare results and available technological devices have been gained on the practical pollution control for the prevention. To overcome this inefficiency and meet the practical controlling demand, we have designed an interception basket device to be applied to road gully in Xi' an city in this paper and made systematic studies on the runoff quality, precipitation characteristics on the road gullies in accordance with Xi'an actual situation. In this paper, we have also discussed the permeability, work status, pollution interception efficiency and replacement cycle of interception basket in the local situation. Results show that the area of overflow loophole of the interception baskets should be at least 0.0098 m2 so as to avoid the road flooding when the storm hitting of every five-year recycling interval turns to repeat. The relation of filtration flux with filtering head of geotextile proves to be linear in nature. That is to say, the more the geotextile mass per unit is, the less the permeability will be. The effective filtering heights of interception basket made by geotextile of 300 g/m2, 150 g/m2 and 130 g/m2 are likely to be at least 175 mm, 94 mm and 75 mm, respectively, on the condition that the overflow will not happen when storm of 5 years recurrence interval occurs. In addition, the SS removing rites of interception baskets made by the geotextile of 300g/m2 , 150 g/m2 arid 130 g/m2 would likely be equal to 76.5% , 69.4% and 56.0% , respectively .

  10. 基于多孔渗入式的 PE 管型公路渗沟应用研究%Application of the Porous Infiltration PE Pipe in Highway Underground Trench

    吴颖峰; 夏国权; 潘翔


    多孔渗入式PE管型渗沟适用于路基地下排水较长的路段, PE管道结构抗变形能力强,表面开孔率高,错位开孔设置合理,外裹透水土工布反滤效果好,排水性能良好,施工快速方便。多孔渗入式PE管型渗沟的有效应用,既延长了路基使用年限,又提高了公路服务能力,具有很好的应用前景。%The porous infiltration PE pipe is suitable for the underground drainage long sections in highway under-ground Trench. There are strong resistance to deformation ,surface high hole rate and reasonable dislocation hole of the PE pipe structure. In addition ,there are good filter performance of outside permeable geotextile ,excellent drainage per-formance of PE pipe and convenient construction. The effective application of porous infiltration PE pipe in highway trench not only prolongs the service life of subgrade ,but also improves the highway service ability. Therefore ,the porous infiltration PE pipe has good application prospect in highway underground trench .

  11. Construction Control Method for Waterproof and Drainage of Highway Tunnel%公路隧道防排水施工控制方法



    隧道施工期间防排水施工不达标,对于隧道后期运营以及隧道使用寿命存在很大的影响,且进行防排水处理难度大、费用高,效果差.以米仓山隧道为例,介绍了公路隧道防排水施工方法,铺设PVC复合土工布防水板工艺、排水管道施工等,希望对相关领域工程设计与施工实践等起到一定的借鉴作用.%The non-compliance waterproof and drainage system during tunnel construction would be a huge threat to operation and the service life of the tunnel.Besides,it will increase the difficulties and costs for repairing,and normally will receive poor effect.Taking Micangshan Tunnel as an example,this paper introduces the highway tunnel waterproof and drainage construction,PVC composite geotextile waterproof board technology,drainage pipeline construction,etc.Hopefully,it may provide some reference to related engineering design and construction practice.

  12. Investigation of Structure and Property of Indian Cocos nucifera L. Fibre

    Basu, Gautam; Mishra, Leena; Samanta, Ashis Kumar


    Structure and physico-mechanical properties of Cocos nucifera L. fibre from a specific agro-climatic region of India, was thoroughly studied. Fine structure of the fibre was examined by Fourier Transform Infra-Red (FTIR) spectroscopy, Thermo-Gravimetric Analysis (TGA), X-Ray Diffraction (XRD), component analysis, Scanning Electron Microscope (SEM) and optical microscope. SEM shows prominent longitudinal cracks and micro-pores on the surface. XRD shows a low degree of crystallinity (45%), bigger crystallite size, and even the presence of appreciable amount of non-cellulose matter. FTIR reveals presence of large quantities of hydroxyl, phenolic and aldehyde groups. Component and thermal analyses indicates presence of cellulose and lignin as major components. Physical parameters reveal that, fibres are highly variable in length (range 44-305 mm), and diameter (range 100-795 µm). Mechanical properties of the fibre viz. breaking tenacity, breaking extensibility, specific work of rupture, and coefficient of friction were measured. Microbial decomposition test under soil reveals excellent durability of coconut fibre which makes it appropriate for the application in geotextiles. Mass specific electrical resistance of 4 Ω-kg/m2 indicates its enhanced insulation as compared to the jute.

  13. Statistical Tools Applied in the Characterisation and Evaluation of a Thermo-Hygrometric Corrective Action Carried out at the Noheda Archaeological Site (Noheda, Spain)

    Valero, Miguel Ángel; Merello, Paloma; Navajas, Ángel Fernández; García-Diego, Fernando-Juan


    The Noheda archaeological site is unique and exceptional for its size, and the quality and conservation condition of the Roman mosaic pavement covering its urban pars. In 2008 a tent was installed as protection from rain and sun. Being of interest to characterise the microclimate of the remains, six probes with relative humidity and temperature sensors were installed in 2013 for this purpose. Microclimate monitoring allowed us to check relative humidity differences resulting from the groundwater level, as well as inner sensors reaching maximum temperatures higher than the outdoors ones as a consequence of the non-ventilated tent covering the archaeological site. Microclimatic conditions in the archaeological site were deemed detrimental for the conservation of the mosaics. Thus, in summer 2013, expanded clay and geotextile were installed over the mosaics as a corrective action. The outcomes of this study have proven the effectiveness of this solution to control temperature and relative humidity, helping to configure a more stable microclimate suitable for preservation of the mosaic. PMID:24445414

  14. Potential for localized groundwater contamination in a porous pavement parking lot setting in Rhode Island

    Boving, Thomas B.; Stolt, Mark H.; Augenstern, Janelle; Brosnan, Brian


    The control of polluted surface runoff and the assessment of possible impacts on groundwater is a concern at the local and regional scale. On this background, a study investigates possible impacts of organic and inorganic pollutants (including bacteria) originating from a permeable asphalt parking lot on the water quality immediately beneath it. The functioning of the permeable pavement, including clogging and restricted vertical percolation, was also evaluated. Four nested sample ports (shallow and deep) were installed below low- and high-traffic areas, including one port outside the parking lot. At least initially there was a good hydraulic connection between the parking surface and the shallow sample ports. The presence of a geotextile layer at the base of the parking lot structure, however, was identified in lab tests as one factor restricting vertical percolation to the deeper ports. Clogging of the permeable surface was most pronounced in heavy traffic areas and below snow pile storage areas. Corroborated by high electric conductivity and chloride measurements, sand brought in by cars during winter was the principal cause for clogging. No bacteria or BOD were found in percolating water. Polycyclic aromatic hydrocarbons (PAH) were present at concentrations near minimum detection limit. Nutrients (nitrate and phosphate) were being leached into the ground via the permeable parking lot surface at annual flux rates of 0.45 0.84 g/m2/year. A multi-species tracer test demonstrated a retention capacity of the permeable parking lot structure of >90% for metals and 27% for nutrients, respectively.

  15. Use of leaching chambers for on-site sewage treatment.

    St Marseille, J G; Anderson, B C


    An innovative chamber system was installed for on-site sewage treatment beneath an active parking lot at a restaurant near Cornwall, Ontario. The configuration of this prototype system used polyethylene leaching chambers over which wastewater was allowed to trickle. The chambers were vented to the surface to provide direct, passive air transfer. This demonstration project was examined as a cost-effective wastewater treatment alternative for a very constrained site. The leaching chambers were installed over a geotextile-covered sand filter bed. Chamber sidewall contact contributed an additional 50% to the total soil contact area hence justification for a footprint reduction. A labile carbon source (sawdust) was added into one half of the bed to encourage dissimilatory denitrification. Average hydraulic loading was 50 l m(-1) day(-1) (5 cm day(-1)). Treatment rates exceeded more than 4 orders of magnitude removal for E. coli; 90% biochemical oxygen demand; ammonium; and 99% total phosphorus. Nitrate-N on the carbon-amended side averaged 0.6 mg l(-1) compared with 8.6 mg l(-1) on the (non-carbon) control side. This project has demonstrated that effective on-site treatment can be accomplished. Flow and load equalization, pulse dosing, chamber venting, phosphorus precipitation, and denitrification were keys to treatment success. Applications include domestic and commercial sites.

  16. Proof-of-Concept of the Phytoimmobilization Technology for TNX Outfall Delta: Final Report

    Kaplan, D.I.


    A series of proof-of-principle studies was initiated to evaluate the soil remediation technology, phytoimmobilization, for application at the TNX Outfall Delta (TNX OD) operable unit. Phytoimmobilization involves two steps. The first step is entitled phytoextraction, and it takes place mostly during the spring and summer. During this step the plants extract contaminants from the sediment into the roots and then translocate the contaminants to the aboveground plant parts. The second step is referred to as sequestration and it takes place largely during the autumn and winter when annual plants senesce or deciduous trees drop their leaves. This step involves the immobilization of the contaminant once it leaches form the fallen leaves into a ''geomat,'' a geotextile embedded with mineral sequestering agents. This final report describes the results to date, including those reported in the status report (Kaplan et al. 2000a), those completed since the report was issued, and the preliminary calculations of the phytoimmobilization effectiveness.

  17. 《岩土工程学报》征稿简则


    Loading devices and displacement and stress measurement systems are installed on the geotechnical centrifuge.A centrifugal model in line with the actual stress is established.Considering different conditions, the treatment techniques for new and old roadbeds as well as the improvement efficiency of prestressed pile composite foundation treatment in differential settlement deformation of road widening are studied.The differential deformation features of the widening project and the effectiveness and mechanism of the treatment techniques are simulated.The results show that for the road widening laid with geotextile materials in different strata, although uneven settlement of new and old roadbeds may reduce, the effeciency is not obvious.With the help of reinforced treatment, the lateral displacement of shallow soil greatly decreases, while that of deep soil changes little, indicating that the reinforcement has limited effect on the lateral displacement of soft soil, Using prestressed pipes to handle road widening can control the uneven settlement, greatly accelerate the construction schedule and shorten the construction period, indicating that the composite piled foundation in soft soil is suitable for road widening projects with urgent construction time and high settlement control requirements.The study also shows that the pipe piles produce upward penetration deformation, and due to pile caps and reinforced cushions, the penetration depth is effectively alleviated.

  18. Investigation of the Seismic Performance of Reinforced Highway Embankments

    Toksoy, Y. S.; Edinçliler, A.


    Despite the fact that highway embankments are highly prone to earthquake induced damage, there are not enough studies in the literature concentrated on improving the seismic performance of highway embankments. Embankments which are quite stable under static load conditions can simply collapse during earthquakes due to the destructive seismic loading. This situation poses a high sequence thread to the structural integrity of the embankment, service quality and serviceability. The objective of this study is to determine the effect of the geosynthetic reinforcement on the seismic performance of the highway embankments and evaluate the seismic performance of the geotextile reinforced embankment under different earthquake motions. A 1:50 scale highway embankment model is designed and reinforced with geosynthetics in order to increase the seismic performance of the embankment model. A series of shaking table tests were performed for the identical unreinforced and reinforced embankment models using earthquake excitations with different characteristics. The experimental results were evaluated comparing the unreinforced and reinforced cases. Results revealed that reinforced embankment models perform better seismic performance especially under specificied ground excitations used in this study. Also, the prototype embankment was numerically modelled. It is seen that similar seismic behavior trend is obtained in the finite element simulations.

  19. Attenuation of heavy metals by geosynthetics in the coal gangue-filled columns.

    Wang, Ping; Hu, Zhenqi; Wang, Peijun


    In the subsided areas backfilled with coal gangue, an issue of continuing environmental concern is the migration of hazardous metals to the subsurface soil and groundwater. As an effective isolation material, geosynthetics have been scarcely applied into mining areas reclamation of China. This paper describes research aimed at characterizing the behaviours of different geosynthetics in the leaching columns filled with coal gangues. Four types of geosynthetics were selected: fibres needle-punched nonwoven geotextiles, high-density polyethylene, needle-punched Na-bentonite geosynthetic clay liner (GCL-NP) and Na-bentonite geosynthetic-overbited film. Heavy metals were significantly attenuated and by monitoring aqueous solutions in the whole percolation period, negative correlation was found between pH value and concentration of heavy metals. Generally, GCL-NP showed comparatively better effects on attenuating the migration of heavy metals. According to the meta-analysis of heavy metals present in the leachates and retained in the columns, geosynthetics have good capabilities of sorption and retardation, which can delay the breakthrough time of heavy metals and retard the accumulation in the subsurface. Future research will use X-ray diffraction and micro-imaging (electron microprobe and scanning electron microscopy) to further explain retention mechanisms.

  20. Parameter investigation for decentralised dewatering and solar thermic drying of sludge.

    Wett, B; Demattio, M; Becker, W


    The purpose of this paper is an experimental and model assisted investigation of the capabilities of a dewatering system for sewage sludge for decentralised sites. Laboratory and field tests are performed with different initial conditions and the influences of filter medium, initial height, initial total suspended solids, temperature and relative humidity are discussed. The experimental work shows the feasibility of geotextile media for dewatering high water content sewage sludge and that the textile structure is of secondary importance. The specific filter resistance of the sludge cake is found to be the most significant factor in dewatering applications. The mathematical description of the dewatering process is based on the superposition of two models, the Conventional Filtration Theory for the filtration phase and the BT-model for the drying phase. Feasibility and limits of the theoretical approach are evaluated by means of a comparison between measurements and simulated data of cyclic reloading tests. It is found that a better filtration efficiency is achieved at higher TSS and at lower initial height of the slurry layer. Due to the viscosity decrease, a higher temperature enhances not only evaporation, but also filtration rate.

  1. Hurricane Ike: Field Investigation Survey (Invited)

    Ewing, L.


    much of the storm surge, although there was some overtopping and debris was washed over Seawall Boulevard. In contrast, the geotextile tubes that were in used on Bolivar Peninsula and west Galveston were too low to provide an effective barrier to extreme storm surge or to prevent overtopping. Scour and wave erosion were noticeable for all structures, removing sand from the jetties at Rollover Pass, eroding backfill from the west end of the Galveston Seawall and dislocating toe stone and causing rotation of some geotextile tubes. Material for this presentation draw upon the forthcoming ASCE Report, A Report of Field Observations made 3 - 6 October 2008 and “Field investigation of Hurricane Ike impacts to the upper Texas coast” (Ewing et al. 2009) References ASCE Hurricane Ike Field Investigation Team (in production) A Report of Field Observations made 3 - 6 October 2008; sponsored by Coasts, Oceans, Ports and Rivers Institute and Geotechnical Institute of American Society of Civil Engineers. Ewing, Lesley., Donald K. Stauble, Paul A. Work, Billy L. Edge, Spencer M. Rogers, Mandy U. Loeffler, James M. Kaihatu, Margery Overton, Jeffery P. Waters, Kojiro Suzuki, Robert G. Dean, Marie H. Garrett, Eddie Wiggins, and Garry H. Gregory (2009) “Field Investigation of Hurricane Ike Impacts to the Upper Texas Coast” Shore & Beach, vol. 77(2) 9 - 23.

  2. How effective are soil conservation techniques in reducing plot runoff and soil loss in Europe and the Mediterranean?

    Maetens, W.; Poesen, J.; Vanmaercke, M.


    The effects of soil and water conservation techniques (SWCTs) on annual runoff (Ra), runoff coefficients (RCa) and annual soil loss (SLa) at the plot scale have been extensively tested on field runoff plots in Europe and the Mediterranean. Nevertheless, a comprehensive overview of these effects and the factors controlling the effectiveness of SWCTs is lacking. Especially the effectiveness of SWCT in reducing Ra is poorly understood. Therefore, an extensive literature review is presented that compiles the results of 101 earlier studies. In each of these studies, Ra and SLa was measured on field runoff plots where various SWCTs were tested. In total, 353 runoff plots (corresponding to 2093 plot-years of data) for 103 plot-measuring stations throughout Europe and the Mediterranean were considered. SWCTs include (1) crop and vegetation management (i.e. cover crops, mulching, grass buffer strips, strip cropping and exclosure), (2) soil management (i.e. no-tillage, reduced tillage, contour tillage, deep tillage, drainage and soil amendment) and (3) mechanical methods (i.e. terraces, contour bunds and geotextiles). Comparison of the frequency distributions of SLa rates on cropland without and with the application of SWCTs shows that the exceedance probability of tolerable SLa rates is ca. 20% lower when SWCT are applied. However, no notable effect of SWCTs on the frequency distribution of RCa is observed. For 224 runoff plots (corresponding to 1567 plot-year data), SWCT effectiveness in reducing Ra and/or SLa could be directly calculated by comparing measured Ra and/or SLa with values measured on a reference plot with conventional management. Crop and vegetation management techniques (i.e. buffer strips, mulching and cover crops) and mechanical techniques (i.e. geotextiles, contour bunds and terraces) are generally more effective than soil management techniques (i.e. no-tillage, reduced tillage and contour tillage). Despite being generally less effective, no

  3. Análise comparativa de envoltórios para drenos tubulares em condições de fluxo não-permanente Comparative analysis of envelopes for tubular drains under non-steady state flow conditions

    Denise M. de Almeida


    resistance of the flow and relation between the flowrate and the hydraulic head at 0.55 m drain-soil. The depth of water drained did not show significant difference at 5% probability level; however, the geotextile bidim OP-20 and XT-4 showed the best performance taking into account costs and instalation suitability. In relation to the sediment mass transported, the influence of the wrapper thickness using gravel was observed besides the option of geotextile as excelent filter. The importance of using drain wrappers was demonstrated by comparing the entrance resistance data for the treatments without wrapper (r ent = 0.0102 d m-1 and the 0.15 m gravel treatment (r ent = 0.0032 d m-1, allowing a 68.7% reduction.

  4. Soil intervention as a strategy for lead exposure prevention: The New Orleans lead-safe childcare playground project

    Mielke, Howard W., E-mail: [Department of Chemistry, Tulane University, New Orleans, LA 70118 (United States); Center for Bioenvironmental Research at Tulane and Xavier Universities, 1430 Tulane Avenue SL-3, New Orleans, LA 70112 (United States); Covington, Tina P. [Charity School of Nursing, Delgado Community College, New Orleans, LA 70112-1397 (United States); College of Nursing, University of South Alabama, Doctor of Nursing Practice Program (student), Mobile AL 36688-0002 (United States); Mielke, Paul W. [Department of Statistics, Colorado State University, Fort Collins, CO 80523-1877 (United States); Wolman, Fredericka J. [Director of Pediatrics, Department of Children and Families, State of Connecticut, Hartford, CT 06473 (United States); Powell, Eric T.; Gonzales, Chris R. [Lead Lab, Inc., New Orleans, LA 70179-1125 (United States)


    The feasibility of reducing children's exposure to lead (Pb) polluted soil in New Orleans is tested. Childcare centers (median = 48 children) are often located in former residences. The extent of soil Pb was determined by selecting centers in both the core and outlying areas. The initial 558 mg/kg median soil Pb (range 14-3692 mg/kg) decreased to median 4.1 mg/kg (range 2.2-26.1 mg/kg) after intervention with geotextile covered by 15 cm of river alluvium. Pb loading decreased from a median of 4887 {mu}g/m{sup 2} (454 {mu}g/ft{sup 2}) range 603-56650 {mu}g/m{sup 2} (56-5263 {mu}g/ft{sup 2}) to a median of 398 {mu}g/m{sup 2} (37 {mu}g/ft{sup 2}) range 86-980 {mu}g/m{sup 2} (8-91 {mu}g/ft{sup 2}). Multi-Response Permutation Procedures indicate similar (P-values = 0.160-0.231) soil Pb at childcare centers compared to soil Pb of nearby residential communities. At {approx}$100 per child, soil Pb and surface loading were reduced within hours, advancing an upstream intervention conceptualization about Pb exposure prevention. - Highlights: > Upstream thinking refers to attending to causative agents that affect outcomes. > New Orleans has a high density soil Pb map of all residential communities. > Many childcare centers are located in Pb polluted residential communities. > Evaluation of childcare center playground soils substantiated severe Pb pollution. > Pursuing upstream thinking, low Pb soil was put on playgrounds to protect children. - Within hours, at a cost of about U.S. $100 (2010) per child, it is feasible to transform exterior play areas at childcare centers from Pb contaminated to Pb-safe with a large margin of safety.

  5. Physical properties and hydrological response of green roof substrates based on recycled construction materials

    Vanwalleghem, Tom; Hayas, Antonio; Jiménez-Quiñones, Daniel; Peña, Adolfo; Giráldez, Juan Vicente


    Green roofs in urban areas improve the building's energy efficiency and provide a wide array of additional environmental benefits. Characterizing and predicting the physical properties and hydrological response of green roofs is necessary to understand the roof's heat balance, which is controlled to a large extent by the substrate's water content, to predict the runoff response and functioning as a part of sustainable urban drainage systems and to plan irrigation of the plants in drier climates. This study examines 10 different extensive green roof substrates, based on recycled construction materials. Green roof simulation decks were installed in boxes of 0,6 m x 0,4 m to a depth of 70 mm, 10 with and 10 without plants. Total water holding capacity of the substrates varied between 10,4 - 23,9 %, with an additional 19 % retained by the drainage layer and geotextiles used in the simulation deck. An important compaction of 30 % on average was observed after 1,5 months. Final bulk densities are between 1457 - 1993 kg m-3. In an evaporation experiment, it was shown that the water evaporated from the green roofs is controlled mainly by the relative moisture content. Substrate properties exerted only a secondary control, with the lowest evaporation rates from the substrates with highest coarse crushed aggregate content and with the highest clay content. The evaporation model proposed here was shown to work well to simulate the evolution of the water balance and therefore the specific unit weight over longer time periods in all substrates, with a Nash-Sutcliffe model efficiency of 0.989. Finally, plants were found to grow satisfactorily in all substrates. Therefore, when regular irrigation is provided, it was concluded that green roofs based on recycled construction materials are a viable option. Future research will have to explore the long-term plant dynamics under water-limited conditions.

  6. Marine microbial community response to inorganic and organic sediment amendments in laboratory mesocosms.

    Kan, Jinjun; Wang, Yanbing; Obraztsova, Anna; Rosen, Gunther; Leather, James; Scheckel, Kirk G; Nealson, Kenneth H; Arias-Thode, Y Meriah


    Sediment amendments provide promising strategies of enhancing sequestration of heavy metals and degradation of organic contaminants. The impacts of sediment amendments for metal and organic remediation including apatite, organoclay (and apatite and organoclay in geotextile mats), acetate, and chitin on environmental microbial communities in overlying water and sediment profiles are reported here. These experiments were performed concurrent with an ecotoxicity evaluation (data submitted in companion paper) and X-ray absorption spectroscopy of zinc speciation post apatite amendments. X-ray absorption spectra showed that a modest modification of zinc speciation occurred in amended treatments. Significant changes in both bacterial cell densities and populations were observed in response to amendments of apatite+organoclay, chitin, and acetate. The enriched bacteria and breakdown of these amendments were likely attributed to water quality degradation (e.g. ammonia and dissolved oxygen). Molecular fingerprints of bacterial communities by denaturant gradient gel electrophoresis (DGGE) showed that distinct bacterial populations occurred in overlying waters from different amendments: apatite+organoclay led to the dominance of Gammaproteobacteria, acetate enriched Alphaproteobacteria, and chitin treatment led to a dominance of Bacteroidetes and Alphaproteobacteria. In amended sediments, Firmicutes, Bacteroidetes, and Deltaproteobacteria (Desulfovibrio) were commonly found with chitin and apatite+chitin treatments. Finally, sulfate-reducing bacteria (e.g. Desulfovibrio) and metal-reducing bacteria were also recovered with most probable number (MPN) analyses in treatments with acetate, chitin, and apatite+chitin. These geochemically important bacteria were stimulated by amendments and may play critical functional roles in the metal and organic contaminant remediation process for future investigations of contaminated sediments.

  7. Mitigation of the surficial hydrogeological impact induced by the construction of the Pajares Tunnels (NW Spain).

    Valenzuela, Pablo; Sáenz de Santa María, José Antonio; José Domínguez-Cuesta, María; López Fernández, Carlos; Meléndez-Asensio, Mónica; Jiménez-Sánchez, Montserrat


    Pajares Tunnels are railway tunnels 24.5 km long and 700 m depth drilled in Paleozoic rocks of the Cantabrian Range (NW Spain). The construction of these tunnels is the cause of a very important surficial hydrogeological impact on the Alcedo Valley consisting on: i) the strong alteration of its natural hydrogeological regime; ii) the development of 25 sinkholes from 2007 to 2014 in calcareous rocks covered by alluvial deposits; iii) the transformation of the Alcedo stream into an influent, losing all the surficial water flow by infiltration trough 7 active ponors developed at the stream bed. The estimated mean water volume infiltration across these sinkholes was around 0.4 Hm3/year (10 ls-1). Previous studies proved the infiltration of this runoff towards the new base level established by the tunnels, which would affect the operation and safety conditions required in a high-speed railway line. In order to minimize this situation, several geotechnical works have been performed from July 2014 to November 2015. These works consist on: (i) geological research, (ii) borehole drilling, (iii) geophysical prospecting, (iv) sealing of sinkholes and ponors, (v) construction of a concrete channel covered with geotextile and completely buried with original removed alluvial materials, and (vi) environmental restoration. After the completion of these actions, the first observations have allowed to note a total elimination of the infiltration from the Alcedo Valley to the tunnels. This involves an 8% reduction of total drainage in Pajares Tunnels (from average 350 l s-1 to 325 l s-1).

  8. Mitigation of turbidity currents in reservoirs with passive retention systems: validation of CFD modeling

    Ferreira, E.; Alves, E.; Ferreira, R. M. L.


    Sediment deposition by continuous turbidity currents may affect eco-environmental river dynamics in natural reservoirs and hinder the maneuverability of bottom discharge gates in dam reservoirs. In recent years, innovative techniques have been proposed to enforce the deposition of turbidity further upstream in the reservoir (and away from the dam), namely, the use of solid and permeable obstacles such as water jet screens , geotextile screens, etc.. The main objective of this study is to validate a computational fluid dynamics (CFD) code applied to the simulation of the interaction between a turbidity current and a passive retention system, designed to induce sediment deposition. To accomplish the proposed objective, laboratory tests were conducted where a simple obstacle configuration was subjected to the passage of currents with different initial sediment concentrations. The experimental data was used to build benchmark cases to validate the 3D CFD software ANSYS-CFX. Sensitivity tests of mesh design, turbulence models and discretization requirements were performed. The validation consisted in comparing experimental and numerical results, involving instantaneous and time-averaged sediment concentrations and velocities. In general, a good agreement between the numerical and the experimental values is achieved when: i) realistic outlet conditions are specified, ii) channel roughness is properly calibrated, iii) two equation k - ɛ models are employed iv) a fine mesh is employed near the bottom boundary. Acknowledgements This study was funded by the Portuguese Foundation for Science and Technology through the project PTDC/ECM/099485/2008. The first author thanks the assistance of Professor Moitinho de Almeida from ICIST and to all members of the project and of the Fluvial Hydraulics group of CEHIDRO.

  9. Laboratory-based experiments to investigate the impact of glyphosate-containing herbicide on pollution attenuation and biodegradation in a model pervious paving system.

    Mbanaso, F U; Coupe, S J; Charlesworth, S M; Nnadi, E O


    An experimental investigation was carried out to determine the effect of glyphosate-containing herbicides (GCHs) on the hydrocarbon retention and biodegradation processes known to occur in pervious pavement systems (PPSs). The PPS test rigs were based on the four-layered design detailed in CIRIA C582. This enabled the pollutant retention capacity of the PPS and biodegradation of retained pollutants by microorganisms to be investigated. The use of test rigs also enabled the impact of GCH on PPS eukaryotic organisms to be studied, by the monitoring of protist bioindicators. Results showed that GCH disrupted hydrocarbon retention by the geotextiles relative to rigs with mineral oil only added, as 9.3% and 24.5% of added hydrocarbon were found in herbicide only rigs and herbicide plus oil rigs respectively. In previous studies, PPS contaminated by mineral oil had been shown to retain 98.7% of added oils and over several weeks, biodegrade this oil in situ. Where GCH was added to experimental models, much higher concentrations of heavy metals, including Pb, Cu, and Zn, were released from the PPS in effluent, particularly where GCH and mineral oil were added together. The source of the majority of the metal contamination was thought to be the used engine oil. The herbicide generally increased the total activity of microbial communities in rig systems and had a stimulating effect on bacterial and fungal population numbers. Although the protists, which are part of the microbial community directly or indirectly responsible for biodegradation, were initially strongly affected by the herbicide, they showed resilience by quickly recovering and increasing their population compared with rigs without added herbicide, including the rigs with mineral oil added to them. However, the presence of herbicide was associated with a decrease in the species richness of recorded protist taxa and a predominance of robust, cosmopolitan or ubiquitous protist genera.

  10. Remediation of PCB contaminated soils in the Canadian Arctic: excavation and surface PRB technology.

    Kalinovich, Indra; Rutter, Allison; Poland, John S; Cairns, Graham; Rowe, R Kerry


    The site BAF-5 is located on the summit of Resolution Island, Nunavut, just southeast of Baffin Island at 61 degrees 35'N and 60 degrees 40'W. The site was part of a North American military defense system established in the 1950s that became heavily contaminated with PCBs during and subsequent, its operational years. Remediation through excavation of the PCB contaminated soil at Resolution Island began in 1999 and at its completion in 2006 approximately 5 tonnes of pure PCBs in approximately 20,000 m3 of soil were remediated. Remediation strategies were based on both quantity of soil and level of contamination in the soil. Excavation removed 96% of the PCB contaminated soil on site. In 2003, a surface funnel-and-gate permeable reactive barrier was design and constructed to treat the remaining contamination left in rock crevices and inaccessible areas of the site. Excavation had destabilized contaminated soil in the area, enabling contaminant migration through erosion and runoff pathways. The barrier was designed to maximize sedimentation through settling ponds. This bulk removal enabled the treatment of highly contaminated fines and water through a permeable gate. The increased sediment loading during excavation required both modifications to the funnel and a shift to a more permeable, granular system. Granulated activated charcoal was chosen for its ability to both act as a particle retention filter and adsorptive filter. The reduction in mass of PCB and volume of soils trapped by the funnel of the barrier indicate that soils are re-stabilizing. In 2007, nonwoven geotextiles were re-introduced back into the filtration system as fine filtering could be achieved without clogging. Monitoring sites downstream indicate that the barrier system is effective. This paper describes the field progress of PCB remediation at Resolution Island.

  11. The effectiveness of jute and coir blankets for erosion control in different field and laboratory conditions

    Kalibová, Jana; Jačka, Lukáš; Petrů, Jan


    Vegetation cover is found to be an ideal solution to most problems of erosion on steep slopes. Biodegradable geotextiles (GTXs) have been proved to provide sufficient protection against soil loss in the period before vegetation reaches maturity, so favouring soil formation processes. In this study, 500 g m-2 jute (J500), 400 g m-2 (C400), and 700 g m-2 coir (C700) GTXs were first installed on a 9° slope under "no-infiltration" laboratory conditions, then on a 27° slope under natural field conditions. The impact of GTXs on run-off and soil loss was investigated to compare the performance of GTXs under different conditions. Laboratory run-off ratio (percentage portion of control plot) equalled 78, 83, and 91 %, while peak discharge ratio equalled 83, 91, and 97 % for J500, C700, and C400 respectively. In the field, a run-off ratio of 31, 62, and 79 %, and peak discharge ratio of 37, 74, and 87 % were recorded for C700, J500, and C400 respectively. All tested GTXs significantly decreased soil erosion. The greatest soil loss reduction in the field was observed for J500 (by 99.4 %), followed by C700 (by 97.9 %) and C400 (by 93.8 %). Irrespective of slope gradient or experimental condition, C400 performed with lower run-off and peak discharge reduction than J500 and C700. The performance ranking of J500 and C700 in the laboratory differed from the field, which may be explained by different slope gradients, and also by the role of soil, which was not included in the laboratory experiment.

  12. Abandoned deep mine subsidence investigation and remedial design, Interstate 70, Guernsey County, Ohio

    Hoffmann, A.G.; Clark, D.M.; Bechtel, T.D.


    A two thousand linear foot, undermined section of Interstate 70 in Guernsey County, Ohio experienced settlements due to pothole type subsidence events within the travel lanes, shoulders and adjacent right-of-way areas. Potholes measured approximately ten feet in depth and width. The subsidence occurred after the dewatering of the abandoned deep mine during auger mining operations west of the site. A two-phase emergency investigation was undertaken by the Ohio Department of Transportation (ODOT) and Gannett Fleming Cord dry and Carpenter (GF). The purpose of the investigation was to assess the immediate danger of potholes occurring in the traveled lanes and paved shoulders, to identify the subsidence mechanisms, and to design a remediation program. Phase one investigations involved the review of existing subsurface data, the advancement of shallow borings and the performance of multiple geophysical surveys including ground penetrating radar, seismic refraction and electromagnetic terrain conductivity. The Phase one investigations did not reveal the presence of subsidence voids. Phase two investigations included borings to the mine level and videotaping of mine conditions. The mine was found to be completely flooded. Based upon the collected data, two mechanisms of failure, localized roof fall and piping of overburden soils into the mine void, were identified. Two remedial alternatives, (1) the filling of the mine void, and (2) the reinforcement of the highway using geotextiles, were evaluated, Filling of the mined interval and grouting of overburden bedrock fractures and voids, within a limited area, were selected. Construction plans, specifications and cost estimates were prepared for bidding and award. During the bidding process, a catastrophic, pothole type failure of the I-70 travel lanes occurred. The interstate was closed and the planned remediation activities were performed as an emergency project. The mine interval was grouted and portions of the highway

  13. Chosing erosion control nets. Can't you decide? Ask the lab.

    Simkova, Jana; Jacka, Lukas


    Geotextiles (GTXs) have been used to protect steep slopes against soil erosion for about 60 years and many products have become available. The choice of individual product is always based on its ratio of cost versus effectiveness. Generally applicable recommendations for specific site conditions are missing and testing the effectiveness of GTXs in the field is time consuming and costly. Due to various site conditions, results of numerous case-studies cannot be generalized. One of the major and site-specific factors affecting the erosion process, and hence the effectiveness of GTXs, is the soil. This study aimed to determine the rate of influence of three natural erosion control nets on the volume and velocity of surface runoff caused by rainfall. The nets were installed on slope under laboratory conditions and then exposed to simulated rainfall. An impermeable plastic film was used as a substrate instead of soil to simulate non-infiltrating conditions. A comparison of the influence of tested GTX samples on surface runoff may indicate to their erosion control effect. Thus, the results could help with choosing a particular product. Under real conditions, the effect of erosion control nets would be increased by the infiltration capacity of the soil, equally for all samples. Therefore, the order of effectiveness of the samples should stay unchanged. To validate this theory, a field experiment was carried out where soil loss was recorded along with runoff characteristics. The data trends of discharge culmination under natural conditions were similar to trends under laboratory conditions and corresponded to soil loss records.

  14. Creativity in action: elegantly simple idea puts firm on international pipeline map

    Podlubny, J.


    A saddle bag-like device, a relatively simple invention to carry weights to hold pipelines stable in wet environments, has catapulted a small Athabasca, Alberta, company to international prominence. The saddle bag is made of 100 per cent non-biodegradable material called geotextile, commonly referred to as road matting. The bags have a life expectancy of 100 years or more, easily outlasting the pipe they protect from shifting. Weighting systems are used on pipelines to achieve the negative buoyancy required to prevent them from floating out of wet ground. They are essential in wide swats of the northern areas where the oil and gas industry operates. The saddle bags replace the traditional concrete weights which have been either bolted down or set on top of the pipe. They were bulky and hard to transport, as well as difficult to place on the pipe. In contrast, the saddle bags are easy to transport and easy to install. Indeed, the production process is portable, so that the weighted saddle bags can be made at the site of the pipeline construction job involved. This makes it easier to do pipeline weighting jobs in cold weather, at remote locations or in spots where considerable travel time is involved in completing projects. Saddle Tech has recently joined forces with the giant in the weighting system world from the United States, CRC-Evans. The U.S. firm is marketing the bags under a trademarked name 'the saddle bag'. The product being used on projects in California, as well as on almost 90 per cent of wetlands pipeline work in Alberta and British Columbia. Production was 17,000 bags in the first year of operation. So far this season, more than 40,000 bags have been made and distributed throughout North America. Plans are afoot to expand and convert the production facility to an automated operation, running 24 hours a day.

  15. Use of geosynthetics for performance enhancement of earth structures in cold regions

    Jie Han; Yan Jiang


    Earth structures, such as roadways, embankments and slopes, and earth retaining walls, have been commonly used in cold regions for transportation and other applications. In addition to typical design considerations for earth structures at normal temperature, a design must also consider the unique problems associated with low temperature, such as frost heave, lateral expansion, thaw settlement and weakening, and degradation of material properties. Geosynthetics have been used in cold regions to stabilize earth structures during construction and mitigate potential problems during their service at low tem-perature. This paper provides a state of practice review of the use of geosynthetics for performance enhancement of earth structures in cold regions. This paper starts with basic information on available geosynthetic products and their functions, evaluates properties and behavior of geosynthetics and soil-geosynthetic systems at low temperature, and discusses past studies and their key results on the use of geosynthetics to enhance the performance of roadways, embankments, and earth retaining walls in cold regions. This review reveals that geosynthetics at low temperature have higher tensile strength and stiffness, lower creep rate, and lower elongation at failure. The effect of temperature becomes significant when nonwoven geotextiles are subjected to moistening and soil intrusion at subfreezing temperature. Freeze-thaw cycles may degrade hydraulic and mechanical properties of geosynthetic-soil systems. The inclusion of geosynthetics in soil provides drainage and/or barrier to water flow, retains mechanical properties, and reduces frost heave during and after freeze-thaw cycles. Effectiveness of geosynthetics has been confirmed in the field in bridging over voids, stabilizing roadways over temper-ature-susceptible soils during thaw, and proving drainage and barrier to temperature-susceptible soils before freeze. To avoid frost heave and lateral expansion of backfill

  16. Clogging evaluation of porous asphalt concrete cores in conjunction with medical x-ray computed tomography

    Su, Yu-Min; Hsu, Chen-Yu; Lin, Jyh-Dong


    This study was to assess the porosity of Porous Asphalt Concrete (PAC) in conjunction with a medical X-ray computed tomography (CT) facility. The PAC was designed as the surface course to achieve the target porosity 18%. There were graded aggregates, soils blended with 50% of coarse sand, and crushed gravel wrapped with geotextile compacted and served as the base, subbase, and infiltration layers underneath the PAC. The test site constructed in 2004 is located in Northern of Taiwan in which the daily traffic has been light and limited. The porosity of the test track was investigated. The permeability coefficient of PAC was found severely degraded from 2.2×10-1 to 1.2×10-3 -cm/sec, after nine-year service, while the permeability below the surface course remained intact. Several field PAC cores were drilled and brought to evaluate the distribution of air voids by a medical X-ray CT nondestructively. The helical mode was set to administrate the X-ray CT scan and two cross-sectional virtual slices were exported in seconds for analyzing air voids distribution. It shows that the clogging of voids occurred merely 20mm below the surface and the porosity can reduce as much about 3%. It was also found that the roller compaction can decrease the porosity by 4%. The permeability reduction in this test site can attribute to the voids of PAC that were compacted by roller during the construction and filled by the dusts on the surface during the service.

  17. Predicting physical clogging of porous and permeable pavements

    Yong, C. F.; McCarthy, D. T.; Deletic, A.


    SummaryPorous pavements are easily retrofitted, and effective in improving water quality and hydrology, but prone to clogging. Despite being a major determinant in the lifespan of porous pavements, there is limited information on the physical clogging processes through these systems. The aim of this study was to understand the main physical processes that govern physical clogging and develop a simple black-box model that predicts physical clogging. The key variables that were hypothesised to influence clogging were pavement design and climate characteristics. Two compressed time scale laboratory experiments were conducted over 3 years on three common porous pavement types; monolithic porous asphalt, modular Hydrapave and monolithic Permapave. Pavement design was found to be an important role in clogging. Permapave did not clog even after 26 years of operation in simulated sub-tropical Brisbane (Australia) climate while porous asphalt and Hydrapave clogged after just 12 years, from surface clogging and geotextile clogging, respectively. Each system was tested using two different dosing patterns: (1) continual wetting with no dry periods and (2) variable inflow rates with drying periods (i.e. representing more natural conditions). The latter dosing method approximately doubled the lifespan of all systems suggesting the influence of climate conditions on clogging. Clogging was found to be highly correlated with cumulative volume and flow rate. A simple black-box regression model that predicts physical clogging was developed as a function of cumulative volume and Brisbane climatic conditions. However it is very likely that the shape of this regression is general, and that it could be calibrated for different climates in the future.

  18. Reinforcing of deposit slopes of Xiaowan Hydropower Station and application of prestressed anchorage cables%小湾水电站堆积体边坡支护与锚索技术应用

    张德圣; 姜玉松; 吴诗勇


    With regard to the deposit slopes of Xiaowan Hydropower Station, the relevant reinforcing measures were analyzed, and the application of prestressed anchorage cables was highlighted. The results indicate that the slope reinforcements in the study area comprehensively adopt engineering protection and ecological protection techniques. The pre-stressing anchorage cables are the principal part of the engineering, and their drilling and grouting are the difficulty and keystone of the anchorage technology. The technology of concentric drilling and eccentric drilling with pipes can availably solve boring problem. By wrapping geotextile and thin canvas outside the prestressed steel strand, it can make concrete calculi protect steel strand of tensile section and reduce grouting quantity so as to avoid grouting waste.%分析小湾水电站堆积体边坡支护措施,研究预应力锚索技术的应用.分析认为,研究区边坡支护综合运用了工程护坡和生态护坡等边坡处理技术,预应力锚索是其主体工程,锚索孔钻孔和灌浆是该技术应用中的难点和重点,使用偏心跟管钻进技术和同心跟管钻进技术能有效解决钻孔难以成孔的问题;通过在锚索体外裹土工布和细帆布的方法,既保证了水泥结石对自由段锚索体的保护,又减少了浆量损耗,避免浆体浪费.

  19. Elasticity Modulus and Flexural Strength Assessment of Foam Concrete Layer of Poroflow

    Hajek, Matej; Decky, Martin; Drusa, Marian; Orininová, Lucia; Scherfel, Walter


    Nowadays, it is necessary to develop new building materials, which are in accordance to the principles of the following provisions of the Roads Act: The design of road is a subject that follows national technical standards, technical regulations and objectively established results of research and development for road infrastructure. Foam concrete, as a type of lightweight concrete, offers advantages such as low bulk density, thermal insulation and disadvantages that will be reduced by future development. The contribution focuses on identifying the major material characteristics of foam concrete named Poroflow 17-5, in order to replace cement-bound granular mixtures. The experimental measurements performed on test specimens were the subject of diploma thesis in 2015 and continuously of the dissertation thesis and grant research project. At the beginning of the contribution, an overview of the current use of foam concrete abroad is elaborated. Moreover, it aims to determine the flexural strength of test specimens Poroflow 17-5 in combination with various basis weights of the underlying geotextile. Another part of the article is devoted to back-calculation of indicative design modulus of Poroflow based layers based on the results of static plate load tests provided at in situ experimental stand of Faculty of Civil Engineering, University of Žilina (FCE Uniza). Testing stand has been created in order to solve problems related to research of road and railway structures. Concern to building construction presents a physical homomorphic model that is identical with the corresponding theory in all structural features. Based on the achieved material characteristics, the tensile strength in bending of previously used road construction materials was compared with innovative alternative of foam concrete and the suitability for the base layers of pavement roads was determined.

  20. 东湖隧道钢板桩围堰施工质量控制%East Lake Tunnel Steel Sheet Pile Cofferdam Construction Quality Control



    East Lake along the tunnel to cut down construction,before the construction of the main structure of the middle of the lake to be formed to build a steel sheet pile cofferdam construction site,steel sheet pile cofferdam construction quality not only to the middle of the lake tunnel structure construction cost and duration,is also related to post-construction security,its significance is huge.Paper first describes the overview of the East Lake Tunnel steel cofferdam and structural characteristics;second illustrates the steel sheet pile cofferdam construction process;last from the Material Control,Surveying,steel sheet pile into,laying geotextile,filling the soil within the weir and cofferdam deformation monitoring point of view on the impact of cofferdam construction quality of technical points.%东湖隧道采取明挖顺作法施工,湖中段主体结构施工前须构筑钢板桩围堰形成施工场地,钢板桩围堰施工质量不仅关系到湖中段隧道结构施工成本与工期,更关系到后期施工安全,其意义巨大。介绍了东湖隧道钢围堰工程概况与结构特点,阐明了钢板桩围堰施工工艺流程,并从材料控制、测量放线、钢板桩打入、土工布铺设、堰内土体填筑和围堰变形监测等角度论述了影响围堰施工质量的技术要点。

  1. Modified gradient ratio (GR) test system with micro pore pressure transducer measurement%结合微孔隙水压力计改良型GR试验系统分析研究

    张达德; 郦能惠; 陈柏麟; 傅新民


    本研究针对结合微孔隙水压力计改良型GR试验系统与一般GR试验系统进行了一系列的试验分析比较,研究中所使用的试验材料包含4种不同针轧不织布及5种不同比例渥太华砂与风化泥岩混合土壤.试验结果发现,由改良型GR试验系统所得的GR试验值都高于一般GR试验系统所得结果,同时也验证了微孔隙水压力计在GR试验系统中可提供较好的孔隙水压力量测与抗阻塞潜势评估.%A series of gradient ratio (GR) tests with conventional GR test device, modified implanted GR test device with and without micro pore pressure transducers were done. 4 different types of needle-punched nonwoven geotextiles and 5 mixtures of Ottawa sand and weathered mudstone with various percentages were used as testing materials. It was found that the GR values from modified GR tests are generally greater than that obtained from the conventional GR tests. It is believed the transducers installed in the GR test systems provide better measurement on pore pressure distribution and better evaluation of the clogging potential.

  2. Protective effect of overlying geosynthetic on geomembrane liner observed from landfill field tests and inclined board laboratory experiments.

    Chung, Moonkyung; Seo, Min Woo; Kim, Kang Suk; Park, Jun Boum


    Geosynthetic liner systems are generally installed in landfill sites to prevent toxic leachate from escaping into the adjoining environment by utilizing their impervious characteristics. Therefore, it is important to protect the geomembrane from being damaged or destroyed during all phases of landfilling, namely landfill construction, waste tipping and landfill closure. This paper presents firstly the observed performance of a geomembrane liner from a landfill site where the geomembrane liner was installed on the slopes of a Korean landfill; and secondly the results of an inclined board laboratory test. Two types of experiments were conducted to identify the protecting effect of the overlaying geosynthetic on the geomembrane liners. At a testing landfill site, the slope consisted of three different sub-inclines and two 2-m-wide intermediate levels. The sub-inclines were each 8 m in vertical height and their angle of inclination was 1: 1.5 (vertical: horizontal). The reported observations were made for a time period of approximately 1 year, until the landfill was filled with wastes to the top of the uppermost slope. In addition, inclined board laboratory tests were carried out. During the inclined board test, a base table is inclined slowly and steadily until the block located on the base table starts to slide, when the tension and displacements of two geosynthetics, namely the geomembrane liner and protecting geotextile, are measured. In conclusion, test results showed that the down-drag force generated by waste accumulation and sliding of upper material was to a large extent dissipated through the elongation of the protecting geosynthetic overlying the geomembrane and thus was not transferred to the geomembrane. Unless the protecting geosynthetic undergoes structural failure, this stress relaxation phenomenon continues to occur so that the magnitude of tensile force to be applied on the geomembrane remains marginal.

  3. Reabilitation of degraded area by erosion, using soil bioengineering techniques in Bacanga river basin, Sao Luis City - Maranhao State, Brazil.

    Teixeira Guerra, A. J.; Rodrigues Bezerra, J. F.; da Mota Lima, L. D.; Silva Mendonça, J. K.; Vieira Souza, U. D.; Teixeira Guerra, T.


    dominant vegetal cover adjacent to the urban gullies. The local climate is humid tropical, with average annual temperatures of 26°C, reaching higher values in October to December and lower from April to June. Rainfall distribution throughout the year is irregular, marked by two very distinct seasons (rainy and dry). The highly seasonal erosive rains incise a complex series of soil erosion landforms, mainly gullies in this area. The following procedures have been carried out: fieldwork with monitoring of gully head erosion; Environmental Education Program; handcraft workshop regarding the prodution of geotextiles from Buriti fiber. The rehabilitation of this degraded site, follows these stages: 1. Acquisition of equipment and materials; 2. Contracting workers; 3. Reshaping selected gully walls; 4. Adding organic palm materials to the topsoil and ~30 kg of grass seeds; 5. Application of geotextile anchored on the ground by using wooden stakes; 6. Maintenance work with photographic records; 7. Photo comparison to measure the vegetal cover percentage, with the aid of geoprocessing software. Some of the gully walls presented steep slopes, around 90 degrees, and therefore, it was necessary to reshape them for the application of soil bioengineering techniques. It was selected a sample area of 2.000 m2 to be rehabilitated. The knowledge of soil and geomorphological characteristics was essential to understand surface runoff, considering the direction of water flows. Due to the difficulties in diverting the flows, which would require more extensive engineering works, the channel was maintained, and the base of the slopes was strengthened to support the flows. In the upper part of this area, which had ~8° slope angle, contour lines were surveyed and barriers of wooden stakes were used to retard runoff velocity from adjacent vegetated slopes. Some slopes in this part had a 45° slope angle, due to the local topography. However, this angle is considered too steep for the application

  4. Development and field testing of an alternative latrine design utilizing basic oxygen furnace slag as a treatment media for pathogen removal

    Stimson, J.; Suhogusoff, A. V.; Blowes, D. W.; Hirata, R. A.; Ptacek, C. J.; Robertson, W. D.; Emelko, M. B.


    In densely-populated communities in developing countries, appropriate setback distances for pit latrines often cannot be met. An alternative latrine was designed that incorporates two permeable reactive media to treat pathogens and nitrate from effluent. Basic oxygen furnace (BOF) slag in contact with wastewater effluent elevates pH to levels (> 11) that inactivate pathogens. Saturated woodchip creates reducing conditions that encourage the growth of denitrifying bacteria which remove NO3-. The field application was constructed in Santo Antônio, a peri-urban community located 25 km south of the city of São Paulo, Brazil. A 2-m diameter pit was excavated to a depth of 4 m into the sandy-clay unsaturated zone. A geotextile liner was emplaced to create saturated conditions in the 0.5-m thick woodchip barrier. Above the woodchip barrier, a 1-m thick layer of BOF slag mixed with pea gravel and sand was emplaced. A series of filter layers, grading upward from coarse sand to fine gravel, where placed above the BOF layer, and gravel was also infilled around the outer perimeter of the excavation, to ensure O2 diffusion into the design, the formation of biofilm, and degradation of organic material. A control latrine, constructed with similar hydraulic characteristics and nonreactive materials, was constructed at a locality 100 m away, in the same geological materials. Total coliform, thermotolerant coliform, and E. coli are removed by approximately 4-5 log concentration units in less than one meter of vertical transport through the BOF slag media. In the control latrine, comparable reductions in these pathogenic indicators are observed over three meters of vertical transport. Removal of sulphur-reducing Clostridia, Clostridium perfrigens and somatic coliphage are also achieved in the alternative design, but initial concentrations in effluent are low. Some measurable concentrations of pathogen indicators are measured in lysimeters below the BOF layer, but are associated

  5. Performance of a constructed fen peatland: Reclamation of oil sands landscapes

    Price, J. S.


    improve upland function. Water quality issues related to the transport of residual process water in the tailings sand are part of the design. Initially these are less problematic than sediment entering the fen due to the overland flow caused by the large snowmelt and several extreme rainfall events that have occurred. The modifications to the upland, and a suite of sediment-trapping geotextile logs, will reduce the sediment issue. Monitoring continues.

  6. The plot size effect on soil erosion on rainfed agriculture land under different land uses in eastern Spain

    Cerdà, A.; Bodí, M. B.; Burguet, M.; Segura, M.; Jovani, C.


    Soil erosion at slope scale is dependent on the size of the plot. This is because soil erosion is a scale-dependent process due to the spatial variability in infiltration, the potential for sediment to be captured by vegetation and other roughness components, and the changes in erosion rates and processes with increasing amounts of runoff. The effects of plot size may also vary with land use, as plot size may be less important in areas with a more homogeneous plant cover or bares soils; meanwhile the soil transmission losses will higher on vegetation covered soils and on patchy distributed plants. A series of study plots were established in 2003 at the El Teularet experimental Station in the Sierra de Enguera in eastern Spain. The overall goal is to assess runoff and erosion rates from different land uses at different spatial scales. Thirteen sets of plots have been established, and each set consists of five adjacent plots that vary in size from 1 m2 (1 x 1 m), 2 m2 (1 x 2 m), 4 m2 (1 x 4 m), 16 m2 (2 x 8 m) and 48 m2 (3 m wide x 16 m length). Each set of plots has a different land use, and the land uses being tested in the first year of this study are fallow, ploughed but unplanted, untilled oats and beans, tilled oats and beans, straw mulch, mulched with chipped olive branches, a geotextile developed to control erosion on agricultural fields, scrub oaks (Quercus coccifera), gorse (Ulex parviflorus), and three herbicide treatments—a systemic herbicide, a contact herbicide, and a persistent herbicide. From those plots, three plots were selected to analyse the effect of the size of the plot on the soil erosion assessment. Herbicide (bare), Catch crops (oat) and scrubland were selected to analyze the soil losses during 2004 and 2005. The results shows that sediment delivery is highly dependent on the land use and land management as the scrubland contributed with null sediment yield, meanwhile the herbicide reached the largest soil loss. The soil erosion was higher

  7. Environmental and health effects of nanomaterials in nanotextiles and façade coatings.

    Som, Claudia; Wick, Peter; Krug, Harald; Nowack, Bernd


    Engineered nanomaterials (ENM) are expected to hold considerable potential for products that offer improved or novel functionalities. For example, nanotechnologies could open the way for the use of textile products outside their traditional fields of applications, for example, in the construction, medical, automobile, environmental and safety technology sectors. Consequently, nanotextiles could become ubiquitous in industrial and consumer products in future. Another ubiquitous field of application for ENM is façade coatings. The environment and human health could be affected by unintended release of ENM from these products. The product life cycle and the product design determine the various environmental and health exposure situations. For example, ENM unintentionally released from geotextiles will probably end up in soils, whereas ENM unintentionally released from T-shirts may come into direct contact with humans and end up in wastewater. In this paper we have assessed the state of the art of ENM effects on the environment and human health on the basis of selected environmental and nanotoxicological studies and on our own environmental exposure modeling studies. Here, we focused on ENM that are already applied or may be applied in future to textile products and façade coatings. These ENM's are mainly nanosilver (nano-Ag), nano titanium dioxide (nano-TiO(2)), nano silica (nano-SiO(2)), nano zinc oxide (nano-ZnO), nano alumina (nano-Al(2)O(3)), layered silica (e.g. montmorillonite, Al(2)[(OH)(2)/Si(4)O(10)]nH(2)O), carbon black, and carbon nanotubes (CNT). Knowing full well that innovators have to take decisions today, we have presented some criteria that should be useful in systematically analyzing and interpreting the state of the art on the effects of ENM. For the environment we established the following criteria: (1) the indication for hazardous effects, (2) dissolution in water increases/decreases toxic effects, (3) tendency for agglomeration or sedimentation

  8. Hydraulic permeability of bentonite-polymer composites for application in landfill technology

    Dehn, Hanna; Haase, Hanna; Schanz, Tom


    with Aggressive Inorganic Solutions', Journal of Geotechnical and Geoenvironmental Engineering 140(3). Shackelford, C. D., Benson, C. H., Katsumi, T., Edil, T. B. & Lin, L. (2000), 'Evaluating the hydraulic conductivity of GCLs permeated with non-standard liquids', Geotextiles and Geomembranes 18, 133-161.

  9. Reúso de água em indústria de reciclagem de plástico tipo PEAD Water reuse on HDPE plastics recycling pack industry

    Angela Cristina Orsi Bordonalli


    Full Text Available A discussão acerca da viabilidade técnica, econômica e ambiental do reúso da água em processos industriais tem sido uma preocupação constante. Neste trabalho propõe-se uma alternativa simplificada para o tratamento de efluentes com vistas ao seu reúso em uma indústria de reciclagem de plásticos. A água, no presente caso, é componente fundamental para o processo, já que participa como elemento de remoção de detritos e impurezas que contaminam a matriz da matéria-prima utilizada, proveniente, principalmente, de aterros sanitários e lixões. As embalagens plásticas recicladas pela indústria em questão são, em sua grande maioria, de uso doméstico e, em menor escala, frascos contaminados com óleos lubrificantes. Os resultados demonstraram a viabilidade do tratamento através de processo físico-químico por coagulação, floculação, decantação e filtração em manta geotêxtil, com o uso do hidroxicloreto de alumínio (PAC como coagulante, soda cáustica (50% como alcalinizante e polieletrólito como auxiliar de floculação e desidratação do lodo, bem como a exequibilidade do reúso dos efluentes em circuito fechado.The discussion about technical, economical and environmental feasibility of water reuse in industrial process has been a constant concern. This paper purposes a simplified choice for waste water treatment seeking reuse in a plastic recycle industry. The water, in this case, is a prime component because it is the main element for the debris and impurities removal that contaminates the matrix of plastic raw material, which comes, mostly, from landfill and waste disposals. The recycled plastic packages, from the company that had been used for this research, come mostly from domestic use and, in a minor scale, the plastic package contaminated by lubricant oil. The final results show feasible for the treatment through physical-chemical process by coagulation, flocculation, decantation and filtration on geotextile

  10. 土工合成材料土中拉伸试验研究%Research on In-soil Tensile Test of Geosynthetics

    吴迪; 徐超; 李丹; 祁昌伟


    The soil-reinforcement technology in geosynthetics has become a wildly acceptable approach for constructing soil structure. Homever, the test technique for the geosynthetics is much backward compared with engineering application. For example, there are significant differences between the results of regular tensile test in air and in-soil tensile test for the geosynthetics. In this paper, study on the tensile response test of geosynthetics in-soil using a new developed multifuncational geosynthetics in-soil tensile apparatus under different confinement conditions is done. The in-soil tensile properties of five different geosynthetics under four normal loads are tested. The results show that the differences of test curves between in-air and in-soil tests are big, especially for nonwoven geotextile as reinforce. Because the normal loading on both sides of tensile materials equals a function of side confinement, the secant modulus of geosynthetic incrase significantly.%土工合成材料加筋技术在工程中的应用日益广泛,但其试验手段还显得相对单一,如土工合成材料的拉伸性能往往在空气中进行测试,与实际工程中的土中受力条件有较大差别.本文通过研制的多功能土工合成材料土中拉伸试验机,测试了五种不同土工合成材料的土中拉伸性能及其在四种法向荷载下的表现.结果表明:土工合成材料土中拉伸试验与空气中的差别巨大,尤其对于无纺土工织物.由于两侧土体对拉伸材料施加的法向荷载相当于给予了侧限的作用,拉伸试验中的割线模量具有较大的增大.

  11. Evaluation of oxidative behavior of polyolefin geosynthetics utilizing accelerated aging tests based on temperature and pressure

    Li, Mengjia

    Polyolefin geosynthetics are susceptible to oxidation, which eventually leads to the reduction in their engineering properties. In the application of polyolefin geosynthetics, a major issue is an estimate of the materials durability (i.e. service lifetime) under various aging conditions. Antioxidant packages are added to the polyolefin products to extend the induction time, during which antioxidants are gradually depleted and polymer oxidation reactions are prevented. In this PhD study, an improved laboratory accelerating aging method under elevated and high pressure environments was applied to evaluate the combined effect of temperature and pressure on the depletion of the antioxidants and the oxidation of polymers. Four types of commercial polyolefn geosynthetic materials selected for aging tests included HDPE geogrid, polypropylene woven and nonwoven geotextiles. A total of 33 different temperature/pressure aging conditions were used, with the incubation duration up to 24 months. The applied oven temperature ranged from 35°C to 105°C and the partial oxygen pressure ranged from 0.005 MPa to 6.3 MPa. Using the Oxidative Induction Time (OIT) test, the antioxidant depletion, which is correlated to the decrease of the OIT value, was found to follow apparent first-order decay. The OIT data also showed that, the antioxidant depletion rate increased with temperature according to the Arrhenius equation, while under constant temperatures, the rate increased exponentially with the partial pressure of oxygen. A modified Arrhenius model was developed to fit the antioxidant depletion rate as a function of temperature and pressure and to predict the antioxidant lifetime under various field conditions. This study has developed new temperature/pressure incubation aging test method with lifetime prediction models. Using this new technique, the antioxidant lifetime prediction results are close to regular temperature aging data while the aging duration can be reduced considerably

  12. The impact of olive leaves, mosses and the burrowing of wild boars on soil erosion in olive orchards

    Cerdà, Artemi; Nadal-Romero, Estela; Brevik, Eric C.; Pulido, Manuel; Maestre, Fermando T.; Taguas, Tani; Novara, Agata; Keesstra, Saskia; Cammeraat, Erik; Parras-Alcantara, Luis


    The main factor controlling soil erosion is vegetation cover (Cerdà and Doerr, 2005; Van Eck et al., 2016; van Hall et al., 2017). However, due to the removal of the vegetation in agricultural fields and the increase in soil erosion rates other factors arise as keys to control soil erosion rates and mechanisms (Ochoa-Cueva et al., 2016; Rodrigo Comino et al., 2016). Soil erosion rates in olive plantations are high due to the lack of vegetation cover as a consequence of intensive tillage and herbicides abuse (Taguas et al., 2015; Parras-Alcantara et al., 2016; Zema et al., 2016). This is also found in vineyards and other orchards around the world (Prosdocimi et al., 2016; Rodrígo Comino et al., 2016), and the reason to look for sustainable management techniques such as geotextiles, mulches or catch crops that will stop the accelerated soil erosion (Giménez Morera et al., 2010; Mwango et al., 2016; Nawaz et al., 2016a; 2016b; Nishigaki et al., 2016). All these management techniques are difficult to apply and have high costs. Natural solutions such as weeds to provide cover are very efficient and have no cost (Cerdà et al., 2016; Keesstra et al., 2016) and they can be adapted to the management of the farmers. In olive orchards under herbicide treatment there is a natural growth of mosses and the development of a litter layer composed of olive leaves. There is also burrowing by wild boars that "ploughs" the soil. This research evaluates the impact of the three items above on soil erosion. The measurements were carried out using simulated rainfall experiments over an area of 0.25 m2 at a rainfall rate of 55 mm h-1 during one hour (Cerdà, 1996; Prosdocimi et al., 2017) on 15 plots of mosses, 15 wild boar burrowed surfaces and 15 leaf covered surfaces during the winter of 2015. The soil erosion rates were 34 times greater in the wild boar burrowed soils, meanwhile the litter and mosses covered soils showed similar erosional responses and the soil erosion rates were

  13. Analysis of behavior of polymer screens of high earthfill cofferdamson the basis of the stress-strain state calculations АНАЛИЗ РАБОТЫ ПОЛИМЕРНОГО ЭКРАНА ВЫСОКОЙ ГРУНТОВОЙ ПЕРЕМЫЧКИ НА ОСНОВЕ РАСЧЕТОВ НАПРЯЖЕННО-ДЕФОРМИРОВАННОГО СОСТОЯНИЯ

    Sainov Mikhail Petrovich


    Full Text Available The article deals with the results of the numerical analysis of the stress-strain state of a 50 m high earthfill cofferdam. A geocomposite membrane (geo-membrane and geotextile layers in its upper part (20 m serves as a seepage control element. The grout curtain is installed in the lower part of the cofferdam and in the foundation. The cofferdam design implements the idea of using riprap to reduce the weight of the geocomposite membrane.The analysis proves that the high weight of the membrane considerably worsens the stress state of both the membrane and the whole dam. First of all, the load causes additional deflection of the membrane and consequently increases tensile stresses inside it. Second, due to the low value of the friction coefficient (approximately 0.3 0.4 in the point of contact between the geocomposite membrane and soil the dam upstream shell may slide down along the geocomposite membrane. Additional dam displacements may cause considerable tensile forces in the geomembrane. Their maximum values are comparable to the strength of the polymer material used for the manufacturing of the membrane. Any rupture of the membrane and geotextile layers may be expected. The analysis proves that it is necessary to get compensators in the polymer membrane allowing for the extension of the membrane absent of any tensile forces.The analysis proves that the geocomposite membrane does not affect the stressstrain state of the earth fill due to its small thickness. Non-linear effects of “earth – geomembrane” contacts are to be taken into account, because tensile forces appear inside geo-membranes due to the presence of friction forces.Рассмотрены результаты численного исследования напряженно-деформированного состояния конструкции грунтовой перемычки высотой 50 м, в которой противофильтрационным

  14. 25 Years Of Environmental Remediation In The General Separations Area Of The Savannah River Site: Lessons Learned About What Worked And What Did Not Work In Soil And Groundwater Cleanup

    Blount, Gerald [Savannah River Nuclear Solutions (SRNS), Aiken, SC (United States); Thibault, Jeffrey [Savannah River Nuclear Solutions (SRNS), Aiken, SC (United States); Millings, Margaret [Savannah River Nuclear Solutions (SRNS), Aiken, SC (United States); Prater, Phil [Savannah River Site (SRS), Aiken, SC (United States)


    environmental remediation projects tend to be managed under tri-party agreement (DOE, Environmental Protection Agency, and SCDHEC) through the Federal Facilities Agreement. During 25 years of environmental remediation SRS has stabilized and capped seepage basins, and consolidated and capped waste units and burial grounds in the GSA. Groundwater activities include: pump and treat systems in the groundwater, installation of deep subsurface barrier systems to manage groundwater flow, in situ chemical treatments in the groundwater, and captured contaminated groundwater discharges at the surface for management in a forest irrigation system. Over the last 25 years concentrations of contaminants in the aquifers beneath the GSA and in surface water streams in the GSA have dropped significantly. Closure of 65 waste sites and 4 RCRA facilities has been successfully accomplished. Wastes have been successfully isolated in place beneath a variety of caps and cover systems. Environmental clean-up has progressed to the stage where most of the work involves monitoring, optimization, and maintenance of existing remedial systems. Many lessons have been learned in the process. Geotextile covers outperform low permeability clay caps, especially with respect to the amount of repairs required to upkeep the drainage layers as the caps age. Passive, enhanced natural processes to address groundwater contamination are much more cost effective than pump and treat systems. SRS operated two very large pump and treat systems at the F and H Seepage Basins to attempt to limit the release of tritium to Fourmile Branch, a tributary of the Savannah River. The systems were designed to extract contaminated acidic groundwater, remove all contamination except tritium (not possible to remove the tritium from the water), and inject the tritiated groundwater up-gradient of the source area and the plume. The concept was to increase the travel time of the injected water for radioactive decay of the tritium. The two

  15. Improvement Measures of Stope Filling Dewatering Process in Sanshandao Gold Mine%三山岛金矿采场充填脱水工艺改进措施

    颜丙乾; 杨鹏; 吕文生


    采场充填脱水效果对充填体初凝时间及其短期和长期强度产生较大影响,三山岛金矿采用溢流管溢流脱水和充填挡墙的土工布渗透脱水,脱水效率不能满足现场工作要求。为此,在充填脱水理论研究的基础上,分析了影响充填脱水速度的主要因素,提出了多项充填脱水改进措施。增设竖直或倾斜的脱水管,更有效地排出充填采场中的重力水,同时避免充填料浆中细粒级颗粒堵塞脱水管。改进充填挡墙设计和滤水布的选取,避免细粒级颗粒短时间内聚集在滤水布附近,影响渗透脱水效果。设计充填管道滤水器,在充填料浆进入采空区前,过滤充填料浆中的部分自由水,提高了充填采场中料浆的浓度,减小了采场充填脱水工作量。改变矿山简单脱水方式,进一步提高采场充填脱水效率,避免影响下一步开采工作的顺利开展。%The dewatering of stope filling has a greater impact on the initial setting time of the filling body and its short-term and long-term strength. The overflow dewatering was used in Sanshandao Gold Mine by overflow tube,and penetration de-watering was used by filling retaining geotextile,but the dewatering efficiency can not meet the requirements of field work. The main influence factors of the filling dewatering rate was analyzed on the basis of theoretical research on the filling dewatering, and many improvement measures of filling dewatering are put forward. Additional vertical or inclined dewatering tubes can be used to discharge the filling gravity water more efficiently,meanwhile avoid dewatering tube clogged by the fine-sized particles in filling slurry. The improved design of filling retaining wall and selection of treatment cloth can avoid the fine-sized particles gathered near the water treatment cloth in short time which can affect penetration dewatering. The water filter of filling tube was designed to filter

  16. Penetration and survival of riparian tree roots in compacted coarse gravel mixtures

    Muellner, Michael; Weissteiner, Clemens; Konzel, Christoph; Rauch, Hans Peter


    Root growth and penetration of riparian trees along paved cycling paths and service roads of rivers causes often traffic safety problems. Damages occur mostly on street surfaces with thin asphalt layers and especially in the upper part of the pavement structure. The maintainers of these roads are faced with frequent and high annual repair costs in order to guarantee traffic safety and pleasant cycling conditions. Analyses of the dominating process mechanisms demonstrated that mainly the naturally growing pioneer vegetation along rivers is responsible for the asphalt damages caused by their constant and rapid growth. The investigations of the root growth characteristics showed that tree roots mostly penetrate the road structure between the gravel sublayer and the asphalt because of the high compaction of the layer itself. In a second step of the research project the influence of different gravel size mixtures on the root penetration and survival are analysed. Coarse gravel size mixtures with the lowest possible fine granular fraction are suposed to inhibit root growth due to the mechanical impedance and air pruning of roots. Furthermore coarse gravel size mixtures could influence the presence of condensate formed at the underside of the asphalt layer. Therefore seven different compositions of matrix stone gravel size mixtures (0/32, 4/32, 8/32, 16/32, 0/64, 8/64 hydraulic bound mixture and 16/64) as sublayer material were tested in a small scale experimental set-up. Wooden boxes with a dimension of 1x1.5x0.5 m and 0.5x0.5x0.5 m were used as frames for the different matrix stone mixtures. On one side the boxes were delimited to the surrounding soil with a steel mesh followed by a wire mesh and a geotextile. Boxes were located in an 80 cm deep hole on a 30 cm thick drainage layer. Willow and poplar cuttings were planted laterally to the root penetrable side of the boxes. Large boxes were filled and compacted with 6 different gravel size mixtures (all but 4/32) and

  17. Engineering protection of pipelinesfrom erosion processes Инженерная защита трубопроводов от эрозионных процессов

    Skapintsev Aleksandr Evgen’evich


    Full Text Available The authors consider varied engineering actions aimed at the protection of pipelines from developing erosion processes with a focus on the conditions of northern regions. Engineering solutions, considered in the article, include prevention of erosion processes along pipelines, protection from suffusion, protection of extended areas having the limit value of the slope angle, and actions aimed at the drainage of areas along pipelines. Prevention of erosion processes along pipelines consists in the restoration of the fertile layer using biological methods, as well as the volumetric soil reinforcement using geological grids. Prevention of suffusion processes consists in the employment of various types of suffusion shields accompanied by the application of geotextile. Berms are constructed as suffusion prevention actions in extended areas having a limit value of the slope angle. This action is used to reduce the water flow energy of drainage ditches and trays along the pipeline. The authors believe that a complete geotechnical monitoring network must be designed and developed to monitor the condition of pipelines and foundation soils.Рассмотрены различные варианты мероприятий инженерной защиты трубопроводов от активизирующихся и развивающихся эрозионных процессов преимущественно в условиях северных регионов. Рассмотрены технические решения на участках вдольтрассовой эрозии, участках развития суффозионных процессов, технические решения на протяженных участках с предельной величиной угла наклона естественной поверхности, а также мероприятия инженерной защиты по осу

  18. Monitoramento em longo prazo da contenção vegetativa em talude rodoviário de saprolito de gnaisse em Minas Gerais Long-term monitoring of vegetative stabilization of a road slope of gnaisse saprolite in Minas Gerais

    Rosilene Einloft


    with vegetative stabilization and, in the long term, the appearance of new cover forms or soil exposure in response to planting grasses and legumes on a steep road slope alongside a highway. After four years of recovery, new forms of soil cover or exposure were observed in the experimental plots, called typologies, described below: brachiaria grass cover, legume plants, gordura grass, invasive species, geotextile, decomposing residues, microphytic crusts, soil crust, exposed soil, erosion, and rock outcrops. The characteristics of these typologies were quantified by two surveys, before and after the rainy season. In addition, the different typologies of each experimental plot were mapped; these maps were used to analyze the dynamics, spatial distribution, frequency, and competition among typologies identified in the two surveys. Of the total 11 typologies, the vegetation species and microphytic crusts were the most relevant for revegetation. Microphytic crusts were very important in the initial stage of ecological succession, resulting in rapid stabilization and reclamation of degraded surfaces and favoring the appearance of invasive species. The seasonal variation between the two surveys showed that erosion and soil exposure decreased with increase in vegetation cover and microphytic crust development.

  19. Is timing of prescribed fire critical for limiting post-fire erosion? Lessons from Portugal

    Shakesby, Richard A.; Ferreira, Carla S. S.; Walsh, Rory P. D.; Ferreira, António J. D.; Urbanek, Emilia; Stoof, Cathelijne R.


    The rapid increase in fire activity in parts of the Mediterranean from the 1960s onwards led to a rise in interest in the application of prescribed fire as a method of reducing fuel loads and thereby limiting the likelihood of the occurrence of severe wildfires and the size of the areas affected. The ‘windows of opportunity' for carrying out controlled burning are restricted to comparatively brief periods during the autumn through to late spring when wind direction and strength, air temperature and humidity, and fuel load moisture contents are judged to be appropriate. Given that the most erosive rainfall events are often in the autumn to early winter, delaying prescribed fire until later in the winter might be seen as having advantages in reducing post-fire erosional losses of ash, sediment and nutrients, particularly in wetter regions, as on the Atlantic fringe of the Mediterranean. Burning in late winter or spring might be expected to limit the chances of early post-fire heavy and erosive rainfall events. This would allow good vegetation recovery throughout spring and summer before the intense rainfall events likely to occur from the autumn onwards. As part of the EU-funded DESIRE project investigating ways of mitigating the detrimental effects of wildfire on land degradation, a small (9 ha), steep catchment comprising mainly scrub vegetation with encroaching pines in central Portugal was subjected to experimental fire. Although scheduled for autumn-early winter, delay of burning until February 20th 2009 proved necessary because of persistent rainfall and ground conditions too wet for burning. Sediment losses were monitored before and after the burn at the hillslope scale using a series of sediment fences. These comprise geotextile material supported against a frame made of steel bars forming a trap for sediment eroded from upslope. Knowing the contributing areas for eroded material reaching the fences enables erosion rates to be determined. Early results

  20. Spatial-temporal variability of the microbial respiration at the regional scale: comparison of field and laboratory approaches

    Vasenev, Viacheslav; Stoorvogel, Jetse; Ananyeva, Nadezhda D.; Valentini, Riccardo


    Regional carbon assessments are increasingly important. Soil respiration is a predominant carbon efflux of terrestrial ecosystems. The total carbon efflux from soils includes autotrophic respiration of root systems and heterotrophic microbial respiration (MR). MR usually refers to 60-80% of the total efflux and thus plays a key role in regional carbon balance. Quite a few studies report high sensitivity of MR to climate conditions and land-use. Different approaches to analyze MR exist. The methods differ in the procedures to consider space and time variability. We evaluated two approaches to assess MR variability. One approach uses field measurements on a limited number of locations with chambers. The other approach samples more intensively and derives basal respiration (BR) from measurements under standard conditions in the laboratory. The chamber approach includes periodic measurements at a limited number of sites. As such, the methodology provides appropriate information on temporal dynamics. Spatial variability although, is underrepresented .. In our case chambers were mounted in forest, cropland and urban sites (n=48) located in the north of Moscow city. Roots were removed and geotextile (1 micron mesh) bags were inserted in soil to segregate MR. The flux was measured weekly by Li-6400-XT from July till September 2012. In contrast, standardized BR techniques minimize the diversity of initial conditions. This allows to increase the number of observations considerably. However, the temporal variance is avoided. BR was analyzed in mixed topsoil (0-10 cm) and subsoil (10-150 cm) samples (n=182) collected in forest, cropland and urban sites from different bioclimatic zones of Moscow region. After preincubation (T=22°C, 55% water content, 7 days) soil MR (in μg ?O2-? g-1) was measured after incubating 2g soil with 0.2 μl distilled water as the rate of ?O2 production (22° ?, 24 h) by gas chromatography. Both approaches can be used to describe MR variability in

  1. Bioengineering applied to erosion and stability control in the North Apennines (Emilia-Romagna Region, Italy): a check about critical aspects of the works.

    Selli, Lavinia; Cavazza, Claudio; Pavanelli, Donatella


    Because of its geological structure, in the Emilia-Romagna Region over 32,000 landslides have been identified. Several works have been made in order to control mass movement's dynamics and to secure of Reno and Lamone Mountain Basin Rivers, the road network and near by villages and towns. Most of the control works dealt with bioengineering practices: palisades piles, geotextiles, seedings, surface flow control works, dikes within main drainage ditches. In order to check about critical aspects related to the use of these techniques in the Apennines, a survey in this basins was designed with specific interest in the several kinds of works realised, in which plant species were mostly used and in the factors that affected the success or failure of the works. Territory encompasses steep slopes covered with woods to low reliefs covered with grasslands. It is characterized by prevailing clays, inducing instability, and arenaceous lithology with impermeable soils; drainage density is quite high and hillsides suffer extensive and severe erosion and slope stability problems. Chestnut woods mainly represent land use at higher altitudes, while coppice, pastures and crops are present on milder hillsides. The remaining part of the basin is covered by vineyards, orchards, ponds and urban areas, which are basically located in the valley floor. Precipitation events mainly consist of rainfall ranging between 950-1015 mm per year; few snowfalls occur during winter and a long dry season lasts from June until September. We have analyzed 187 works designed mainly for the consolidation of slope instabilities through a widespread enhancement of the vegetation cover. The surveyed works are classified as a function of their building features: it can be seen that cribwalls and palisades are by far the most common types, being the 24% and the 34% respectively of the works. As far as the most adopted plant species, they were silver willow (Salix alba), Spanish Broom (Spartium Junceum) and

  2. How effective are soil and water conservation techniques in reducing annual plot runoff and soil loss? A pan-European and Mediterranean review and analysis.

    Maetens, W.; Poesen, J.; Vanmaercke, M.


    While a substantial number of experimental studies on the effectiveness of soil and water conservation techniques (SWCTs) in reducing annual runoff (Ra) and annual soil loss (SLa) at plot scales in Europe and the Mediterranean exists, a comprehensive overview and analysis of plot Ra and SLa data is lacking. Therefore, the objective of this study is to analyse the effectiveness of SWCT in reducing Ra and SLa in Europe and the Mediterranean, as well as to explore the factors that determine SWCT effectiveness. In the framework of the FP6 project DESIRE (, a comprehensive plot database was compiled based on an extensive literature review covering 101 reports and publications. The database contains Ra and SLa data measured on runoff plots, where various SWCTs were tested in the Euro-Mediterranean region. The total database contains 353 plots, corresponding to 2 093 plot-years from 103 plot measuring stations throughout Europe and the Mediterranean. For 224 of these plots (corresponding to 1 567 plot-years), Ra and/or SLa from a paired plot with the same dimensions, land use and measuring period, but without the application SWCT was available, allowing to assess the effectiveness of the applied SWCTs. Documented SWCTs include cover crops, mulching, grass buffer strips, strip cropping, exclosure, no-tillage, reduced tillage, contour tillage, deep tillage, drainage, soil amendment, terraces, contour bunds and geotextiles. Analyses of the database shows that there are clear differences in effectiveness in reducing Ra and SLa between different SWCTs. Techniques related to crop and vegetation management like mulching (median reduction of Ra to 32% and SLa to 23% of the corresponding values measured on the plot without SWCT) and cover crops (36% for Ra and 14% for SLa) are more effective than soil management techniques like no-tillage (85% for Ra and 57% for SLa) or reduced tillage (90% for Ra and 68% for SLa). While these techniques are commonly

  3. Plant Biodiversity of the Damaged River Bank and Their Relationship with Soil Properties at the Beginning of Restoration in Taohua River of Chongqing City%重庆市桃花溪受损河岸植被恢复初期物种多样性变化及其对土壤环境效应的影响

    孟凡超; 王玉杰; 赵占军; 赵洋毅; 雷声坤


    Because of artificial interference,the plant of river bank in Taohua has been damaged.After eco-restoration of the river bank,plant recovered rather well.Based on the survey on community in the plots,we studied the plant species diversity,soil properties and their relationship at the beginning of restoration with one way ANOVA analysis,correlation analysis and multiple regression methods.Twelve soil indicators were selected to describe soil physical properties and nutrient characteristics,including soil bulk density,capillary pore,non-capillary pore,active acid(pH),organic matter,total N,total P,total K,available N,available P,available K and soil cation exchange capacity(CEC).The results showed that the species diversity of the plant slope protection and natural materials fabric pad which is little better than geotextile flat bag was the highest.The species diversity has been greatly improved compared with bared river bank.In all of the river bank models,the difference of the most soil chemical and physical characters,which of the bared river bank have the best soil fertility condition,is extremely obvious.Through correlation analysis and multiple regression methods between invasive plants on soil biodiversity and soil chemical and physical characters,the indices of invasive plants on soil biodiversity are negative correlation to soil bulk density.In all of indices,Margalef index and Simpson index are obvious positive relation to capillary pore,available N and CEC as well as extremely obvious positive relation to organic matter.Shannon-Wiener index and Pielou index are extremely obvious positive relation to capillary pore as well as obvious positive relation to organic matter.In all soil chemical and physical characters,total K,organic matter,CEC had the closest relationship with species diversity.%重庆市长寿区桃花溪由于人为干扰部分河岸受损,河岸植被破坏严重,经过生态治理修复,植被恢复效果良好。通过野外实地

  4. 25 Years Of Environmental Remediation In The General Separations Area Of The Savannah River Site: Lessons Learned About What Worked And What Did Not Work In Soil And Groundwater Cleanup

    Blount, Gerald [Savannah River Nuclear Solutions (SRNS), Aiken, SC (United States); Thibault, Jeffrey [Savannah River Nuclear Solutions (SRNS), Aiken, SC (United States); Millings, Margaret [Savannah River Nuclear Solutions (SRNS), Aiken, SC (United States); Prater, Phil [Savannah River Site (SRS), Aiken, SC (United States)


    environmental remediation projects tend to be managed under tri-party agreement (DOE, Environmental Protection Agency, and SCDHEC) through the Federal Facilities Agreement. During 25 years of environmental remediation SRS has stabilized and capped seepage basins, and consolidated and capped waste units and burial grounds in the GSA. Groundwater activities include: pump and treat systems in the groundwater, installation of deep subsurface barrier systems to manage groundwater flow, in situ chemical treatments in the groundwater, and captured contaminated groundwater discharges at the surface for management in a forest irrigation system. Over the last 25 years concentrations of contaminants in the aquifers beneath the GSA and in surface water streams in the GSA have dropped significantly. Closure of 65 waste sites and 4 RCRA facilities has been successfully accomplished. Wastes have been successfully isolated in place beneath a variety of caps and cover systems. Environmental clean-up has progressed to the stage where most of the work involves monitoring, optimization, and maintenance of existing remedial systems. Many lessons have been learned in the process. Geotextile covers outperform low permeability clay caps, especially with respect to the amount of repairs required to upkeep the drainage layers as the caps age. Passive, enhanced natural processes to address groundwater contamination are much more cost effective than pump and treat systems. SRS operated two very large pump and treat systems at the F and H Seepage Basins to attempt to limit the release of tritium to Fourmile Branch, a tributary of the Savannah River. The systems were designed to extract contaminated acidic groundwater, remove all contamination except tritium (not possible to remove the tritium from the water), and inject the tritiated groundwater up-gradient of the source area and the plume. The concept was to increase the travel time of the injected water for radioactive decay of the tritium. The two

  5. Engineered Barrier Testing at the INEEL Engineered Barriers Test Facility: FY-1997 and FY-1999

    Keck, K. N.; Porro, I.


    Engineered barriers of two designs are being tested at the Engineered Barriers Test Facility (EBTF) at the Idaho National Engineering and Environmental Laboratory. This report describes the test facility, barrier designs, and instruments used to monitor the test plots. Wetting tests conducted on the test plots in FY-97 are described and data collected from monitoring the test plots before, during and after the wetting tests are used to evaluate the performance of the covers during FY-97 and FY-98. Replicates of two engineered barrier designs were constructed in the EBTF cells. The first design comprises a thick, vegetated soil cover. The second design incorporates a capillary/biobarrier within the vegtated soil cover. The capillary barrier uses the textural break between an upper, fine textured soil and a lower, coarser-textured gravel layer to inhibit drainage under unsaturated conditions while increasing soil moisture storage in the root zone. Evaporation and transpiration by plants (although the test plots have not yet been vegetated) are used to recycle water stored in the soil back to the atmosphere. A geotextile fabric is used to maintain separation of the soil and gravel layers. A thick layer of cobbles beneath the gravel layer serves as a biobarrier to prevent intrusion of plant roots and burrowing animals into underlying waste (there is no waste in the test plots). Each test plot was instrumented with time domain reflectometry probes and neutron probe access tubes to measure moisture contents, tensiometers, heat dissipation sensors, and thermocouple psychrometers to measure matric potentials, thermocouples to measure soil temperature, and ion-exchange resin beads to monitor tracer movement. Each drainage sump is equipped with a tipping bucket instrument and pressure transducer to measure drainage. Precipitation is measured using a heated rain gauge located at the EBTF. Instrument calibration equation coefficients are presented, and data reduction

  6. Modeling the effect of flow homogeneity on the fate of Cd, Pb and Zn in a calcareous soil

    Lassabatere, Laurent; Spadini, Lorenzo; Delolme, Cécile; Galvez, Rosa; Winiarski, Thierry


    predict Cd, Pb and Zn elution and retention for several scenarios regarding flow homogeneity. The numerical sensitivity analysis quantifies the effect of the fraction of mobile water and the solute exchange rate between mobile and immobile water fractions. The modeling clearly shows that the degree of flow homogeneity should impact both heavy metal modeled elution and retention in the soil profile. However, the impacts depend on both the hydrodynamics of flow (mobile water fraction and solute exchange rate between mobile and immobile fractions) and the type of geochemical mechanism involved in heavy metal retention and elution (cationic exchange, versus precipitation). Lassabatere L, Spadini L, Delolme C, et al (2007) Concomitant Zn-Cd and Pb retention in a carbonated fluvio-glacial deposit under both static and dynamic conditions. Chemosphere 69:1499-1508. Lassabatere L, Winiarski T, Galvez Cloutier R (2004) Retention of three heavy metals (Zn, Pb, and Cd) in a calcareous soil controlled by the modification of flow with geotextiles. Environ Sci Technol 38:4215-4221.

  7. Assessing different agricultural managements with the use of soil quality indices in a Mediteranean calcareous soil

    Morugán-Coronado, Alicia; García-Orenes, Fuensanta; Mataix-Solera, Jorge; Arcenegui, Vicky; Cerdà, Artemi


    Soil erosion is a major problem in the Mediterranean region due to the arid conditions and torrential rainfalls, which contribute to the degradation of agricultural land. New strategies must be developed to reduce soil losses and recover or maintain soil functionality in order to achieve a sustainable agriculture. An experiment was designed to evaluate the effect of different agricultural management on soil properties and soil quality. Ten different treatments (contact herbicide, systemic herbicide, ploughing, Oat mulch non-plough, Oats mulch plough, leguminous plant, straw rice mulch, chipped pruned branches, residual-herbicide and agro geo-textile, and three control plots including no tillage or control and long agricultural abandonment (shrub on marls and shrub on limestone) were established in 'El Teularet experimental station' located in the Sierra de Enguera (Valencia, Spain). The soil is a Typic Xerorthent developed over Cretaceous marls in an old agricultural terrace. The agricultural management can modify the soil equilibrium and affect its quality. In this work two soil quality indices (models) developed by Zornoza et al. (2007) are used to evaluate the effects of the different agricultural management along 4 years. The models were developed studying different soil properties in undisturbed forest soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. Model 1, that explained 92% of the variance in soil organic carbon (SOC) showed that the SOC can be calculated by the linear combination of 6 physical, chemical and biochemical properties (acid phosphatase, water holding capacity (WHC), electrical conductivity (EC), available phosphorus (P), cation exchange capacity (CEC) and aggregate stability (AS). Model 2 explains 89% of the SOC variance, which can be calculated by means of 7 chemical and biochemical properties (urease, phosphatase, and ß-glucosidase activities, pH, EC, P and CEC). We use the

  8. Saint Joseph's University Institute for Environmental Stewardship

    McCann, Micahel P.; Springer, Clint J.


    future climate scenarios is local adaptation and not necessarily genome size as has been hypothesized in the literature. Task B: Installation of an extensive green roof system on the Science Center at Saint Joseph's University for research, research-training and educational outreach activities. An experimental green roof system was designed and installed by an outside contractor (Roofmeadows) on the roof of the Science Center at Saint Joseph's University. The roof system includes four test plots, each with a different drainage system, instrumentation to monitor storm water retention, roof deck temperature, heat flux into and out of the building, rain fall, wind speed and direction, relative humidity and heat emission from the roof system. The vegetative roof was planted with 26 species of plants, distributed throughout the roof area, to assess species/variety growth and coverage characteristics, both in terms of the different drain layer systems, and in terms of the different exposures along the north to south axis of the building. Analysis of the drain layer performance, in terms of storm water retention, shows that the aggregate (stone) drainage layer system performed the best, with the moisture management mat system second, and the geotextile drain layer and reservoir sheet layer systems coming in last. This information is of value in the planning and design of vegetative roof systems since the different types of drainage layer systems have different installation costs and different weights. The different drainage layer systems also seem to be having an impact on plant growth and spread with the test plot with the reservoir sheet layer actually having the poorest plant coverage and plant spread of all areas of the roof studied. Plant growth performance analysis is ongoing, but significant differences have been observed in the third growing season ('13) along the north to south axis, with most species doing better towards the northern end of the roof (in

  9. The contribution of mulches to control high soil erosion rates in vineyards in Eastern Spain

    Cerdà, Artemi; Jordán, Antonio; Zavala, Lorena; José Marqués, María; Novara, Agata


    Soil erosion take place in degraded ecosystem where the lack of vegetation, drought, erodible parent material and deforestation take place (Borelli et al., 2013; Haregeweyn et al., 2013; Zhao et al., 2013). Agriculture management developed new landscapes (Ore and Bruins, 2012) and use to trigger non-sustainable soil erosion rates (Zema et al., 2012). High erosion rates were measured in agriculture land (Cerdà et al., 2009), but it is also possible to develop managements that will control the soil and water losses, such as organic amendments (Marqués et al., 2005), plant cover (Marqués et al., 2007) and geotextiles (Giménez Morera et al., 2010). The most successful management to restore the structural stability and the biological activity of the agriculture soil has been the organic mulches (García Orenes et al; 2009; 2010; 2012). The straw mulch is also very successful on bare fire affected soil (Robichaud et al., 2013a; 2013b), which also contributes to a more stable soil moisture content (García-Moreno et al., 2013). The objective of this research is to determine the impact of two mulches: wheat straw and chipped branches, on the soil erosion rates in a rainfed vineyard in Eastern Spain. The research site is located in the Les Alcusses Valley within the Moixent municipality. The Mean annual temperature is 13 ºC, and the mean annual rainfall 455 mm. Soil are sandy loam, and are developed at the foot-slope of a Cretaceous limestone range, the Serra Grossa range. The soils use to be ploughed and the features of soil erosion are found after each thunderstorm. Rills are removed by ploughing. Thirty rainfall simulation experiments were carried out in summer 2011 during the summer drought period. The simulated rainfall lasted during 1 hour at a 45 mmh-1 intensity on 1 m2 plots (Cerdà and Doerr, 2010; Cerdà and Jurgensen 2011). Ten experiments were carried out on the control plots (ploughed), 10 on straw mulch covered plots, and 10 on chipped branches covered

  10. The positive impact of European subsidies on soil erosion rates in orange plantations

    Keesstra, Saskia; Jordán, Antonio; Novara, Agata; Taguas, Tani; Pereira, Paulo; Brevik, Eric C.; Cerdà, Artemi


    Soil erosion in orchards and vineyards has been found non-sustainable due to bare soils due to the use of herbicides and tillage (Novara et al., 2011; Taguas et al., 2015; Ochoa et al., 2016; Rodrigo Comino et al., 2016a; 2016b; 2016c). Citrus plantations in sloping terrains are also non-sustainable from the soil erosion point of view due high erosion rates and the damage caused on infra-structures (Cerdà et al., 2009; 2009b; Cerdà et al., 2011; Pereira et al., 2015). This is not uncommon in Mediterranean type Ecosystems (Cerdà et al., 2010) but there is a need to reduce the soil and water losses to achieve sustainability (Brevik et al., 2015; Keesstra et al., 2016). The use of mulches, geotextiles, catch crops, and vegetation was found to be very successful as a sustainable strategy to reduce the soil losses (Giménez Morera et al., 2010; Mwango et al., 2016; Nawaz et al., 2016; Nishigaki et al., 2016; Prosdocimi et al., 2016). Nowadays, chipped branches are applied in orchards and vineyards because of European subsidies; however little scientific data is available on the impact of the chipped branches mulch on soil erosion. In an orange plantation in Eastern Valencia, at the L'Alcoleja experimental station the impact of these chipped branches was tested under 45 mm h-1 rainfall simulations on laboratory plots of 0.5 m2 under with different covers of chipped branches. The results show that with a cover of 20 % with chipped branches soil erosion reduces by 78 %. Acknowledgements The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement 603498 (RECARE project) and the CGL2013- 47862-C2-1-R and CGL2016-75178-C2-2-R national research projects. References Brevik, E. C., Cerdà, A., Mataix-Solera, J., Pereg, L., Quinton, J. N., Six, J., and Van Oost, K. 2015. The interdisciplinary nature of SOIL, SOIL, 1, 117-129, doi:10.5194/soil-1-117-2015, Cerdà, A. and M. F. Jurgensen

  11. Diffusion, sorption, and retardation processes of anions in bentonite and organo-bentonites for multibarrier systems

    Schampera, Birgit; Dultz, Stefan


    experiments with NO3- will support the understanding of sorption behavior of the anions. All hydrophilic samples have a higher retardation capacity, indicated by diffusion coefficients of 2.44 x 10-11 m/s2 for original bentonite and ˜2.1 x 10-11m/s2 for hydrophilic organo-clays. For hydrophobic organo-clays the H2O diffusion can be higher and is increased at high bulk density (1-1.5 g/m3) up to 2.76 x 10-10m2/s. Experiments with NO3- at bulk density of 1.5 g/m3 reveal that the apparent diffusion coefficients of nitrate are with results up to 5.61 x 1012 m2/s distinctively lower than free diffusion of nitrate in pure water (6.46 x 1010 m2/s at experimental conditions) and nitrate diffusion in natural bentonite (2.63 x 1011 m2/s). The measurements allow the interpretation of the different sorption mechanisms, retardation capacity and diffusion behavior of the analyzed clays at different anion concentrations. Ongoing molecular dynamic simulations will contribute understanding of diffusion processes in organo-clays including the conditions at the interface of the clay minerals and in solution. References: [1] Shackelford, C.D., Moore S.M. (2013) Fickian diffusion of radionuclides for engineered containment barriers: Diffusion coefficients, porosities, and complicating issues. Engineering Geology, 152, 133-147. [2] Rytwo, G., Nir, S., Shuali, U. (2012) Clay and water treatment. Applied Clay Science, 67-68, 117-118. [3] Lorenzetti, R.L., Bartelt-Hunt, S.L., Burns, S.E., Smith, J.A. (2005) Hydraulic conductivities and effective diffusion coefficients of geosynthetic clay liners with organobentonite amendments. Geotextiles and Geomembranes, 23, 385-400. [4] Schampera, B., Dultz, S. (2011) H2O self-diffusion in compacted clays as influenced by surface charge and wettability - obstruction effects of bound H2O layers. Clay and Clay Minerals,59, 42-57.

  12. Saint Joseph's University Institute for Environmental Stewardship

    McCann, Micahel P. [Saint Joseph' s Univ., Philadelphia, PA (United States); Springer, Clint J. [Saint Joseph' s Univ., Philadelphia, PA (United States)


    future climate scenarios is local adaptation and not necessarily genome size as has been hypothesized in the literature. Task B: Installation of an extensive green roof system on the Science Center at Saint Joseph's University for research, research-training and educational outreach activities. An experimental green roof system was designed and installed by an outside contractor (Roofmeadows) on the roof of the Science Center at Saint Joseph's University. The roof system includes four test plots, each with a different drainage system, instrumentation to monitor storm water retention, roof deck temperature, heat flux into and out of the building, rain fall, wind speed and direction, relative humidity and heat emission from the roof system. The vegetative roof was planted with 26 species of plants, distributed throughout the roof area, to assess species/variety growth and coverage characteristics, both in terms of the different drain layer systems, and in terms of the different exposures along the north to south axis of the building. Analysis of the drain layer performance, in terms of storm water retention, shows that the aggregate (stone) drainage layer system performed the best, with the moisture management mat system second, and the geotextile drain layer and reservoir sheet layer systems coming in last. This information is of value in the planning and design of vegetative roof systems since the different types of drainage layer systems have different installation costs and different weights. The different drainage layer systems also seem to be having an impact on plant growth and spread with the test plot with the reservoir sheet layer actually having the poorest plant coverage and plant spread of all areas of the roof studied. Plant growth performance analysis is ongoing, but significant differences have been observed in the third growing season ('13) along the north to south axis, with most species doing better towards the northern end of the roof (in


    翁效林; 马豪豪; 梁东平


    Aiming to study the loess area highway widening project,based on the large-scale foundation settlement simulation test platform,a scale test with the geometry similarity ratio of 1∶1 is carried out;and the roadbed internal soil and the reinforcing material deformation monitoring systems is also established to analyze the response mechanism of internal soil and reinforcement of the roadbed constructed under the conditions of old and new foundation differential settlements. The results show that:under the widened embankment load,the roadbed internal soil experiences a constant process of deformation and coordination with the increasing foundation differential settlement. When the differential settlement S reaches to 9 cm,subgrade and pavement layer appear a slight void. Laying the geotextile material on old and new roadbed splicing segment can lead loose soil to form the compaction complex,which can enhance the overall stability and mechanical properties of roadbed soil and easily form the arch effect. Besides,the geogrid can digest the settlement between new and old roadbed in a certain degree,but the effect is limited. The geogrid inside the soil plays a coordination role in the subgrade soil deformation. The reinforcement force is not uniform and the corresponding alternating of tension and compression strain appears. With the increasing foundation differential settlement,strain show a increasing trend as a whole. When the differential settlement S between old and new foundation reaches to 16 cm,tension and compression strain of geogrid tend to be stable. The ultimate amount of geogrid tensile or compression changes only 2 mm,far less than the destruction limit of geogrid.%以黄土地区高速公路拓宽工程为研究背景,借助大型地基沉降模拟试验平台,实现拓宽路基荷载下地基沉降变形的人为模拟,开展几何相似比为1∶1的足尺模型试验,建立路基内部土体及加筋材料变形监测系统,分析新老

  14. Saint Joseph's University Institute for Environmental Stewardship

    McCann, Michael; Springer, Clint


    future climate scenarios is local adaptation and not necessarily genome size as has been hypothesized in the literature. Task B: Installation of an extensive green roof system on the Science Center at Saint Joseph's University for research, research-training and educational outreach activities. An experimental green roof system was designed and installed by an outside contractor (Roofmeadows) on the roof of the Science Center at Saint Joseph's University. The roof system includes four test plots, each with a different drainage system, instrumentation to monitor storm water retention, roof deck temperature, heat flux into and out of the building, rain fall, wind speed and direction, relative humidity and heat emission from the roof system. The vegetative roof was planted with 26 species of plants, distributed throughout the roof area, to assess species/variety growth and coverage characteristics, both in terms of the different drain layer systems, and in terms of the different exposures along the north to south axis of the building. Analysis of the drain layer performance, in terms of storm water retention, shows that the aggregate (stone) drainage layer system performed the best, with the moisture management mat system second, and the geotextile drain layer and reservoir sheet layer systems coming in last. This information is of value in the planning and design of vegetative roof systems since the different types of drainage layer systems have different installation costs and different weights. The different drainage layer systems also seem to be having an impact on plant growth and spread with the test plot with the reservoir sheet layer actually having the poorest plant coverage and plant spread of all areas of the roof studied. Plant growth performance analysis is ongoing, but significant differences have been observed in the third growing season ('13) along the north to south axis, with most species doing better towards the northern end of the roof (in

  15. Saint Joseph's University Institute for Environmental Stewardship

    McCann, Michael P.; Springer, Clint J.


    future climate scenarios is local adaptation and not necessarily genome size as has been hypothesized in the literature. Task B: Installation of an extensive green roof system on the Science Center at Saint Joseph's University for research, research-training and educational outreach activities. An experimental green roof system was designed and installed by an outside contractor (Roofmeadows) on the roof of the Science Center at Saint Joseph's University. The roof system includes four test plots, each with a different drainage system, instrumentation to monitor storm water retention, roof deck temperature, heat flux into and out of the building, rain fall, wind speed and direction, relative humidity and heat emission from the roof system. The vegetative roof was planted with 26 species of plants, distributed throughout the roof area, to assess species/variety growth and coverage characteristics, both in terms of the different drain layer systems, and in terms of the different exposures along the north to south axis of the building. Analysis of the drain layer performance, in terms of storm water retention, shows that the aggregate (stone) drainage layer system performed the best, with the moisture management mat system second, and the geotextile drain layer and reservoir sheet layer systems coming in last. This information is of value in the planning and design of vegetative roof systems since the different types of drainage layer systems have different installation costs and different weights. The different drainage layer systems also seem to be having an impact on plant growth and spread with the test plot with the reservoir sheet layer actually having the poorest plant coverage and plant spread of all areas of the roof studied. Plant growth performance analysis is ongoing, but significant differences have been observed in the third growing season ('13) along the north to south axis, with most species doing better towards the northern end of the roof (in

  16. Saint Joseph's University Institute for Environmental Stewardship

    McCann, Michael P; Springer, Clint


    Center at Saint Joseph's University. The roof system includes four test plots, each with a different drainage system, instrumentation to monitor storm water retention, roof deck temperature, heat flux into and out of the building, rain fall, wind speed and direction, relative humidity and heat emission from the roof system. The vegetative roof was planted with 26 species of plants, distributed throughout the roof area, to assess species/variety growth and coverage characteristics, both in terms of the different drain layer systems, and in terms of the different exposures along the north to south axis of the building. Analysis of the drain layer performance, in terms of storm water retention, shows that the aggregate (stone) drainage layer system performed the best, with the moisture management mat system second, and the geotextile drain layer and reservoir sheet layer systems coming in last. Plant growth performance analysis is ongoing, but significant differences have been observed in the third growing season ('13) along the north to south axis, with most species doing better towards the northern end of the roof (in terms of percent ground coverage and plant spread and reproduction). Interestingly, plant growth in all four of the test plots was reduced relative to the lower areas of the roof (the lower area was ca. 2 inches lower than the test plots, due to the space needed for sensors under the plots. The lower roof area uses an aggregate drain layer comparable to that in the third test plot), even when accounting for the north to south differences. The reasons for these differences are not clear and studies are underway to examine the impact of wind scour, drainage rates, temperature, and other factors. Task C: Education and community outreach efforts by the IES involving conferences at SJU, presentations by faculty and students off campus, and educational signage. The Institute for Environmental Stewardship hosted three storm water management workshops on

  17. Environmental Sensitive Areas (ESAs) changes in the Canyoles river watershed in Eastern Spain since the European Common Agriculture Policies (CAP) implementation

    Ángel González Peñaloza, Félix; Cerdà, Artemi


    increase in the rangeland vegetation that is dominated by scrubland, meanwhile the woodlands are reduced. Circa 50 % of the land that was classified as "Critical" to land degradation after 1985 had been previously classified as "Non-affected". However, not all changes occurred in the Cànyoles watershed are characterized by a negative change; i.e., 82 % of the land has turned from "Critical" values to "Non- sensitive" to land degradation between mid-20th century and recent times. We found this negative trend to be having been caused by the removal of those crops that are most sensitive to land degradation, such as rain-fed crops, and that are mainly located in the west of the studied watershed. Similar findings were found by Zema et al., (2012) when applying the AnnAGNPS model to the agriculture land in Belgiums, Prokop and Poreba (2012) to the India, Miao e t al., (2012) in China and Haile and Fetene (2012) in Ethiopia: man made changes in the landscape that trigger land degradation processes.. Acknowledgements This research was undertaken in the frame of the 7FP project LEDDRA - Land Ecosystem Degradation and Desertification: Assessing the Fit of Responses - ENV, 2009. We thank professor Costas Kosmas for his guidance. References Cerdà, A., Doerr, S.H. 2007. Soil wettability, runoff and erodibility of major dry-Mediterranean land use types on calcareous soils. Hydrological Processes, 21, 2325-2336. doi: 10.1016/j.catena.2008.03.010. Cerdà, A., Giménez-Morera, A. y Bodí, M.B. 2009. Soil and water losses from new citrus orchards growing on sloped soils in the western Mediterranean basin. Earth Surface Processes and Landforms, 34, 1822-1830. DOI: 10.1002/esp.1889 Cerdà, A., Lasanta, A. 2005. Long-term erosional responses after fire in the Central Spanish Pyrenees: 1. Water and sediment yield. Catena, 60, 59-80. Giménez Morera, A., Ruiz Sinoga, J.D. y Cerdà, A. 2010. The impact of cotton geotextiles on soil and water losses in Mediterranean rainfed

  18. The use of chipped pruned branches to control the soil and water losses in citrus plantations in Eastern Spain

    Cerdà, Artemi; Keesstra, Saskia; Jordán, Antonio; Pereira, Paulo; Prosdocimi, Massimo; Ritsema, Coen J.; Burguet, María


    Soil erosion is the main cause of soil degradation in agriculture land, which is a world-wide problem (Cerdà et al., 2009; Novara et al., 2011; Biwas et al., 2015, Colazo and Buschiazzo, 2015; Ligonja and Shrestha, 2015). High erosion rates result in the loss of soil and also changes the hydrological, erosional, biological, and geochemical cycles (Keesstra et al., 2012; Berendse et al., 2015; Decock et al., 2015; Brevik et al., 2015; Smith et al., 2015). Thus, there is a need to reduce the soil losses to achieve soil sustainability. However, although some findings show that straw, geotextiles, vegetation cover and tillage reduction are efficient strategies (Gimenez Morera et al., 2010; Cerdà et al., 2015; Lieskovský and Kenderessy, 2014; Taguas et al., 2015) there is still a need to find easy strategies for farmers to adopt in their fields that will protect, and also recover, their soils. Chipped branches are usually burned in many orchards to remove them from the fields. However, when they would be chipped and spread on the fields, they can be a source of organic matter, and in addition this might reduce soil losses and improve the water retention capacity of the soils (Mukherjee et al., 2014; Yazdanpanah et al., 2016). The hypothesis is that the chipped branches reduce soil loss. To test this hypothesis we selected 3 study sites in which chipped branches were applied, and paired sites with bare soil to check the changes introduced by the chipped branches on the soils. We selected 3 sites of the Cànyoles river watershed (Montesa municipality), SW Spain, with 10 plots in each site. At each site, 10 rainfall simulation experiments were carried out. Paired plots were selected in the nearby (less than 10 m in distance) orchard where the pruned branches were removed. Then, 60 rainfall simulation experiments at 55 mm h-1 of rainfall intensity during 1 hour were carried out in small 0.25 m2 plots to determine the soil particle detachment. The results show that in all