The evaluation method of soil-spring for the analyses of foundation structures on layered bedsoil

International Nuclear Information System (INIS)

Satoh, S.; Sasaki, F.

1985-01-01

When performing the finite element method analysis of foundation structures, such as mat slab of reactor buildings and turbine buildings, it is very important to evaluate and model the soil-spring mechanism between foundation and soil correctly. In this model, this paper presents the method in which soil-spring mechanism is evaluated from the theoretical solution. In this theory the semi-infinite elastic solid is assumed to be made of multi-layered soil systems. From the analytical example, it is concluded that the stress analysis of foundation structures on multi-layered soil systems cannot be evaluated by the conventional methods. (orig.)

The Frequency and Damping of Soil-Structure Systems with Embedded Foundation

International Nuclear Information System (INIS)

Ghannad, M. Ali; Rahmani, Mohammad T.; Jahankhah, Hossein

2008-01-01

The effect of foundation embedment on fundamental period and damping of buildings has been the title of several researches in three past decades. A review of the literature reveals some discrepancies between proposed formulations for dynamic characteristics of soil-embedded foundation-structure systems that raise the necessity of more investigation on this issue. Here, first a set of approximate polynomial equations for soil impedances, based on numerical data calculated from well known cone models, are presented. Then a simplified approach is suggested to calculate period and damping of the whole system considering soil medium as a viscoelastic half space. The procedure includes both material and radiation damping while frequency dependency of soil impedance functions is not ignored. Results show that soil-structure interaction can highly affect dynamic properties of system. Finally the results are compared with one of the commonly referred researches

Use of reinforced soil foundation (RSF) to support shallow foundation : technical summary report, November 2008.

Science.gov (United States)

2008-11-01

The presence of a weak soil supporting structural foundations results in low load bearing capacity and : excessive settlements, which can cause structural damage, reduction in durability, and/or deterioration in : performance level. Conventional trea...

Lateral response of pile foundations in liquefiable soils

Directory of Open Access Journals (Sweden)

Asskar Janalizadeh

2015-10-01

Full Text Available Liquefaction has been a main cause of damage to civil engineering structures in seismically active areas. The effects of damage of liquefaction on deep foundations are very destructive. Seismic behavior of pile foundations is widely discussed by many researchers for safer and more economic design purposes. This paper presents a pseudo-static method for analysis of piles in liquefiable soil under seismic loads. A free-field site response analysis using three-dimensional (3D numerical modeling was performed to determine kinematic loads from lateral ground displacements and inertial loads from vibration of the superstructure. The effects of various parameters, such as soil layering, kinematic and inertial forces, boundary condition of pile head and ground slope, on pile response were studied. By comparing the numerical results with the centrifuge test results, it can be concluded that the use of the p-y curves with various degradation factors in liquefiable sand gives reasonable results.

Investigation of structure and characteristics of soil for foundation design of gamma irradiators capacity 2 MCi

International Nuclear Information System (INIS)

Kukuh Prayogo; Hasriyasti Saptowati

2016-01-01

Soil investigation conducted before the work of irradiator building structural foundation design is initiated. Intake of sample was set at some point drill at Irradiator facility site to the disturbed soil layer or not disturbed. From the results of this soil investigation will be selected as alternative / types, the depth and dimensions of the foundation of the most economical but still safe. Soil investigation method used was Deep Boring, undisturbed and disturbed sampling, SPT ( Standard Penetration Test ), CPT ( Cone Penetration Test / Sondir ). Testing conducted in the field and in the laboratory of soil mechanics to determine the mechanical properties, soil layer thickness and other physical properties for calculation of the bearing capacity of the foundation. The results of the soil investigation at the three-point drill showed the average depth of the bedrock -19.33 m and adhesion 3163.88 kg / cm’. Test boring at point BH1 found the depth of the bedrock -19.33 m and adhesion 3163.88 kg / cm’. Test boring at point BH1 found the bedrock at a depth of 32 m with a maximum SPT value 16. from the data can be determined the appropriate type of foundation is bored pile. The foundation is the upper structure support which can lead to a reduction / settlement if its bearing capacity is not able to withstand the load on it. (author)

Effects of foundation modeling on dynamic response of a soil- structure system

International Nuclear Information System (INIS)

Chen, J.C.; Tabatabaie, M.

1996-07-01

This paper presents the results of our investigation to evaluate the effectiveness of different foundation modeling techniques used in soil-structure interaction analyses. The study involved analysis of three different modeling techniques applied to two different foundation configurations (one with a circular and one with a square shape). The results of dynamic response of a typical nuclear power plant structure supported on such foundations are presented

Chemical and geotechnical assessment of low organic foundation soils across the coastal area of Southwestern Nigeria

Science.gov (United States)

Adebisi, N. O.; Osammor, J.; Oluwafemi, O. S.

2018-04-01

Pressure on land use has caused great site development along the coastal area of south western Nigeria. However, research works for the purpose of evaluating appropriate depths of foundations in the area were without cognizance of engineering challenges that may ensue as a result of the organic content, and associated factors of the soils. This paper evaluates the compositional effects of the soils on foundation materials, and a phenomenological model of compressibility of fines during design and construction of problem-free foundations in the area. Thirty (30) disturbed soils were analysed for moisture content, grain size distribution, consistency limits, chloride, pH and sulphate, while the oedometer consolidation test was carried out on another 30 undisturbed soils. The stratigraphic sequence in the profile comprises medium dense to coarse grained silty clayey sand to 16.80 m depth, below loose grey organic silty clayey sand from the surface. Results show in most cases, that the foundation soils contain insignificant percentages (0.95-5.8%) of organic solids. Moisture content (44-70%), chloride (74.9 ppm), sulphate (420 ppm) ions concentration and pH (8.96) could enhance the corrosive potential of the soils. It is recommended that Portland cement concrete will be suitable in the environment. Foundation settlement with respect to surface area (0.028≤ mv ≤ 0.434m2MN-1 at 200 kNm-2; 0.038mv ≤ 0.776m2MN-1 at 400 kNm-2; 0.038≤ mv ≤ 0.879m2MN-1 at 800 kNm-2) ranges from low to medium compressibility with respect to consolidation pressure. Therefore, footings load need be spread over the soils, and foundation design need be based on site-specific soil information.

Theoretical and Experimental Substantiation for Applicability of a Damping Layer in a Foundation Slab Placed on Soil Bed

Directory of Open Access Journals (Sweden)

Kiselev Nikita

2016-01-01

Full Text Available Authors present the results of studies of innovative foundation structure. The idea of how to increase the operational quality of foundations and reduce the costs due to rational loading of the soil bed is numerically simulated. It is shown that the bending moment in the foundation slab depends on uneven settlements of the soil bed. It is proposed to stabilize the deformable soil bed by the damping layer placed under the slab footing in the zones with minor settlements. Considered is the concept of the damping layer in the foundation slab placed on the soil bed (DLS. The in-situ test for DLS-clayey bed interaction is described. Given are the results obtained after the experiments for DLS performance. The result of DLS implementation in designing the foundation of the 22-storeyed block of flats is considered. The expediency of DLS in comparison to standard foundations is presented.

Finite element modeling of a shaking table test to evaluate the dynamic behaviour of a soil-foundation system

International Nuclear Information System (INIS)

Abate, G.; Massimino, M. R.; Maugeri, M.

2008-01-01

The deep investigation of soil-foundation interaction behaviour during earthquakes represent one of the key-point for a right seismic design of structures, which can really behave well during earthquake, avoiding dangerous boundary conditions, such as weak foundations supporting the superstructures. The paper presents the results of the FEM modeling of a shaking table test involving a concrete shallow foundation resting on a Leighton Buzzard sand deposit. The numerical simulation is performed using a cap-hardening elasto-plastic constitutive model for the soil and specific soil-foundation contacts to allow slipping and up-lifting phenomena. Thanks to the comparison between experimental and numerical results, the power and the limits of the proposed numerical model are focused. Some aspects of the dynamic soil-foundation interaction are also pointed out

Stochastic analysis of uncertain thermal characteristic of foundation soils surrounding the crude oil pipeline in permafrost regions

International Nuclear Information System (INIS)

Wang, Tao; Zhou, Guoqing; Wang, Jianzhou; Zhao, Xiaodong

2016-01-01

Highlights: • The influence of stochastic properties and conditions on permafrost foundation was investigated. • A stochastic analysis for the uncertain thermal characteristic of crude oil pipe is presented. • The mean temperature and standard deviation of foundation soils are obtained and analyzed. • Average standard deviation and maximum standard deviation of foundation soils increase with time. - Abstract: For foundation soils surrounding the crude oil pipeline in permafrost regions, the soil properties and the upper boundary conditions are stochastic because of complex geological processes and changeable atmospheric environment. The conventional finite element analysis of thermal characteristics for crude oil pipeline is always deterministic, rather than taking stochastic parameters and conditions into account. This study investigated the stochastic influence of an underground crude oil pipeline on the thermal stability of the permafrost foundation on the basis of a stochastic analysis model and the stochastic finite element method. A stochastic finite element program is compiled by Matrix Laboratory (MATLAB) software, and the random temperature fields of foundation soils surrounding a crude oil pipeline in a permafrost region are obtained and analyzed by Neumann stochastic finite element method (NSFEM). The results provide a new way to predict the thermal effects of the crude oil pipeline in permafrost regions, and it shows that the standard deviations in temperature increase with time when considering the stochastic effect of soil properties and boundary conditions, which imply that the results of conventional deterministic analysis may be far from the true value, even if in different seasons. It can improve our understanding of the random temperature field of foundation soils surrounding the crude oil pipeline and provide a theoretical basis for actual engineering design in permafrost regions.

permeant properties of foundation soils in the basement complex ...

African Journals Online (AJOL)

Administrator

D10) is usually taken to be 10% of the size of the percentage finer. Discussion of Results. Grading curves for the studied foundation soils as shown in figure (2a-f), cover several log cycles of the semi-log paper This implies that a variety of ...

Discussion of the Method to Determine the Ultimate Bearing Capacity of Soil Foundation

Science.gov (United States)

Du, Peng; Liu, Xiaoling; Zhang, Yangfu

2017-12-01

Combining literature examples, this paper has carried out Contrastive analysis of the theoretical formula method and finite element method about the ultimate bearing capacity of foundation, To verify rationality and superiority of the incremental load method in finite element ABAQUS in solving the bearing capacity of foundation soil. The study can provide certain reference for practical engineering calculation and analysis of foundation bearing capacity.

Bearing capacity of helical pile foundation in peat soil from different, diameter and spacing of helical plates

Science.gov (United States)

Fatnanta, F.; Satibi, S.; Muhardi

2018-03-01

In an area dominated by thick peat soil layers, driven piles foundation is often used. These piles are generally skin friction piles where the pile tips do not reach hard stratum. Since the bearing capacity of the piles rely on the resistance of their smooth skin, the bearing capacity of the piles are generally low. One way to increase the bearing capacity of the piles is by installing helical plates around the pile tips. Many research has been performed on helical pile foundation. However, literature on the use of helical pile foundation on peat soil is still hardly found. This research focus on the study of axial bearing capacity of helical pile foundation in peat soil, especially in Riau Province. These full-scale tests on helical pile foundation were performed in a rectangular box partially embedded into the ground. The box is filled with peat soil, which was taken from Rimbo Panjang area in the district of Kampar, Riau Province. Several helical piles with different number, diameter and spacing of the helical plates have been tested and analysed. The tests result show that helical pile with three helical plates of uniform diameter has better bearing capacity compared to other helical piles with varying diameter and different number of helical plates. The bearing capacity of helical pile foundation is affected by the spacing between helical plates. It is found that the effective helical plates spacing for helical pile foundation with diameter of 15cm to 35cm is between 20cm to 30cm. This behaviour may be considered to apply to other type of helical pile foundations in peat soil.

Experimental Study on Vacuum Dynamic Consolidation Treatment of Soft Soil Foundation

Science.gov (United States)

Fu-lai, Ni; Xin, Wen; Xiao-bin, Zhang; Wei, Li

2017-11-01

In view of the deficiency of the saturated silt clay foundation reinforced by the dynamic consolidation method, combination the project of soft foundation treatment test area in Tangshan, the reaserch analysed indexes, included groundwater level, pore water pressure, settlement about soil layer and so on, by use of field tests and indoor geotechnical tests, The results showed that the whole reinforcement effect with vacuum dynamic compaction method to blow fill foundation is obvious, due to the result of vacuum precipitation, generally, the excess pore water pressure can be dissipated by 90% above in 2 days around and the effective compaction coefficient can reached more than 0.9,the research work in soft foundation treatment engineering provide a new method and thought to similar engineering.

Seismic soil-structure interaction of foundations with large piles

International Nuclear Information System (INIS)

Zeevaert, L.

1996-01-01

In seismic regions with soft soil deposits subjected to ground surface subsidence, there is the necessity to support the weight of constructions on large diameter piles or piers hearing on deep firm strata. To justify the action of these elements working under flexo compression and shear, it is necessary to perform calculations of soil pile interaction from a practical engineering point of view and estimate the order of magnitude of the forces and displacements to which these elements will be subjected during the seismic action assigned to the foundation. In this paper we defined a pier as a large diameter pile constructed on site. Furthermore, in the seismic analysis it is necessary to evaluate the seismic pore water pressure to learn on the effective seismic soil stresses close to the ground surface. (author)

Dynamic Soil-Pile Interaction for large diameter monopile foundations

DEFF Research Database (Denmark)

Zania, Varvara

2013-01-01

of the study is to analyse the dynamic interaction of the soil and a single pile embedded in it by accounting for the geometric and stiffness properties of the pile. In doing so, a semi – analytical approach is adopted based on the fundamental solution of horizontal pile vibration by Novak and Nogami (1977...... eigenfrequencies of the soil layer do not affect the soil – pile interaction. The decrease of the eigefrequency of the OWT depends on the aforementioned variation of the dynamic stiffness and the slenderness ratio of the monopile.......Monopile foundations have been used in a large extent to support offshore wind turbines (OWT), being considered as a reliable and cost effective design solution. The accurate estimation of their dynamic response characteristics is essential, since the design of support structures for OWTs has been...

Natural Frequencies of Wind Turbines on Monopile Foundations in Clayey Soils

DEFF Research Database (Denmark)

Andersen, Lars Vabbersgaard; Vahdatirad, Mohammadjavad; Sichani, Mahdi Teimouri

2012-01-01

A comprehensive study is performed on the stiffness of a monopile foundation supporting an offshore wind turbine in undrained, over-consolidated clay having a spatial variation of the soil properties. The undrained shear strength is considered as a stochastic field with increasing mean value over...

Evaluation of soil-structure interaction for structures subjected to earthquake loading with different types of foundation

Directory of Open Access Journals (Sweden)

Elwi Mohammed

2018-01-01

Full Text Available However though the structures are supported on soil, most of the designers do not consider the soil structure interaction and its subsequent effect on structure during an earthquake. Different soil properties can affect seismic waves as they pass through a soil layer. When a structure is subjected to an earthquake excitation, it interacts the foundation and soil, and thus changes the motion of the ground. It means that the movement of the whole ground structure system is influenced by type of soil as well as by the type of structure. Tall buildings are supposed to be of engineered construction in sense that they might have been analyzed and designed to meet the provision of relevant codes of practice and building bye-laws. IS 1893: 2002 “Criteria for Earthquake Resistant Design of Structures” gives response spectrum for different types of soil such as hard, medium and soft. An attempt has been made in this paper to study the effect of Soil-structure interaction on multi storeyed buildings with various foundation systems. Also to study the response of buildings subjected to seismic forces with Rigid and Flexible foundations. Multi storeyed buildings with fixed and flexible support subjected to seismic forces were analyzed under different soil conditions like hard, medium and soft. The buildings were analyzed by Response spectrum method using software SAP2000. The response of building frames such as Lateral deflection, Story drift, Base shear, Axial force and Column moment values for all building frames were presented in this paper.

Prognosis of radioactive wastes quantity in soils of new safety confinement foundation area

International Nuclear Information System (INIS)

Klyuchnikov, A.A.; Panasyuk, N.I.; Podbereznyj, S.S.; Skorbun, A.D.; Levin, G.V. and eds.

2006-01-01

or the first time a scientific founded calculation of radioactive wastes (radioactive soils) quantities at the places of New Safety Confinement foundation building has been given, and a map of bedding is shown. An example of construction of geoinformation system, created using ArcGIS 8.3 for analysing of soils radioactive contamination in the 'Ukryttya' object area of Chernobyl NPP have been examined

Influence of pile–soil interaction on the dynamic properties of offshore wind turbines supported by jacket foundations

DEFF Research Database (Denmark)

Yi, Jin-Hak; Kim, Sun-Bin; Yoon, Gil-Lim

2015-01-01

Monopiles are the most widely utilized foundation for offshore wind turbines (OWTs) in shallow waters. However, jacket-type foundations are being considered as one of the good alternatives to monopole foundations for relatively deep water in the range of 25–50 m of water depth. Jacket structures...... are conventionally used in the oil and gas industry. However, there are still several issues unsolved for utilization of jacket structures for OWTs including pile–soil-interaction (PSI) effects, dynamically stable design, installation, and so on. In this study,the effects of pile–soil interaction on the dynamic...

Foundation Structure

DEFF Research Database (Denmark)

2009-01-01

Method of installing a bucket foundation structure comprising one, two, three or more skirts, into soils in a controlled manner. The method comprises two stages: a first stage being a design phase and the second stage being an installation phase. In the first stage, design parameters are determined...... relating to the loads on the finished foundation structure; soil profile on the location; allowable installation tolerances, which parameters are used to estimate the minimum diameter and length of the skirts of the bucket. The bucket size is used to simulate load situations and penetration into foundation...

Suitability of natural soils for foundations for surface facilities at the prospective Yucca Mountain Nuclear Waste Repository

International Nuclear Information System (INIS)

Ho, D.M.; Sayre, R.L.; Wu, C.L.

1986-11-01

In this report, the natural soils at the Yucca Mountain site are evaluated for the purpose of assessing the suitability of the soils for the foundations of the surface facilities at the prospective repository. The areas being considered for locating the surface facilities are situated on an alluvial plain at the base of Yucca Mountain. Preliminary parameters for foundation design have been developed on the basis of limited field and laboratory study of soils at four test pit locations conducted during May and June 1984. Preliminary recommendations for construction are also included in this report. The gravel-sand alluvial deposits were found to be in a dense to very dense state, which is suitable for foundations of the surface facilities. The design parameters described in this report have been developed for conceptual design, but need to be verified before final design

Research on the Horizontal Displacement Coefficient of Soil Surrounding Pile in Layered Foundations by Considering the Soil Mass’s Longitudinal Continuity

Directory of Open Access Journals (Sweden)

Yao Wen-Juan

2013-01-01

Full Text Available When utilizing the p-y curve to simulate the nonlinear characteristics of soil surrounding pile in layered foundations, due to having not taken into account the soil mass’s longitudinal continuity, the calculation deviation of horizontal displacement increases with the growth of a load. This paper adopted the layered elasticity system theory to consider the soil mass’s longitudinal continuity, as well as utilizing the research method for layered isotropic bodies, assuming that the horizontal resistance is evenly distributed around the perimeter of the pile's cross-section. Then an appropriate transfer matrix method of horizontal displacement coefficient for the soil surrounding pile in layered foundations was established. According to the calculation principle of finite element equivalent load, the horizontal displacement coefficient matrix was deduced as well as providing a corrected formula for the horizontal displacement of soil surrounding pile through the p-y curve method when the external load was increased. Following the established model, a program was created which was used for calculating and analyzing the horizontal displacement coefficient matrix of three-layered soil in order to verify this method’s validity and rationale. Where there is a relatively large discrepancy in the soil layers’ properties, this paper’s method is able to reflect the influence on the layered soil’s actual distributional difference as well as the nearby soil layers’ interaction.

Scanning electronic microscopy on clays in soils used as road foundations

International Nuclear Information System (INIS)

Barelli, N.

1982-01-01

The scanning electron microscope (SEM) proves to be ideally suited for studying the morphology, texture and fabric of clays in soils used as road foundation. It is also seen that certain samples are easier to examine by SEM because of their larger crystallite sizes, better crystallinities and open textures. (C.L.B.) [pt

The importance of defining the geometry of foundations of soil layers for dynamic analysis of Colosseum

International Nuclear Information System (INIS)

Beste, H-J.; Clemente, P.; Conti, C.; D'Ovidio, G.; Nakamura, Y.; Orlando, L.; Rea, R.; Rovelli, A.; Valente, G.

2015-01-01

By the comparison between tests and analyses, the dynamic characterization was performed, in order to obtain the map of elastic modules for soil Colosseum interaction. The accuracy for foundations and soil is lower than for monument, due ti unknown exact geometry underground. For foundations, a high variability was found of elasticity modules, which was referred to variable damage of concrete for cracking in time. For soil layers, different definitions exist, and we are interested in the best. The vibrations produced by trains are depending on the underground geometry too. The analyses are performed with traditional convoys running on Metro B and C, for the vibrations knowledge on RA XLVII and on ground felt by pedestrians.

Vertical Dynamic Stiffness of Offshore Foundations

DEFF Research Database (Denmark)

Latini, Chiara; Cisternino, Michele; Zania, Varvara

2016-01-01

Nowadays, pile and suction caisson foundations are widely used to support offshore structures which are subjected to vertical dynamic loads. The dynamic soil-structure interaction of floating foundations (foundations embedded in a soil layer whose height is greater than the foundation length) is ...

Effects of the Length of Jet Grouted Columns and Soil Profile on the Settlement of Shallow Foundations

Directory of Open Access Journals (Sweden)

Zaheer Ahmed Almani

2012-07-01

Full Text Available In this paper, the effect of length of jet grouted columns and varying soil profile under shallow foundations of buildings constructed on the liquefiable ground was studied. The isolated shallow footing pad which supports a typical simple frame structure was constructed on the liquefiable ground. This ground was reinforced with jet grouted column rows under the shallow foundations of structure. The system was modeled as plane-strain using the FLAC 2D (Fast Lagrangian Analysis of Continua dynamic modelling and analysis code. This case focuses on the length of jet grouted columns in a soil profile and the effect of soil profiles of varying thickness on the settlements of building structure when the soil is liquefied during an earthquake. The results show that liquefaction-induced large settlements of shallow foundation of building decrease to tolerable limits with the increase in the length of columns. For soil profiles, with a relatively thinner liquefiable layer, a certain minimum length of columns (extended in base non liquefiable layer is required to meet the settlement tolerable limits. For soil profiles, with a relatively thicker liquefiable layer, this length should be equal to the thickness of the liquefiable layer from the footing base plus some extension in the base non liquefiable dense layer. In the soil profile with the base liquefiable layer underlying the non liquefiable layer, settlements could not be reduced to the tolerable limits even with columns of relatively larger length which may be critical.

Dynamic soil-structure interaction of monopod and polypod foundations

DEFF Research Database (Denmark)

Andersen, Lars Vabbersgaard

2016-01-01

within the time domain, frequency-independent lumped-parameter models are developed. The paper proposes a decision criterion for determination of which components must be included within a lumped-parameter model in order to account for the structure–soil–structure interaction in an adequate and efficient......The paper concerns the importance of through–soil coupling for structures having foundations with more footings. First, a model for dynamic analysis of polypod footings is established in the frequency domain, employing Green’s function for wave propagation in a layered half-space. To allow analysis...

Soil non-linearity and its effect on the dynamic behaviour of offshore platform foundations

Energy Technology Data Exchange (ETDEWEB)

Madshus, Christian

1997-07-01

This thesis focuses on non-linear soil response to the type of cyclic loading experienced under offshore gravity base platform foundations. These loads are dominated by a cyclic component around the main wave frequency, which may well mobilize soil non-linearity under severe sea-states. Superimposed on this main component are lower level higher frequency loads caused by resonant oscillations of the platform. The thesis presents results of specially designed triaxial tests to simulate this loading condition. The tests simultaneously applied two cyclic load components at different frequencies and amplitudes. The measured soil response to each component has been isolated through a frequency domain separation. It was found that the soil responds to the superimposed high frequency low level component as if the soil had a cyclically time-varying stiffness. If the superimposed component does not lead to load reversals, this stiffness variation is controlled by the frequency and amplitude of the main load component and by the hysteretic non-linearity of the soil. If the superimposed component causes reversals, the influence of the hysteretic non-linearity on the stiffness variation is reduced. The higher the degree of reversal, the more this influence it taken over by the variation in the instantaneous unloading-reloading stiffness of the soil. It was also found that this type of two-frequency cyclic soil testing is generally superior over conventional single-frequency testing in the way it enforces the soil to reveal several of its inherent properties not deducible from ordinary tests. Benefits of analyzing non-linear response in the frequency domain is demonstrated throughout this thesis. The ability of various theoretical soil models to simulate the observed soil behaviour under two-frequency cyclic loading has, been investigated through numerical analyses. It was found that only those models that are based on kinematic hardening are able to reproduce what was observed

Seismic response of bridge pier on rigid caisson foundation in soil stratum

Science.gov (United States)

Tsigginos, C.; Gerolymos, N.; Assimaki, D.; Gazetas, G.

2008-03-01

An analytical method to study the seismic response of a bridge pier supported on a rigid caisson foundation embedded in a deep soil stratum underlain by a homogeneous half space is developed. The method reproduces the kinematic and inertial responses, using translational and rotational distributed Winkler springs and dashpots to simulate the soil-caisson interaction. Closed-form solutions are given in the frequency domain for vertical harmonic S-wave excitation. Comparison with results from finite element (FE) analysis and other available solutions demonstrates the reliability of the model. Results from parametric studies are given for the kinematic and inertial responses. The modification of the fundamental period and damping ratio of the bridge due to soil-structure interaction is graphically illustrated.

Improved Performance of Connected Foundations for Resilient Energy Transmission Infrastructure in Soft Soils

Directory of Open Access Journals (Sweden)

Doohyun Kyung

2015-12-01

Full Text Available The connected foundation is an effective structural type of foundation that can improve the sustainability of electrical transmission towers in soft soils to serve as a resilient energy supply system. In this study, the performance of electrical transmission towers reinforced with connected beams was investigated using a series of field load tests. Model transmission tower structures were manufactured and adopted into the tests. Based on the load capacity mobilization and failure mechanism, a criterion to define the load carrying capacity for connected foundation was proposed. It was found that the performance of connected foundation varies with the mechanical property of connection beam. The load capacity and differential settlement increased and decreased, respectively, with increasing connection beam stiffness. Such effect of connection beam was more pronounced as the height of load application point or tower height (zh increases. Based on the load test results, a design model was proposed that can be used to evaluate the sustainable performance and load carrying capacity of connected foundations. Field load tests with prototype transmission tower structure models were conducted to check and confirm the performance of connected foundation and the proposed design method.

Experimental study on the foundation of soft soil solidification formula based on the Design - Expert software search

Science.gov (United States)

Qian, Chaojun; Li, Dahua; Zhang, xian; Zhou, Dongqing; Zhang, Baoliang

2017-08-01

Xuan city + 1100 kv search for converter station in Anhui province, in the process of foundation treatment, there is a cloth with a large number of lacustrine soft soil can not reach the need of engineering construction, so we want to cure the soft soil. By combining ratio of blast furnace slag (GGBS), gypsum, exciting agent CaO as a main curing agent for combination of reinforcing soft soil, the indoor unconfined compressive strength test, the influence factors on blast furnace slag, exciting agent and dosage of gypsum as impact factors, response value is 7 d and 28 d unconfined compressive strength of solidified soil, the experimental method is the Box - Behnken. The results show that the 7 d gypsum and the interaction of the blast furnace slag is obvious; 28 d exciting agent and gypsum interaction is obvious. By the analysis plaster, CaO, GGBSIn 7 d optimal proportion is 3.71%, 3.62%, 12.18%, the actual strength of the solidified soil age 1479.33 kPa; 28 d optimal proportion was 4.08%, 4.50%, 11.6%, the actual strength of the solidified soil age 2936.78 kPa. In the soil and the water curing effect of GGBS solidified soil, thereby GGBS this is a kind of new solidification material that can be used as the engineering foundation treatment of soft soil stabilizer has a certain value.

The Research on Subsidence Prediction of Soils Around Deep Foundation Pit

Directory of Open Access Journals (Sweden)

Ge LIU

2014-12-01

Full Text Available Deep foundation pit will cause settlement of surround buildings in the process of excavation. When the settlement is excessive, it will give rise to safety issues. Subsidence monitoring has become an important measure to ensure the safety of deep foundation pits. But in current subsidence monitoring engineering, the costs of wiring, unwiring and installation are particularly high. This paper proposes a portable wireless data transmission device in forecasting and early warning of settlement deformation of soils around deep foundation pits. We solve the problem by adopting the means of wireless communication to replace the cable transmission link part. The device does not rely on any personal computers. Instead, it can directly deal with the collected data through grey prediction GM (1, 1 mathematical model, neural network and interpolation model to give short-term, medium- term and long-term forecasts, respectively. Additionally it is able to set a threshold value. Once the forecast data reach the threshold, the device can issue alert and achieve the target of reminding technicians, so as to provide reliable basis to prevent and reduce disasters.

Evaluation of the dynamic responses of high rise buildings with respect to the direct methods for soil-foundation-structure interaction effects and comparison with the approximate methods

Directory of Open Access Journals (Sweden)

Jahangir Khazaei

2017-08-01

Full Text Available In dynamic analysis, modeling of soil medium is ignored because of the infinity and complexity of the soil behavior and so the important effects of these terms are neglected, while the behavior of the soil under the structure plays an important role in the response of the structure during an earthquake. In fact, the soil layers and soil foundation structure interaction phenomena can increase the applied seismic forces during earthquakes that has been examined with different methods. In this paper, effects of soil foundation structure interaction on a steel high rise building has been modeled using Abaqus software for nonlinear dynamic analysis with finite element direct method and simulation of infinite boundary condition for soil medium and also approximate Cone model. In the direct method, soil, structure and foundation are modeled altogether. In other hand, for using Cone model as a simple model, dynamic stiffness coefficients have been employed to simulate soil with considering springs and dashpots in all degree of freedom. The results show that considering soil foundation structure interaction cause increase in maximum lateral displacement of structure and the friction coefficient of soil-foundation interface can alter the responses of structure. It was also observed that the results of the approximate methods have good agreement for engineering demands.

STUDY ON THE REASONABLE EVALUATION OF SOIL PROPERTIES APPLIED IN THE DESIGN OF SHINSO FOUNDATION (JAPANESE STYLE CAISSON TYPE PILE) ON THE SLOPE

Science.gov (United States)

Yasuzato, Toshinori; Samizo, Junichi; Maeda, Yoshito; Abe, Tetsuo; Matsuki, Satoshi; Okutani, Junpei

The objective of this study is to find ways to maximize the design economy of the shinso foundation (Japanese style caisson type pile) on the rock slope through an evaluation of strength properties of the rock before and after plasticity. We investigate the influence of soil properties on the design result by carrying out experiments which give the soil properties before and after plasticity and by doing parametric studies on the soil properties. Experiment using small-scale shinso foundation is performed to verify the validity of result of examinations. Comparison between the experiment and the analytical result reveals the bearing capacity characteristics of the shinso foundation on the slope and gives new insights on the more economical design of the shinso foundation.

Seismic behavior of NPP structures subjected to realistic 3D, inclined seismic motions, in variable layered soil/rock, on surface or embedded foundations

International Nuclear Information System (INIS)

Jeremić, B.; Tafazzoli, N.; Ancheta, T.; Orbović, N.; Blahoianu, A.

2013-01-01

Highlights: • Full 3D, inclined, incoherent seismic motions used for modeling SSI of an NPP. • Analyzed effects of variable and uniform soil/rock layering profiles on SSI. • Surface and embedded foundations were modeled and differences analyzed. - Abstract: Presented here is an investigation of the seismic response of a massive NPP structures due to full 3D, inclined, un-correlated input motions for different soil and rock profiles. Of particular interest are the effects of soil and rock layering on the response and the changes of input motions (frequency characteristics) due to such layering. In addition to rock/soil layering effects, investigated are also effects of foundation embedment on dynamic response. Significant differences were observed in dynamic response of containment and internal structure founded on surface and on embedded foundations. These differences were observed for both rock and soil profiles. Select results are used to present most interesting findings

Monitoring of Deep Foundation Pit Support and Construction Process in Soft Soil Area of Pearl River Delta

Science.gov (United States)

Weiyi, Xie; Pengcheng

2018-03-01

The deep foundation pit supporting technology in the soft soil area of the Pearl River Delta is more complicated, and many factors influence and restrict it. In this project as an example, according to the geological conditions and the surrounding circumstances, the main foundation using bored piles and pre-stressed anchor cable supporting structure + five axis cement mixing pile curtain supporting form; partial use of double row piles supporting structure + five axis cement mixing pile curtain support type. Through the monitoring results of construction show that the foundation pit, the indicators of environmental changes are in the design range, the supporting scheme of deep foundation pit technology is feasible and reliable.

The Effect of Mechanical Anisotropy and Heterogeneity of Shear Strength Parameters of Soils on Drained Bearing Capacity of Shallow Foundations

Directory of Open Access Journals (Sweden)

R. Jamshidi Chenari

2017-09-01

Full Text Available Natural formation of soil deposits causes heterogeneity and anisotropy in their strength and stiffness properties. However, most soils in their natural states exhibit some anisotropy with respect to shear strength and heterogeneity with respect to the depth. In this paper, the standard Mohr- Coulomb constitutive law is generalized to anisotropic version in order to consider the effect of cohesion anisotropy of soil. Random field theory coupled with finite difference method was utilized in Monte Carlo simulations with considering the effect of auto-correlation and cross correlation between strength parameters of soil, in order to calculate the bearing capacity of shallow foundation in a strain controlled scheme. The results showed that the bearing capacity of shallow foundation decreases with increasing in variability of strength parameters and increases with increasing in anisotropy ratio.

Experimental study of collapsing properties of the compacted soil foundation of auto-road embankment

Directory of Open Access Journals (Sweden)

Yushkov Boris Semenovich

2014-06-01

Full Text Available The loess collapsing soils are practically ubiquitously distributed in the Perm region. They occupy about 30% of the region area. The mass construction of buildings and structures of different purposes is conducted there. Design and construction of auto-roads on the collapsing soils by ensuring their strength and normal operation is one of the most important and difficult problems of the modern construction. It is recommended to eliminate collapsing properties of soils within the entire collapsing strata with the use of deep compaction by rammers and presoaking of foundation soils, including that with deepwater explosions, chemical or thermal fixing. Multi-year practice of construction on the collapsing soils in the regions of our country showed that during erection of the various structures the removal of the powerful loess soil collapsibility is achieved with the help of methods described above, each of which is selected on the basis of the conditions and possibilities of application. This article describes the following tasks: 1. Study and generalization of the available experience of road construction on the loess soils; 2. Zoning and classification (typing of the loess strata; 3. Selection of the engineering-geological factors influencing the choice of method for compacting collapsing soils; 4. General provisions for road construction on the collapsing soils.

Seepage Study for Suction Installation of Bucket Foundation in Different Soil Combinations

DEFF Research Database (Denmark)

Koteras, Aleksandra Katarzyna; Ibsen, Lars Bo; Clausen, Johan Christian

2016-01-01

Research has proven the bucket foundation to be a feasible and an attractive solution for offshore wind turbines. Its potential derives partly from the cost-effectiveness due to the suction-assisted installation. The suction applied under the bucket lid produces a downward driving force and addit......Research has proven the bucket foundation to be a feasible and an attractive solution for offshore wind turbines. Its potential derives partly from the cost-effectiveness due to the suction-assisted installation. The suction applied under the bucket lid produces a downward driving force...... around the bucket skirt. The exceedance of critical suction might lead to installation failure due to formation of piping channels, which break the hydraulic seal between the skirt and soil. The excess pore pressure arising due to applied suction changes the effective stress, hence the penetration...

Study of Ground Treatment on Improvement of Pile Foundation Response in Liquefiable Soils

Directory of Open Access Journals (Sweden)

Chen Yulong

2016-05-01

Full Text Available In light of the disastrous the 2011 Tohoku Pacific Earthquake, the government of Japan has conducted studies to revise the seismic design code, and elevated peak ground accelerations have been adopted. Consequently, revisions on existing design to comply with the updated code are required for public projects that are still undergoing. The design safety needs to be reassessed, and implementation of strengthening measures is required if deemed necessary. For liquefaction countermeasures, ground treatment techniques that could increase the density of soils are often the preferable alternatives. The treatment usually increases the in-situ SPT-N or CPT-qc values, which in turn would increase the resistance of soil against liquefaction. For many public infrastructures in Japan supported by bored piles embedded partly or entirely in sandy soils, reevaluation of design safety against soil liquefaction would be required. In an assessment of possible retrofitting countermeasures for an infrastructure foundation, ground treatment has been considered. In this case study, effect of ground treatment on response of piles in liquefiable soils was investigated with numerical analyses using FLAC. Results provide insights into this ground treatment effect and useful information for consideration in future design or decision making.

NUMERICAL MODELLING OF CHICKEN-FOOT FOUNDATION

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Vipman Tandjiria

1999-01-01

Full Text Available This paper presents an analysis of the chicken-foot foundation using the finite element method. The foundation is considered as a reinforced concrete slab resting on a number of reinforced concrete pipes filled with and surrounded by in-situ soil. The soil and the pipes were modelled by isoparametric solid elements while the slab was modelled by isoparametric thick-plate elements. The study was intended to illustrate the basic mechanism of the chicken-foot foundation. Three cases have been considered for the parametric studies. The parameters investigated are thickness of slab, length of pipes and spacing between pipes. It is shown that such a foundation improves the behaviour of the raft foundation. It is also found that all the parameters used in the parametric studies influence the behaviour of the chicken-foot foundation.

Soil-structure Interaction in the Seismic Response of Coupled Wall-frame Structures on Pile Foundations

International Nuclear Information System (INIS)

Carbonari, S.; Dezi, F.; Leoni, G.

2008-01-01

This paper presents a study on the seismic response of coupled wall-frame structures founded on piles. A complete soil-structure interaction analysis is carried out with reference to a case study. Three different soils and seven real accelerograms are considered. Local site response analyses are performed in order to evaluate the incoming free-field motion at different depths and the ground motion amplifications. A numerical model, accounting for the pile-soil-pile interaction and for material and radiation damping, is used to evaluate the impedance matrix and the foundation input motion. The domain decomposition technique is adopted to perform time-domain seismic analyses introducing Lumped Parameter Models to take into account the impedance of the soil-structure system. Applications show that the rocking phenomena affect the behaviour of the structure by changing the base shear distribution within the wall and the frame and by increasing the structural displacements

INTERACTION OF A LONG PILE OF FINITE STIFFNESS WITH SURROUNDING SOIL AND FOUNDATION CAP

Directory of Open Access Journals (Sweden)

Ter-Martirosyan Zaven Grigor’evich

2015-09-01

Full Text Available The article presents the formulation and analytical solution to a quantification of stress strain state of a two-layer soil cylinder enclosing a long pile, interacting with the cap. The solution of the problem is considered for two cases: with and without account for the settlement of the heel and the underlying soil. In the first case, the article is offering equations for determining the stresses of pile’s body and the surrounding soil according to their hardness and the ratio of radiuses of the pile and the surrounding soil cylinder, as well as formulating for determining equivalent deformation modulus of the system “cap-pile-surrounding soil” (the system. Assessing the carrying capacity of the soil under pile’s heel is of great necessity. In the second case, the article is solving a second-order differential equation. We gave the formulas for determining the stresses of the pile at its top and heel, as well as the variation of stresses along the pile’s body. The article is also formulating for determining the settlement of the foundation cap and equivalent deformation modulus of the system. It is shown that, pushing the pile into underlying layer results in the reducing of equivalent modulus of the system.

Soil-structure interaction including nonlinear soil

OpenAIRE

Gicev, Vlado

2008-01-01

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

Foundation calculation for buildings and structures with two elastic characteristics of the foundation using features of Fourier transformsfor finite functions

Directory of Open Access Journals (Sweden)

Kurbatskiy Evgeniy Nikolaevich

2014-01-01

Full Text Available The problem of a beam resting on elastic foundation often occurs in the analysis of building, geotechnical, highway, and railroad structures. Its solution demands modeling of the mechanical behavior of the beam, the mechanical behavior of the soil as elastic subgrade and the form of interaction between the beam and the soil. The oldest, most famous and most frequently used mechanical model is the one devised by Winkler (1867, in which the beam-supporting soil is modeled as a series of closely spaced, mutually independent, linear elastic vertical springs, which, evidently, provide resistance in direct proportion to the deflection of the beam.The solution is presented for the problem of an Euler–Bernoulli beam supported by an infinite two-parameter Pasternak foundation. The beam is subjected to arbitrarily distributed or concentrated vertical loading along its length. Static response of a beam on an elastic foundation characterized by two parameters is investigated assuming, that the beam is subjected to external loads and two concentrated edge load. The governing equations of the problem are obtained and solved by pointing out that there is a concentrated edge foundation reaction in addition to a continuous foundation reaction along the beam axis in the case of complete contact in the foundation reactions of the two-parameter foundation model. The proposed method is based on the properties of Fourier transforms of the finite functions. Particular attention is paid to the problem, taking into account the deformation of soil areas outside the beam. The beam model with two foundation coefficients more realistically describes the behavior of strip footings under loading.

Pore pressure buildup and soil stress relaxation in monopile foundations of offshore wind converters; Porenwasserdruckaufbau und Bodenentfestigung um Pfahlgruendungen von Offshore-Windenergieanlagen

Energy Technology Data Exchange (ETDEWEB)

Cuellar, Pablo; Baessler, Matthias; Georgi, Steven; Ruecker, Werner [BAM Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany). Fachbereich 7.2 Ingenieurbau

2012-09-15

For the installation of wind turbines in the offshore environment and their foundation in the seabed it is customary to employ large-diameter steel piles, either in monopile or multi-pile configurations (jacket, tripod, etc..). The effects of cyclic lateral loading on the offshore piles and particularly the possibility of a progressive accumulation of residual pore water pressure within the saturated embedding soil are discussed in this article. Here it is shown that this can lead to significant changes of their behaviour under external loading, which can potentially compromise the foundation's stability or serviceability. Furthermore, some of the singular effects arising during a realistic storm of moderate magnitude as well as their potential for transient damages to the foundation's stiffness are addressed in the paper. For the investigation of these phenomena the authors have employed a coupled bi-phasic analytical model of the offshore foundation. The constitutive model employed for the seabed, in the frame of the theory of Generalized Plasticity, can reproduce some complex features of cyclic soil behaviour such as the tendency for a progressive densification under cyclic loading, which is responsible for the soil liquefaction phenomena in undrained conditions. Finally, some implications and specific recommendations for the design of offshore monopiles in the frame of the limit states are provided. (orig.)

Justification of parameters and selection of equipment for laboratory researches of a rammer's operating element dynamics in a soil foundation of a tank for oil and oil products storage

Science.gov (United States)

Gruzin, A. V.; Gruzin, V. V.; Shalay, V. V.

2017-08-01

The development of technology for a directional soil compaction of tank foundations for oil and oil products storage is a relevant problem which solution will enable simultaneously provide required operational characteristics of a soil foundation and reduce time and material costs to prepare the foundation. The impact dynamics of rammers' operating elements on the soil foundation is planned to specify in the course of laboratory studies. A specialized technique is developed to justify the parameters and select the equipment for laboratory researches. The usage of this technique enabled us to calculate dimensions of the models, of a test bench and specifications of the recording equipment, and a lighting system. The necessary equipment for laboratory studies was selected. Preliminary laboratory tests were carried out. The estimate of accuracy for planned laboratory studies was given.

Test work of sand compaction pile method on coal ash soil foundation. Sekitanbai jiban ni okeru sand compaction pile koho no shiken seko

Energy Technology Data Exchange (ETDEWEB)

Goto, K.; Maeda, S.; Shibata, T. (The Kansai Electric Power Co. Inc., Osaka (Japan))

1992-01-25

As an electric power supply source after the 1990 {prime}s, Nos. 5 and 6 units are additionally being constructed by Kansai Electric Power in its Himeji Power Station No.1 which is an exclusively LNG burning power station. The additional construction site of those units is of soil foundation reclaimed with coal ash which was used residual product in the existing No.1 through No.4 units. As a result of soil foundation survey, the coal ash layer and sand layer were known to be of material to be possibly liquidized at the time of earthquake. As measures against the liquidization, application was basically made of a sand compaction pile (SCP) method which is economical and abundant in record. However, that method was so short of record in the coal ash layer that its evaluation was difficult in soil reforming effect. Therefore, its applicability was evaluated by a work test on the site, which resulted in a confirmation that the coal ash as well as the sand can be sufficiently reformed by the SCP method. Started in September, 1991, the additional construction of Nos. 5 and 6 units in Himeji Power Station No.1 uses a 1.5m pitch SCP method to reform the soil foundation. 3 refs., 10 figs., 1 tab.

Prototype bucket foundation for wind turbines

DEFF Research Database (Denmark)

Ibsen, Lars Bo; Liingaard, Morten

The first full scale prototype bucket foundation for wind turbines has been installed in October 2002 at Aalborg University offshore test facility in Frederikshavn, Denmark. The suction caisson and the wind turbine have been equipped with an online monitoring system, consisting of 15 accelerometers...... and a real-time data-acquisition system. The report concerns the in service performance of the wind turbine, with focus on estimation of the natural frequencies of the structure/foundation. The natural frequencies are initially estimated by means of experimental Output-only Modal analysis. The experimental...... estimates are then compared with numerical simulations of the suction caisson foundation and the wind turbine. The numerical model consists of a finite element section for the wind turbine tower and nacelle. The soil-structure interaction of the soil-foundation section is modelled by lumped-parameter models...

The Finite Elements Method (FEM versus traditional Methods (TM, in the estimation of settlement and modulus of soil reaction for foundation slabs design on soils with natural or man-made cavities

Directory of Open Access Journals (Sweden)

Escolano-Sánchez, F.

2015-03-01

Full Text Available Direct foundations with continuous elements, such as slabs, provide more advantages than direct foundations with isolated elements, such as footings, and deep foundations, such as piles, in the case of soil with natural or man-made cavities. The slabs are usually designed by two-dimensional models which show their shape on the plant, on a lineal elastic support, represented by a modulus of soil reaction. Regarding the settlement estimation, the following article compares the Finite Elements Method (FEM versus the classical Method (CM to select the modulus of soil reaction used to design foundations slabs in sensitive soils and sites with possible cavities or collapses. This analysis includes one of these cavities in the design to evaluate the risk of fail.Las cimentaciones directas con elementos continuos «losas», tienen ventajas sobre las cimentaciones directas con elementos aislados «zapatas» y sobre las cimentaciones profundas «pilotes», frente a la presencia de terrenos problemáticos. Las losas se diseñan de forma habitual con modelos bidimensionales que representan su forma en planta, apoyada en un medio elástico y lineal, representado por un módulo de balasto. En el presente artículo se realiza un análisis comparativo, para la estimación de asientos, entre el Método de Elementos Finitos (FEM y el Método Clásico (MC, para la elección de los módulos de balasto que se utilizan en el diseño de losas de cimentación en terrenos con blandones y cavidades naturales o antrópicas. Este análisis considera el peligro de la presencia de una de estas cavidades dentro de su diseño, de esta forma, el riesgo de fallo puede ser valorado por ambos métodos.

Seismological analysis of group pile foundation for reactor

International Nuclear Information System (INIS)

Wang Demin.

1984-01-01

In the seismic analysis for reactor foundation of nuclear power plant, the local raise of base mat is of great significance. Base on the study of static and dynamic stability as well as soil-structure interaction of group piles on stratified soil, this paper presents a method of seismic analysis for group piles of reactor foundation at abroad, and a case history is enclosed. (Author)

Analysis of raft foundations for spent fuel pool in nuclear facilities

International Nuclear Information System (INIS)

Subramanian, K.V.; Kashikar, A.V.; Nath, C.; Shintre, C.C.

2005-01-01

Foundation rafts are analysed as a plate on elastic foundation with the representation of the foundation media using the Winkler idealisation i.e. series of linear uncoupled springs. The elastic constant of the Winkler springs is derived using the sub-grade modulus. However, the Winkler approach has limitations due to incompatibility of the deflections at raft-soil interface. The deflection of the raft at the point of contact and the deformation of the foundation media at this point of contact are incompatible in this approach. This particularly influences flexible rafts and further if the foundation media is soil. This paper discusses the analysis of raft, in general, and the analysis of the foundation raft for a Spent Fuel pool facility using 'variable k approach' where deformations at a node and influencing nodes are computed using Boussinesq's theory. The limitations stated above are overcome in this approach. Some studies on the sensitivity of parameters were carried out in the form of variation of moduli of elasticity of concrete and deformation modulus of soil. Analysis is also performed with conventional method using 'Winkler' soil springs. It is concluded that the Winkler model does not correctly predict the behaviour of the mat both qualitatively and quantitatively and could lead to underestimation of soil pressures leading to unconservative design. The approach involving soil structure interaction like the one presented here is hence recommended for important structures like those involved in Nuclear facilities. (authors)

On Foundation Improvement By Sand Replacement | Abam | Global ...

African Journals Online (AJOL)

This paper describes a simple foundation improvement method involving the replacement of poor foundation bearing soils with sand and the resultant improvement in bearing capacity and the minimization of settlement at the site of a large storage tank. Minimum thickness of sand replacement for various foundation loads ...

Causes of poor sealant performance in soil-gas-resistant foundations

International Nuclear Information System (INIS)

Scott, A.

1994-01-01

Sealants for radon-resistant foundation construction must seal the gap between concrete sections. Modern sealants have such low permeability that seal performance depends only on the permeability of the material that contacts the sealant. The surface permeability of concrete walls and floors was measured by a specially designed permeameter, which measures the airflow induced by a pressure difference across a temporary test seal applied to the surface. The permeability of bulk concrete is about 10 -15 m 2 . Areas free of surface defects had surface permeability ranging from 10 -14 to 10 -16 m 2 . However, surface defects are common on concrete wall surfaces, which increase the permeability to >10 -12 m 2 , too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Radon-resistant seals require either extended contact widths or mechanical removal of the surface layer and defects. (au) (4 refs.)

Vertical Capacity of Bucket Foundations in Undrained Soil

DEFF Research Database (Denmark)

Barari, Amin; Ibsen, Lars Bo

2014-01-01

Offshore wind turbine structures are traditionally founded on gravity concrete foundations or mono-piles. Bucket foundations were developed for the offshore oil and gas industry and are now being used in wind turbine construction. The loading in this application is characterized by a vertical loa...

THE NEW STRUCTURE OF A PLATE-PILE FOUNDATION

Directory of Open Access Journals (Sweden)

SAMORODOV О. V.

2016-01-01

Full Text Available Raising of problem. In the construction of high-rise buildings with significant loads on foundations and bedding at the base of not rocky soils tend to use the most common pile foundation to reduce the deformation and correspond to regulations [1] on the maximum permissible deformation. Monitoring of the stress-strain state (SSS pile foundations constructed buildings shows the existing reserves of bearing capacity on the one hand - soil bases of the second group of limit states, on the other - the foundation of the first group of limit states by regulating the SSS foundation during construction and exploitation. Therefore, are increasingly using more progressive structure of foundations consisting of piles and of plate, as well as methods for their construction [2 - 10], however, in their design there are a number of disadvantages associated with the ambiguity of the application of methods for the calculation of such structures, which allows to do only partial conclusions and recommendations. Purpose. Is proposing the new structure of a plate-pile foundation, which overcomes the drawbacks of the existing design solutions and methods of consruction their, as well as is proposing an engineering method of a determination of basic parameters. Conclusion. Is proposes the new structure of a plate-pile foundation and the method of a determination of basic parameters his in the design of a soil base to the maximum permissible deformation Su buildings. Efficiency of application this type plate-pile foundation obtained by rational distribution resistance between a plate and piles, when under load from the building to the first work fully incorporated plate that allows maximum deformed for plate, and then the piles - due to of the hinge connection with the plate. Thus, depending on the maximum permissible deformation for buildings resistance of plate part of a full load of more than 50%, that significantly reduces the consumption of concrete.

foundations on expansive soils introduction characteristic

African Journals Online (AJOL)

the swelling potential of expansive soils have been found to be: initial moisture content, .... behaviour of such huildin1?1>, it is difficult to give definite recommendations. ..... Structures in Black Cotton Soils, Central Building. Research Institute ...

Influence of the Soil-Structure Interaction on the Design of Steel-Braced Building Foundation

International Nuclear Information System (INIS)

Azarbakht, Alireza; Ashtiany, Mohsen Ghafory

2008-01-01

The modeling and analysis of the superstructure and the foundation for the seismic lateral loads are traditionally done separately. This assumption is an important issue in the design/rehabilitate procedures especially for the short period structures, i.e. steel braced or shear wall systems, which may result to a conservative design. By using more advance procedures, i.e. nonlinear static method, and the incorporation of the soil-structure interaction (SSI), the seismic demand in the lateral resisting system decreases and the design will become more economic. This paper includes an investigation about the influence of the SSI effect on the design of the steel-braced building foundation. The presented example is a three-bay three-storey steel braced frame. Three design methods based on the FEMA 356 guideline and the UBC 97 code are taken in to consideration. The three methods are: (1) linear static analysis based on the UBC 97 code assuming the fixed based condition; (2) linear static analysis based on the FEMA 356 guideline assuming the fixed based condition; and (3) nonlinear static analysis assuming both fixed and flexible based assumptions. The results show that the influence of the SSI on the input demand of the short period building foundations is significant and the foundation design based on the linear static method with the fixed base assumption is so conservative. A simple method is proposed to take the SSI effect in to consideration in the linear static procedure with the fixed base assumption, which is a common method for the engineers. The advantage of this proposed method is the simplicity and the applicability for the engineering purposes

FINOSEIS: A new approach to offshore-building foundation soil analysis using high resolution reflection seismic and Scholte-wave dispersion analysis

Science.gov (United States)

Wilken, Dennis; Wölz, Susanne; Müller, Christof; Rabbel, Wolfgang

2009-05-01

As part of the FINOSEIS project we present the development of new seismic acquisition and inversion concepts for offshore-building foundation soil analysis. FINOSEIS is a subproject of the FINO3 project, which is aimed at the construction of an offshore research platform based in 28 m water depth, hosting eight research projects dealing with offshore wind energy topics. Our investigations focus on the determination of seismic parameters and structural information of the building plot of FINO3. We infer the shear-wave velocity structure by exploiting the dispersive properties of Scholte-waves and use high resolution 2.5D reflection seismic acquisition to determine seismic stratigraphy in three dimensions. Our work is motivated regarding possible hazards to offshore foundations such as wind parks and the FINO3 platform itself, e.g. permanent mechanical load by wind- and wave-forces possibly leading to an impairment of the soil. We conducted a pre-investigation of the site of the future platform in order to help finding a suitable foundation soil by improving common site investigation methods. In May 2006 we did a survey covering an area of 2 km square employing high resolution 2.5D reflection seismic. Along three 2 km airgun profiles Scholte-waves were recorded with Ocean-Bottom-Seismometers. Spectral analysis of these led to pseudo-2D shear-wave velocity models along the profiles. The reflection seismic area is characterized by glacial stratigraphy and diffractions documented within the penetration range of 30 m. With respect to the topography of the identified horizons as well as to the distribution of diffracting objects, a suitable foundation area for the platform was suggested. The results of the Scholte-wave experiment provide valuable information for further inversion models as well as for the dimensioning of further measurements. We also implemented an inversion strategy using the particle swarm optimization method. The inverted layers of shear-wave velocity

Seismic response analysis of BWR buildings with embedded foundation

International Nuclear Information System (INIS)

Fukuzawa, R.; Chiba, O.; Tohdo, M.

1985-01-01

An investigation on the effect of various types of foundations embedded into soil deposit to the responses of BWR buildings is made. The frequency characteristics of massless rigid foundations such as impedance functions and input motion are first obtained, depending on the embedment depth, contact condition of side wall to soil and the thickness of surface layer in a two-layered soil. From the results it is found that the embedment depth and the thickness of surface layer have a distinct effect to the responses contributed by the impedance functions and the response values characterized by the input motions are obviously influenced by the embedment depth and the contact length of side wall to soil deposit. (orig.)

Cost-Effective Mass Production of Mono Bucket Foundations

DEFF Research Database (Denmark)

Gres, Szymon; Nielsen, Søren Andreas; Fejerskov, Morten

2015-01-01

for innovative and cost-effective design of Mono Bucket foundations. Established approach merges wind and wave load models, soil/structure interaction topics, structural optimization and installation/fabrication aspects, into software package with ability to perform optimal design of the individual foundations...

Response of two structures supported on common foundation

International Nuclear Information System (INIS)

Joshi, M.H.; Kulkarni, M.R.; Subramanian, K.V.; Palekar, S.M.; Warudkar, A.S.

1995-01-01

The present paper describes a parametric study of structure-structure interaction. The parameter's selected are stiffness and mass of the structures and stiffness of foundation medium. The paper concludes that in case of weak soils structures do interact through the common foundation and for rock-like foundation conditions there is no interaction between the structures. (author). 1 fig., 6 tabs

Prototype bucket foundation for wind turbines - natural frequency estimation

Energy Technology Data Exchange (ETDEWEB)

Ibsen, Lars Bo; Liingaard, M.

2006-12-15

The first full scale prototype bucket foundation for wind turbines has been installed in October 2002 at Aalborg University offshore test facility in Frederikshavn, Denmark. The suction caisson and the wind turbine have been equipped with an online monitoring system, consisting of 15 accelerometers and a real-time data-acquisition system. The report concerns the in service performance of the wind turbine, with focus on estimation of the natural frequencies of the structure/foundation. The natural frequencies are initially estimated by means of experimental Output-only Modal analysis. The experimental estimates are then compared with numerical simulations of the suction caisson foundation and the wind turbine. The numerical model consists of a finite element section for the wind turbine tower and nacelle. The soil-structure interaction of the soil-foundation section is modelled by lumped-parameter models capable of simulating dynamic frequency dependent behaviour of the structure-foundation system. (au)

Influence of foundation layering on soil-structure system motion

International Nuclear Information System (INIS)

Philippacopoulos, A.J.

1985-01-01

This paper is concerned with effects on structural motion due to layering of the foundation. Impedance functions for foundations which consist of a layer resting on a viscoelastic half-space are used on a simple 3-dof SSI system and transfer functions are generated. It is shown that the layering of the foundation effects the motion of the SSI system. These effects are more pronounced for shallow layers with large difference in shear wave velocity from the underlying half-space. (orig.)

FIELD INVESTIGATIONS OF PILED-RAFT FOUNDATIONS WITH SHORT-LENGTH CONIC PILES IN BUILDING AREAS OF MINSK

Directory of Open Access Journals (Sweden)

V. A. Sernov

2015-01-01

Full Text Available In recent time piled foundations are extensively applied due to an increase of storeys in buildings constructed in Minsk and load increment on the soil. Preference is given to this approach even in the case when relatively firm soil occurs in the top part of the foundation bed. In this case maximum usage of the foundation bed bearing capacity and reduction of foundation cost are considered as top-priority tasks for designers. One of the ways to increase the bearing capacity of piled foundations is the necessity to take into account resistance of foundation bed soil located under raft bottom. The raft as well as a shallow foundation is capable to transfer a significant part of building load into the soil. Such approach makes it possible to reduce a number of piles in the foundation or shorten their length. Then it results in shortening of the construction period and significant reduction in zero cycle. However up to the present moment reliable calculation methods that permit to take into account soil resistance in the raft base. An analysis of previous investigations on the matter executed by various researchers and a number of field investigations have been carried out with the purpose to develop the proposed methods.The paper presents results of field investigations on foundations consisting of short stamped tapered piles which are joined together with the help of the raft fragment. Strength and deformation characteristics of the bases are increasing while making such foundations in the fill-up soil. In this case the filled-up ground layer becomes a bearing layer both for piles and rafts as well. Improvement of high-plastic clay-bearing soil properties is ensured by ramming dry concrete mix under pile foot. The paper describes an experience on application of the piled-raft foundation in complicated engineering and geological conditions while constructing the Orthodox Church in Minsk.

Response of Rubble Foundation to Dynamic Loading

DEFF Research Database (Denmark)

Burcharth, H. F.; Ibsen, Lars Bo

1993-01-01

The soil beneath vertical monolithic structures is subjected to a combination of static load due to the submerged weight of the structure and stochastic non-stationary loads as a result of the wave loads on the vertical wall. The stress conditions in the soil below a foundation exposed to both...

Response of Rubble Foundation to Dynamic Loading

DEFF Research Database (Denmark)

Burcharth, H. F.; Ibsen, Lars Bo

1994-01-01

The soil beneath vertical monolithic structures is subjected to a combination of static load due to the submerged weight of the structure and stochastic non-stationary loads as a result of the wave loads on the vertical wall. The stress conditions in the soil below a foundation exposed to both...

Theoretical computation background for transformation of foundations using pile drains

Directory of Open Access Journals (Sweden)

Ter-Martirosyan Zaven

2017-01-01

Full Text Available In the design of foundations for buildings and structures of various purposes, including improved risk, weak water-saturated clay soils with low mechanical characteristics are often found on a construction site. One of the possible ways of using them as a foundation is to seal them in various ways, including using pile drains of sand or rock stone material that are capable of both absorbing the load at the base and accelerating the process of filtration consolidation. This paper describes an analytical solution to the problem of interaction between the pile and the mattress with the surrounding soil of the foundation, taking into account the possibility of expanding the pile shaft. Solutions are obtained for determining the stresses in the shaft of the pile drain and in the soil under the mattress. The solution takes into account the influence of the pre-stressed state of the foundation after compaction on the formation of a stress-strain state during the erection and operation of structures. The solutions are relevant for consolidating pile drains made of rubble or for jet grouting piles, the rigidity of which is comparable to the rigidity of the surrounding soil. The paper describes the technique for determining the characteristics of the strength and deformability of the converted foundation and the results of large-scale tests at the experimental site for the construction of a large energy facility in Russia.

FROM BASEMENTS AND FOUNDATIONS TO LEADING MODERN SCIENTIFIC SCHOOL

Directory of Open Access Journals (Sweden)

SEDIN V. L.

2016-10-01

Full Text Available Problem statement. Everything starts with the bases, both in philosophy and construction sense, Basements and Foundations Department was an essential part for the formation of Dnipropetrovsk Civil Engineering Institute. For its 85 years of existence, it was a reflection of development of the native institute later academy and the construction industry also in the whole. Thanks to a classical base and 40 years traditions of the scientific school, the department staff always did scientific basis and took part in the development of the state construction norms documents. Today, the department develops with considering the requirements of the International Society of Soil Mechanics and Geotechnical Engineering (ISSMGE, the science combining the engineering geology, studying the soil, soil mechanics, creating the model, designing of the foundation and subsurface structure with the use of the modern program complex, production technology works for foundation, monitoring of these works and the safety of the surrounding construction.

Research on the Properties of the Waste Glass Concrete Composite Foundation

Science.gov (United States)

Jia, Shilong; Chen, Kaihui; Chen, Zhongliang

2018-02-01

The composite foundation of glass concrete can not only reuse the large number of waste glass, but also improve the bearing capacity of weak foundation and soil with special properties. In this paper, the engineering properties of glass concrete composite foundation are studied based on the development situation of glass concrete and the technology of composite foundation.

Forest soils

Science.gov (United States)

Charles H. (Hobie) Perry; Michael C. Amacher

2009-01-01

Productive soils are the foundation of sustainable forests throughout the United States. Forest soils are generally subjected to fewer disturbances than agricultural soils, particularly those that are tilled, so forest soils tend to have better preserved A-horizons than agricultural soils. Another major contrast between forest and agricultural soils is the addition of...

Engineering Significant of Swelling Soils

OpenAIRE

Behzad Kalantari

2012-01-01

This study describes some of the most important swelling characters of expansive soils when used as foundation materials to support various types of civil engineering structures. Expansive soils are considered among difficult foundation materials and expand upon wetting and shrink upon losing moisture. They are considered problematic soils for architectural and civil engineers. These types of soils may cause minor to major structural damages to pavements as well as buildings. It is therefore ...

Soil-structure interaction analysis by Green function

International Nuclear Information System (INIS)

Muto, Kiyoshi; Kobayashi, Toshio; Nakahara, Mitsuharu.

1985-01-01

Using the method of discretized Green function which had been suggested by the authors, the parametric study of the effects of base mat foundation thickness and soil stiffness were conducted. There was no upper structure effects from the response and reaction stress of the soil by employing different base mat foundation thicknesses. However, the response stress of base mat itself had considerable effect on the base mat foundation stress. The harder the soil, became larger accelerations, and smaller displacements on the upper structure. The upper structure lines of force were directed onto the soil. In the case of soft soil, the reaction soil stress were distributed evenly over the entire reactor building area. Common characteristics of all cases, in-plane shear deformation of the upper floor occured and in-plane acceleration and displacement at the center of the structure become larger. Also, the soil stresses around the shield wall of the base mat foundation became large cecause of the effect of the shield wall bending. (Kubozono, M.)

RESEARCH OF THE FOUNDATION CONSOLIDATED BY DIFFERENT-SIZED HORIZONTAL ELEMENTS

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Isakova Elena Aleksandrovna

2016-05-01

Full Text Available The article is dedicated to the problem of geotechnics. The problems of the weak soil base are topical. Also there sometimes happen severe accidents of soil mass. A great number of such emergencies is of a progressive character, when a local crash leads to the crash of the whole construction. Tarring the soil with epoxy can ensure geotechnical safety of the basis. That’s why the improvement of this method is needed in order to reduce yielding of the base, create ground water cutoff or create building hoisting. In the article new structural solutions for reduction of settlement are presented. The authors suggest using the manufactured plane elements containing epoxy. Such elements have different sizes and lie underneath the foundation. Similar structural scheme can be used to reduce soil settlement. The authors carried out two series of plate-bearing model tests with manufactured plane epoxy elements. In the first series of tests the biggest element was closer to the foundation, the smallest element was closer to the biggest element. In the second series of tests the smallest element was closer to the foundation, the biggest element was closer to the smallest element. After the end of plate-bearing model tests the authors received values of the base settlement and the dependency diagrams “base settlement-soil pressure”. The new structural solution for reducing soil settlement proved to be effective. Settlement of base decreased sevenfold.

Geotechnical Properties of Makurdi Shale and Effects on Foundations

African Journals Online (AJOL)

Geotechnical Properties of Makurdi Shale and Effects on Foundations. IO Agbede, P Smart ... Ten disturbed soil samples were collected from a third site of a proposed site for a light building and subjected to engineering classification tests. Based on the outcome of the second set of experiments, a foundation other than the ...

Characteristic Behavior of Bucket Foundations

DEFF Research Database (Denmark)

Barari, Amin

political and industrial forces(particularly in northern Europe) supporting the development of the offshore wind industry. The overall aim of the research presented in this thesis was to improve the design of offshore wind turbine foundations. The work was divided into two main researchefforts: geotechnical...... reduce the risks and costsrelated to offshore geotechnics. The thesis examines: 1.Characteristic Behavior of Bucket Foundations 2. Modeling of Water Flow through Porous Media The outcomes of each of the research contributions are summarized in four research articles, either directly or indirectly...... engineering experiments to gain insight into the behavior of offshore bucket foundations, and development of methods to improve the study of infiltration intounsaturated soils, an important problem in geo-environmental engineering. The outcomes of the research have the potential to directly or indirectly...

INVESTIGATION OF STRAIN STATE OF BASE OF THE FRAGMENT’S MODEL OF THE PILE FOUNDATION DURING STAGED LOADING OF ITS ELEMENTS IN THE SOIL TANK

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SEDIN V. L.

2017-04-01

Full Text Available Summary. Purpose. Changes of stress strain state of the fragment’s model of the pile foundation’s base depending on load sequence change should be investigated. Methodology. There are laboratory three test runs of the fragment’s model of the pile foundation carried out at the soil tank, unlike staged of loading and square of weight square on the soil under the plate raft with the including of pile. Results. There are laboratory confirmations of change of strain-stress state of pile foundation base depending on its elements’ load sequence change and confirmations of the influence of piles preloading on their settlement reduction. Originality. Carried out series of tests under the spatial invert with step-by-step loading of model elements of pile foundation fragments (the II and III test runs showed that such sequence of foundation load allows it to take heavier loads under the condition of the same values of settlement. The model of pile foundation’s fragment with additional loading of pile (III test run showed that such sequence of foundation load allows it to take heavier loads in comparison to the I test run. Practical value. Upon condition of staged including of all elements of the pile foundation, prestressed strain state (additional skin frictions, around the model of the pile, at some point, which facilitates the movement of the pile’s model, not connected with the plate. There are laboratory confirmations of dependencies that the more the weight square under the plate is, the greater the displacement of pile’s fragment. This effect can be useful for preloading piles in the real building, and to help align the piles' settling within the limits of the pile field, before the transfer of operational loads.

Time-domain representation of frequency-dependent foundation impedance functions

Science.gov (United States)

Safak, E.

2006-01-01

Foundation impedance functions provide a simple means to account for soil-structure interaction (SSI) when studying seismic response of structures. Impedance functions represent the dynamic stiffness of the soil media surrounding the foundation. The fact that impedance functions are frequency dependent makes it difficult to incorporate SSI in standard time-history analysis software. This paper introduces a simple method to convert frequency-dependent impedance functions into time-domain filters. The method is based on the least-squares approximation of impedance functions by ratios of two complex polynomials. Such ratios are equivalent, in the time-domain, to discrete-time recursive filters, which are simple finite-difference equations giving the relationship between foundation forces and displacements. These filters can easily be incorporated into standard time-history analysis programs. Three examples are presented to show the applications of the method.

CENTRIFUGAL VIBRATION TEST OF RC PILE FOUNDATION

Science.gov (United States)

Higuchi, Shunichi; Tsutsumiuchi, Takahiro; Otsuka, Rinna; Ito, Koji; Ejiri, Joji

It is necessary that nonlinear responses of structures are clarified by soil-structure interaction analysis for the purpose of evaluating the seismic performances of underground structure or foundation structure. In this research, centrifuge shake table tests of reinforced concrete pile foundation installed in the liquefied ground were conducted. Then, finite element analyses for the tests were conducted to confirm an applicability of the analytical method by comparing the experimental results and analytical results.

On the influence of the embedment of the foundation and the layered media

International Nuclear Information System (INIS)

Ambrosini, R.D.; Danesi, R.F.

1995-01-01

The main objective of this paper is to contribute to determine the influence of both the embedment of the foundation and the layered media in the seismic response of building structures with prismatic rectangular foundations. A soil-structure interaction model was used for this purpose. A general beam formulation was adopted to represent the physical model of the structure and two lumped parameter models, were adopted to represent the soil and the interaction mechanisms. On the other hand, an equivalent half space model was added, that permits taking into account the layered elastic soil in the analysis. The results obtained show that the embedment of the foundation is a fundamental parameter that cannot be neglected in the analysis because the structure forces could be significantly underestimated. In connection with the layered soil it can be stated that this is not an important factor because the differences with the half space results are not significant. (author). 18 refs., 1 fig., 5 tabs

Structure-soil-structure interaction of nuclear structures

International Nuclear Information System (INIS)

Snyder, M.D.; Shaw, D.E.; Hall, J.R. Jr.

1975-01-01

Structure-to-structure interaction resulting from coupling of the foundations through the soil has traditionally been neglected in the seismic analysis of nuclear power plants. This paper examines the phenomenon and available methods of analytical treatment, including finite element and lumped parameter methods. Finite element techniques have lead to the treatment of through soil coupling of structural foundations using two dimensional plane strain models owing to the difficulty of considering three dimensional finite element models. The coupling problem is treated by means of a lumped parameter model derived from elastic half-space considerations. Consequently, the method is applicable to the interaction of any number of foundations and allows the simultaneous application of tri-directional excitation. The method entails the idealization of interacting structures as lumped mass/shear beams with lumped soil springs and dampers beneath each foundation plus a coupling matrix between the interacting foundations. Utilizing classical elastic half-space methods, the individual foundation soil springs and dampers may be derived, accounting for the effects of embedment and soil layering, analogous to the methods used for single soil-structure, interaction problems. The coupling matrix is derived by generating influence coefficients based on the geometric relationship of the structures using classical half-space solutions. The influence coefficients form the coupling flexibility matrix which is inverted to yield the coupling matrix for the lumped parameter model

Hygrothermal Simulation of Foundations: Part 1 - Soil Material Properties

Energy Technology Data Exchange (ETDEWEB)

Kehrer, Manfred [ORNL; Pallin, Simon B [ORNL

2012-10-01

The hygrothermal performance of soils coupled to buildings is a complicated process. A computational approach for heat transfer through the ground has been well defined (EN ISO 13370:2007, 2007), and simplified methods have been developed (Staszczuk, Radon, and Holm 2010). However, these approaches generally ignore the transfer of soil moisture, which is not negligible (Janssen, Carmeliet, and Hens 2004). This study is divided into several parts. The intention of the first part is to gather, comprehend and adapt soil properties from Soil Science. The obtained information must be applicable to related tasks in Building Science and validated with hygrothermal calculation tools. Future parts of this study will focus on the validation aspect of the soil properties to be implemented. Basic changes in the software code may be requested at this time. Different types of basement construction will be created with a hygrothermal calculation tool, WUFI. Simulations from WUFI will be compared with existing or ongoing measurements. The intentions of the first part of this study have been fulfilled. The soil properties of interest in Building Science have been defined for 12 different soil textures. These properties will serve as input parameters when performing hygrothermal calculations of building constructions coupled to soil materials. The reliability of the soil parameters will be further evaluated with measurements in Part 2.

Consolidation Theory for a Stone Column Composite Foundation under Multistage Loading

Directory of Open Access Journals (Sweden)

Shenggen Huang

2016-01-01

Full Text Available The consolidation theories considering instant load cannot fully reveal the consolidation mechanism of a stone column composite foundation used in the expressway embankments due to the time effect of loading; that is, the expressway embankments are often constructed in several stages for a long time. Meanwhile, owing to the special property that the pile-soil stress ratio is larger than 1, the consolidation theory for sand drain well foundation cannot be used directly in the consolidation analysis of stone column composite foundation. Based on the principle that the vertical load applied on the composite foundation is shared by the stone column and the surrounding soil, the governing solutions for the stone column composite foundation under a multistage load are established. By virtue of the separation of variables, the corresponding solutions of degree of consolidation for loading stage and maintaining load stage are derived separately. According to the Carrillo theorem, the solution for the average total degree of consolidation of entire composite foundation is also obtained. Finally, the reasonableness of the present solution has been verified by comparing the consolidation curve calculated by the present solution with that measured by site test.

Theoretical investigation of interaction between a rectangular plate and fractional viscoelastic foundation

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Chengcheng Zhang

2014-08-01

Full Text Available The interaction between plates and foundations is a typical problem encountered in geotechnical engineering. The long-term plate performance is highly dependent on the rheological characteristics of ground soil. Compared with conventional linear rheology, the fractional calculus-based theory is a more powerful mathematical tool that can address this issue. This paper proposes a fractional Merchant model (FMM to investigate the time-dependent behavior of a simply supported rectangular plate on viscoelastic foundation. The correspondence principle involving Laplace transforms was employed to derive the closed-form solutions of plate response under uniformly distributed load. The plate deflection, bending moment, and foundation reaction calculated using the FMM were compared with the results obtained from the analogous elastic model (EM and the standard Merchant model (SMM. It is shown that the upper and lower bound solutions of the FMM can be determined using the EM. In addition, a parametric study was performed to examine the influences of the model parameters on the time-dependent behavior of the plate–foundation interaction problem. The results indicate that a small fractional differential order corresponds to a plate resting on a sandy soil foundation, while the fractional differential order value should be increased for a clayey soil foundation. The long-term performance of a foundation plate can be accurately simulated by varying the values of the fractional differential order and the viscosity coefficient. The observations from this study reveal that the proposed fractional model has the capability to capture the variation of plate deflection over many decades of time.

Subsidence estimation of breakwater built on loosely deposited sandy seabed foundation: Elastic model or elasto-plastic model

Directory of Open Access Journals (Sweden)

Jianhua Shen

2017-07-01

Full Text Available In offshore area, newly deposited Quaternary loose seabed soils are widely distributed. There are a great number of offshore structures has been built on them in the past, or will be built on them in the future due to the fact that there would be no very dense seabed soil foundation could be chosen at planed sites sometimes. However, loosely deposited seabed foundation would bring great risk to the service ability of offshore structures after construction. Currently, the understanding on wave-induced liquefaction mechanism in loose seabed foundation has been greatly improved; however, the recognition on the consolidation characteristics and settlement estimation of loose seabed foundation under offshore structures is still limited. In this study, taking a semi-coupled numerical model FSSI-CAS 2D as the tool, the consolidation and settlement of loosely deposited sandy seabed foundation under an offshore breakwater is investigated. The advanced soil constitutive model Pastor-Zienkiewics Mark III (PZIII is used to describe the quasi-static behavior of loose sandy seabed soil. The computational results show that PZIII model is capable of being used for settlement estimation problem of loosely deposited sandy seabed foundation. For loose sandy seabed foundation, elastic deformation is the dominant component in consolidation process. It is suggested that general elastic model is acceptable for subsidence estimation of offshore structures on loose seabed foundation; however, Young's modulus E must be dependent on the confining effective stress, rather than a constant in computation.

Soil Storytelling: Developing a Seminar to Fuse Scientific Foundations with Artistic Expression

Science.gov (United States)

Chiartas, Jessica

2017-04-01

scientific foundations with artistic expression to simultaneously educate and entertain. As such, we have created a project-based seminar that 1) educates graduate students in scientific communication and the use of storytelling to develop positive, solutions based messaging that leads with clearly communicated, broader impacts and 2) facilitates the development of original media content to be hosted on an interactive website, highlighting the various ways that soil is connected to our everyday lives, overall health, and well-being. Tapping into the resources available in a university setting, we recruited students from across the sciences, arts and humanities and cross-collaborated to develop deliverable products - a website (in development), educational resources, original media content (infographics, short videos, short stories), as well as a well-defined curriculum that can easily be replicated at other universities or institutions.

Study of wind turbine foundations in cold climates

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-11-01

This report provides an overview of the processes at work in soil in cold climates and their effect on wind turbine foundations. Havsnaes wind farm consists of 48 turbines located in Jaemtland county in central Sweden. Havsnaes has provided an appropriate research environment to investigate the engineering challenges related to the design and construction of wind turbine foundations in sub-arctic conditions and the experienced gained from this project informs this report.

Altered Soil Properties Inhibit Fruit Set but Increase Progeny Performance for a Foundation Tree in a Highly Fragmented Landscape

Directory of Open Access Journals (Sweden)

Tanya M. Llorens

2018-04-01

Full Text Available Failing to test multiple or non-standard variables in studies that investigate the effects of habitat fragmentation on plant populations may limit the detection of unexpected causative relationships. Here, we investigated the impacts of habitat fragmentation on the pollination, reproduction, mating system and progeny performance of Eucalyptus wandoo, a foundation tree that is bird and insect pollinated with a mixed-mating system. We explored a range of possible causative mechanisms, including soil properties that are likely to be altered in the agricultural matrix of a landscape that has naturally nutrient-poor soils and secondary soil salinization caused by the removal of native vegetation. We found very strong negative relationships between soil salinity and fruit production, thus providing some of the first evidence for the effects of salinity on reproduction in remnant plant populations. Additionally, we found unexpectedly higher rates of seedling survival in linear populations, most likely driven by increased soil P content from adjacent cereal cropping. Higher rates of seed germination in small populations were related to both higher pollen immigration and greater nutrient availability. Trees in small populations had unexpectedly much higher levels of pollination than in large populations, but they produced fewer seeds per fruit and outcrossing rates did not vary consistently with fragmentation. These results are consistent with small populations having much higher insect abundances but also increased rates of self-pollination, combined with seed abortion mechanisms that are common in the Myrtaceae. This study highlights the need to better understand and mitigate sub-lethal effects of secondary soil salinity in plants growing in agricultural remnants, and indicates that soil properties may play an important role in influencing seed quality.

Excavationless Exterior Foundation Insulation Field Study

Energy Technology Data Exchange (ETDEWEB)

Schirber, T.; Mosiman, G.; Ojczyk, C.

2014-10-01

Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. However, such an approach can be very costly and disruptive when applied to an existing home, requiring deep excavation around the entire house. The NorthernSTAR Building America Partnership team implemented an innovative, minimally invasive foundation insulation upgrade technique on an existing home. The approach consisted of using hydrovac excavation technology combined with a liquid insulating foam. The team was able to excavate a continuous 4" wide by 4' to 5' deep trench around the entire house, 128 linear feet, except for one small part under the stoop that was obstructed with concrete debris. The combination pressure washer and vacuum extraction technology also enabled the elimination of large trenches and soil stockpiles normally produced by backhoe excavation. The resulting trench was filled with liquid insulating foam, which also served as a water-control layer of the assembly. The insulation was brought above grade using a liquid foam/rigid foam hybrid system and terminated at the top of the rim joist. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features, utility meters, and landscaping would be minimal or non-existent in an excavationless process.

Excavationless Exterior Foundation Insulation Field Study

Energy Technology Data Exchange (ETDEWEB)

Schirber, T. [NorthernSTAR, Minneaplolis, MN (United States); Mosiman, G. [NorthernSTAR, Minneaplolis, MN (United States); Ojczyk, C. [NorthernSTAR, Minneaplolis, MN (United States)

2014-09-01

Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. However, such an approach can be very costly and disruptive when applied to an existing home, requiring deep excavation around the entire house. The NorthernSTAR Building America Partnership team implemented an innovative, minimally invasive foundation insulation upgrade technique on an existing home. The approach consisted of using hydrovac excavation technology combined with liquid insulating foam. The team was able to excavate a continuous 4 inches wide by 4 feet to 5 feet deep trench around the entire house, 128 linear feet, except for one small part under the stoop that was obstructed with concrete debris. The combination pressure washer and vacuum extraction technology also enabled the elimination of large trenches and soil stockpiles normally produced by backhoe excavation. The resulting trench was filled with liquid insulating foam, which also served as a water-control layer of the assembly. The insulation was brought above grade using a liquid foam/rigid foam hybrid system and terminated at the top of the rim joist. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features, utility meters, and landscaping would be minimal or non-existent in an excavationless process.

Preliminary Report on the Effect of Pre-Boring on the Mobilized Friction Capacity of Pile Foundation Hydraulically Jacked into Expansive Soil

Directory of Open Access Journals (Sweden)

Budi G.S.

2015-01-01

Full Text Available Pre-drilling was performed to reduce lateral earth pressure generated by pile foundation hydraulically jacked into expansive soil. Nineteen prestressed-precast spun concrete pile with diameter of 800 mm were penetrated into expansive soil up the depth of 40 m. Pre-drilling with diameter of 700 mm was carried out up to the depth of 12.5 m. Penetration loads required to install the piles, which was displayed on the built-in pressure panel, were recorded every 1 m interval. The load that was consisted of merely shaft friction was then used to find out the mobilized skin friction between pile shaft and its surrounding soils. The calculated mobilized skin friction was correlated to the value of Standard Penetration Test (NSPT and compared to Decourt formula. The result shows that skin friction calculated using Decourt formula relatively conservative compared to those determined from the records of field penetration. The upper bound of mobilized skin friction can be defined by modifying Decourt formula.

Analysis of pile foundations under dynamic loads

International Nuclear Information System (INIS)

Waas, G.; Hartmann, H.G.

1981-01-01

A method is presented for the analysis of pile foundations which are subjected to horizontal dynamic loads from earthquakes, airplane impact, gas explosion or other sources. The motion of the pile cap and the pile forces are computed. - The loads may be applied to the pile cap or directly to the piles (e.g. by earthquake wave motion). The soil may be stratified and is considered to be an elastic or visco-elastic medium. The piles are assumed vertical. The method makes use of an approximate fundamental solution for displacements caused by a dynamic point load in a layered visco-elastic medium. The approximation involves a discretization of the medium in the vertical direction. In horizontal directions the medium is treated by continuum theory. The soil medium supports each pile at about 10 to 20 nodes. A dynamic flexiblity matrix for the soil is derived which relates the elastic, damping and inertial forces of the soil to the displacements at each node. It includes effects of radiation damping. All piles are coupled through the soil flexibility matrix. The piles are modelled by beam elements. Transient response is computed using fast discrete Fourier transforms. The arrangement of the piles is arbitrary. However, simple and double symmetry can be accounted for by the computer program. When the pile arrangement is axisymmetric, the degrees of freedom can be reduced to only those of two piles per ring. The influence of the number of piles and the influence of the pile spacing on group stiffness and on pile forces is presented for two soil profiles. Dynamic effects on pile forces of a foundation for a reactor building are studied. They are significant when soils are soft. (orig.)

A comparative study of soil-structure interaction in the case of frame structures with raft foundation

Directory of Open Access Journals (Sweden)

Móczár Balázs

2016-06-01

Full Text Available Design and modelling of raft foundations and selecting the value of coefficient of vertical subgrade reaction are still actively discussed topics in geotechnical and structural engineering. In everyday practice, soil–structure interaction is mostly taken into account by using the theory of ‘beam on elastic foundation’, in which the soil is substituted by a certain set of coefficients of subgrade reaction. In this study, finite element analysis of a building was performed using a geotechnical software (Plaxis 3D, which is capable of modelling the subsoil as a continuum, and a structural software (Axis VM, which uses the concept of ‘beam on elastic foundation’. The evaluation of the results and recommendations for everyday engineering practice are introduced in this paper.

Method of calculating pilestrip foundations in case of karst hole formation

Directory of Open Access Journals (Sweden)

Gotman Al'fred Leonidovich

2014-02-01

Full Text Available The paper presents pile strip foundations in the areas with karst risk. The analysis of karst hole formation mechanism shows the lateral soil pressure on the piles caused by the downfallen soil on the hole rims, which transfers around the hole edges during karst hole formation. In this case, the horizontal pressure of the pile reactive force in the area of the pile connection with the raft is transferred to the raft. Pile failure at the hole boundaries will lead to the increase of the raft bearing distance above the karst hole. The inadequate raft bearing capacity can provoke the emergency situation. The existing Codes on karst protective foundations design do not contain the analysis of pile and raft horizontal pressure under the downfallen soil.The goal of this work is to develop the method of pile strip foundations analysis in the areas with karst risk in case of karst hole formation. The analysis of stress-strain state of the system “foundation soil — pile foundation” was carried out using numerical modeling in geotechnical program MIDAS GTS. As a result of numerical investigations, the diagrams of lateral soil pressure onto the piles and the raft are plotted. The pile pressure is approximated with the linear or bilinear function in dependence on geometrical dimensions of the karst hole and strength characteristics of soil that generates the horizontal pressure.In the Codes, the analysis of a pile under lateral soil pressure is given for a pile with the free end. In the problem examined, the pile head has the hinged bearing in place of the connection with the raft. In view of the given boundary data, the pile design scheme is plotted. The inner forces and displacements of the pile are determined by integrating the differential equation of a pile bending. The consistent integrations are evaluated out of the boundary conditions. The boundary values of inner forces and displacements are evaluated from the equality conditions of

Observed variations of monopile foundation stiffness

DEFF Research Database (Denmark)

Kallehave, Dan; Thilsted, C.L.; Diaz, Alberto Troya

2015-01-01

full-scale measurements obtained from one offshore wind turbine structure located within Horns Reef II offshore wind farm. Data are presented for a 2.5 years period and covers normal operating conditions and one larger storm event. A reduction of the pile-soil stiffness was observed during the storm...... events, followed by a complete regain to a pre-storm level when the storm subsided. In additional, no long term variations of the pile-soil stiffness was observed. The wind turbine is located in dense to very dense sand deposits.......The soil-structure stiffness of monopile foundations for offshore wind turbines has a high impact on the fatigue loading during normal operating conditions. Thus, a robust design must consider the evolution of pile-soil stiffness over the lifetime of the wind farm. This paper present and discuss...

Soil-structure interaction analysis of NPP containments: substructure and frequency domain methods

International Nuclear Information System (INIS)

Venancio-Filho, F.; Almeida, M.C.F.; Ferreira, W.G.; De Barros, F.C.P.

1997-01-01

Substructure and frequency domain methods for soil-structure interaction are addressed in this paper. After a brief description of mathematical models for the soil and of excitation, the equations for dynamic soil-structure interaction are developed for a rigid surface foundation and for an embedded foundation. The equations for the frequency domain analysis of MDOF systems are provided. An example of soil-structure interaction analysis with frequency-dependent soil properties is given and examples of identification of foundation impedance functions and soil properties are presented. (orig.)

State-of-the-Art-Review of Collapsible Soils

Directory of Open Access Journals (Sweden)

A. A. AL-Rawas

2000-12-01

Full Text Available Collapsible soils are encountered in arid and semi-arid regions. Such soils cause potential construction problems due to their collapse upon wetting. The collapse phenomenon is primarily related to the open structure of the soil. Several soil collapse classifications based on parameters such as moisture content, dry density, Atterberg limits and clay content have been proposed in the literature as indicators of the soil collapse potential. Direct measurement of the magnitude of collapse, using laboratory and/or field tests, is essential once a soil showed indications of collapse potential. Treatment methods such as soil replacement, compaction control and chemical stabilization showed significant reduction in the settlement of collapsible soils. The design of foundations on collapsible soils depends on the depth of the soil, magnitude of collapse and economics of the design. Strip foundations are commonly used when collapsing soil extends to a shallow depth while piles and drilled piers are recommended in cases where the soil extends to several meters. This paper provides a comprehensive review of collapsible soils. These include the different types of collapsible soils, mechanisms of collapse, identification and classification methods, laboratory and field testing, treatment methods and guidelines for foundation design.

Influence of fabric anisotropy on seismic responses of foundations

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Jin Qin

2015-04-01

Full Text Available Earthquakes, as one of the well-known natural disasters, are highly destructive and unpredictable. Foundation failure due to liquefaction induced by earthquakes can cause casualties as well as significant damage to the building itself. Fabric anisotropy of soil grains is considered to be an important factor in dynamic soil response based on previous researches and laboratory tests. However, the limited availability of real physical data makes it less persuasive. In this study, a shake table installed on a geotechnical centrifuge is used to provide the designed seismic motions, and therefore, to simulate the realistic earthquake motion to foundations. Important parameters in the responses such as acceleration, excess pore pressure and deformation are evaluated to investigate the influence. Implications for design are also discussed.

Finite element analysis of skirted foundation adjacent to sand slope under earthquake loading

OpenAIRE

Azzam, W.R.

2015-01-01

This paper reports the application of using a skirted foundation system to study the behavior of foundations with structural skirts adjacent to a sand slope and subjected to earthquake loading. The effect of the adopted skirts to safeguard foundation and slope from collapse is studied. The skirts effect on controlling horizontal soil movement and decreasing pore water pressure beneath foundations and beside the slopes during earthquake is investigated. This technique is investigated numerical...

Interaction of the Bored Sand and Gravel Drain Pile with the Surrounding Compacted Loam Soil and Foundation Raft Taking into Account Rheological Properties of the Loam Soil and Non-Linear Properties of the Drain Pile

Science.gov (United States)

Ter-Martirosyan, Z. G.; Ter-Martirosyan, A. Z.; Anzhelo, G. O.; Buslov, A. S.

2018-01-01

The task of the interaction of the sand and gravel drain pile with the surrounding loam soil after its preliminary deep compaction and formation of the composite ground cylinder from the drain pile and surrounding compacted loam soil (cells) is considered in the article. It is seen that the subsidence and carrying capacity of such cell considerably depends on physical and mechanical properties of the compacted drain piles and surrounding loam soil as well as their diameter and intercellular distance. The strain-stress state of the cell is considered not taking into account its component elements, but taking into account linear and elastic-plastic properties of the drain pile and creep flow of the surrounding loam soil. It is stated that depending on these properties the distribution and redistribution of the load on a cell takes place from the foundation raft between the drain pile and surrounding soil. Based on the results of task solving the formulas and charts are given demonstrating the ratio of the load between the drain pile and surrounding loam soil in time.

Soil-structure interaction - a general method to calculate soil impedance

International Nuclear Information System (INIS)

Farvacque, M.; Gantenbein, F.

1983-01-01

A correct analysis of the seismic response of nuclear power plant buildings needs to take into account the soil structure interaction. The most classical and simple method consists in characterizing the soil by a stiffness and a damping function for each component of the translation and rotation of the foundation. In a more exact way an impedance function of the frequency may be introduced. Literature provides data to estimate these coefficients for simple soil and foundation configurations and using linear hypothesis. This paper presents a general method to calculate soil impedances which is based on the computation of the impulsive response of the soil using an axisymmetric 2D finite element Code (INCA). The Fourier transform of this response is made in the time interval before the return of the reflected waves on the boundaries of the F.E. domain. This procedure which limits the perturbing effects of the reflections is improved by introducing absorbing boundary elements. A parametric study for homogeneous and layered soils has been carried out using this method. (orig.)

Shallow foundation model tests in Europe

Czech Academy of Sciences Publication Activity Database

Feda, Jaroslav; Simonini, P.; Arslan, U.; Georgiodis, M.; Laue, J.; Pinto, I.

1999-01-01

Roč. 2, č. 4 (1999), s. 447-475 ISSN 1436-6517. [Int. Conf. on Soil - Structure Interaction in Urban Civ. Engineering. Darmstadt, 08.10.1999-09.10.1999] R&D Projects: GA MŠk OC C7.10 Keywords : shallow foundations * model tests * sandy subsoil * bearing capacity * settlement Subject RIV: JM - Building Engineering

Soil Fatigue Due To Cyclically Loaded Foundations

OpenAIRE

Pytlik, Robert Stanislaw

2016-01-01

Cyclic loading on civil structures can lead to a reduction of strength of the used materials. A literature study showed that, in contrast to steel structures and material engineering, there are no design codes or standards for fatigue of foundations and the surrounding ground masses in terms of shear strength reduction. Scientific efforts to study the fatigue behaviour of geomaterials are mainly focused on strain accumulation, while the reduction of shear strength of geomaterials has not been...

Implementation of a new Foundations Concept for Offshore Wind Farms

DEFF Research Database (Denmark)

Ibsen, Lars Bo

2008-01-01

The foundation principles for the recent major offshore wind farm projects in Europe have been dominated by two types of foundation solutions, the gravitational foundation and the monopile. A fully operational 3.0 MW offshore wind turbine was installed on a prototype of the bucket foundation...... at the test field in Frederikshavn in December 2002. A five-year research and development project has proven the bucket foundation to be feasible in suitable soil conditions in water depth from near shore to approximately 40 meters. The bucket foundation design reduces the steel weight by half compared...... with a traditional monopile solution and the installation of the bucket foundation is much easier and does not require heavy installation equipment. In this paper the full-scale field installation of the prototype is described. A design procedure has been developed in cooperation with the certifying party in order...

Soil mixing design methods and construction techniques for use in high organic soils : [summary].

Science.gov (United States)

2015-10-01

The soils which serve as foundations for construction projects may be roughly classified as : inorganic or organic. Inorganic soils vary in firmness and suitability for construction. Soft : or loose inorganic soils may be stabilized using cement or s...

Calculation of foundation response to spatially varying ground motion by finite element method

International Nuclear Information System (INIS)

Wang, F.; Gantenbein, F.

1995-01-01

This paper presents a general method to compute the response of a rigid foundation of arbitrary shape resting on a homogeneous or multilayered elastic soil when subjected to a spatially varying ground motion. The foundation response is calculated from the free-field ground motion and the contact tractions between the foundation and the soil. The spatial variation of ground motion in this study is introduced by a coherence function and the contact tractions are obtained numerically using the Finite Element Method in the process of calculating the dynamic compliance of the foundation. Applications of this method to a massless rigid disc supported on an elastic half space and to that founded on an elastic medium consisting of a layer of constant thickness supported on an elastic half space are described. The numerical results obtained are in very good agreement with analytical solutions published in the literature. (authors). 5 refs., 8 figs

Kinematic Interaction and Rocking Effects on the Seismic Response of Viaducts on Pile Foundations

International Nuclear Information System (INIS)

Dezi, F.; Carbonari, S.; Leoni, G.

2008-01-01

This paper is aimed at providing a contribution for a more accurate and effective design of bridges founded on piles. A numerical model is employed herein to determine the stresses and displacements in the piles taking into account soil-foundation-structure interaction. A 3D finite element approach is developed for piles and superstructure whereas the soil is assumed to be a Winkler-type medium. The method is applied to single piers representative for a class of bridges. Varying the soil layers characteristics and the pile spacing (from 3 to 5 diameters), bending and axial stresses along piles as well as the pier base shear are computed. A comparison with respect to a fixed-base model is provided. Special issues such as the contribution of the soil profile, of the local amplification and of the rocking at the foundation level are discussed. Soil-structure interaction is found to be essential for effective design of bridges especially for squat piers and soft soil

3-D seismic response analysis of liquid-tank-foundation system by using BEM-FEM-impedance function combination

International Nuclear Information System (INIS)

Cho, Eu-Kyeong; Park, Jung-Il; Lee, Jong-Rim

1995-01-01

A new analytic scheme to resolve the liquid-soil-structure interaction problem in cylindrical liquid storage tanks on the deformable soil is presented. Boundary elements and finite elements are combined to simulate the liquid-structure coupling effect while tuned foundation impedance functions (TFIF's) are representing the motion of the rigid foundation block on the flexible soil. Because the coupled dynamic system is expressed explicitly in terms of mass and stiffness, the developed scheme is applicable to any standard dynamic analysis methodologies. (author)

ISRIC - World Soil Information

NARCIS (Netherlands)

Dent, D.L.

2006-01-01

ISRICWorld Soil Information is an independent foundation, funded by the Netherlands Government with a mandate to increase knowledge of the land, its soils in particular, and to support the sustainable use of land resources; in short, to help people understand soils. Its aims are to -Inform and

Students Dig Deep in the Mystery Soil Lab: A Playful, Inquiry-Based Soil Laboratory Project

Science.gov (United States)

Thiet, Rachel K.

2014-01-01

The Mystery Soil Lab, a playful, inquiry-based laboratory project, is designed to develop students' skills of inquiry, soil analysis, and synthesis of foundational concepts in soil science and soil ecology. Student groups are given the charge to explore and identify a "Mystery Soil" collected from a unique landscape within a 10-mile…

Foundation heat transfer analysis for buildings with thermal piles

International Nuclear Information System (INIS)

Almanza Huerta, Luis Enrique; Krarti, Moncef

2015-01-01

Highlights: • A numerical transient thermal model for thermo-active foundations is developed. • Thermal interactions between thermal piles and building foundations are evaluated. • A simplified analysis method of thermal interactions between thermal piles and building foundations is developed. - Abstract: Thermal piles or thermo-active foundations utilize heat exchangers embedded within foundation footings to heat and/or cool buildings. In this paper, the impact of thermal piles on building foundation heat transfer is investigated. In particular, a simplified analysis method is developed to estimate the annual ground-coupled foundation heat transfer when buildings are equipped with thermal piles. First, a numerical analysis of the thermal performance of thermo-active building foundations is developed and used to assess the interactions between thermal piles and slab-on-grade building foundations. The impact of various design parameters and operating conditions is evaluated including foundation pile depth, building slab width, foundation insulation configuration, and soil thermal properties. Based on the results of a series of parametric analyses, a simplified analysis method is presented to assess the impact of the thermal piles on the annual heat fluxes toward or from the building foundations. A comparative evaluation of the predictions of the simplified analysis method and those obtained from the detailed numerical analysis indicated good agreement with prediction accuracy lower than 5%. Moreover, it is found that thermal piles can affect annual building foundation heat loss/gain by up to 30% depending on foundation size and insulation level

Use of an acoustic camera to define the stratigraphy of non-cohesive soils in the foundation of the Peribonka dam; Definition de la stratigraphie des sols pulverulents dans la fondation du barrage Peribonka au moyen d'une camera acoustique

Energy Technology Data Exchange (ETDEWEB)

Bouchard, R.; Babin, D. [Techmat Inc., Jonquiere, PQ (Canada); Turgeon, B. [Hydro-Quebec, Montreal, PQ (Canada)

2006-07-01

Hydro-Quebec's future Peribonka project is currently under construction 200 km north of the town of Saguenay, Quebec This document described the foundation conditions and presented a typical cross section of retaining works and foundation treatment methods. The foundation lies on an alluvial deposit. Due to the non-cohesive nature of the soil, studies were conducted to determine whether the technique of vibrocompaction could be used to prepare the foundation. Since conventional drilling techniques were not sufficient for this purpose, Techmat Inc. developed a unique method of using a digital acoustic televiewer for investigative purposes. The acoustic camera measured the amplitude and travel time of a rotating ultrasonic beam which was transmitted through the water and reflected against the borehole walls. Due to possible borehole wall collapse and sand infiltration, specialized tools to protect the televiewer were developed. These surveys were complementary to conventional drilling operations and provided acoustic images of the soil composition between sampled sections, to allow geotechnical engineers to better understand and visualize the underlying stratigraphy. The acoustic survey confirmed that vibrocompaction technique could be used. It was concluded that this acoustic viewing method could be used in the future when numerous obstacles complicate the identification of foundation soils and where conventional methods are inadequate. 5 refs., 5 figs.

Evaluation of Dynamic Behavior of Pile Foundations for Interim Storage Facilities Through Geotechnical Centrifuge Tests

International Nuclear Information System (INIS)

Shizuo Tsurumaki; Hiroyuki Watanabe; Akira Tateishi; Kenichi Horikoshi; Shunichi Suzuki

2002-01-01

In Japan, there is a possibility that interim storage facilities for recycled nuclear fuel resources may be constructed on quaternary layers, rather than on hard rock. In such a case, the storage facilities need to be supported by pile foundations or spread foundations to meet the required safety level. The authors have conducted a series of experimental studies on the dynamic behavior of storage facilities supported by pile foundations. A centrifuge modeling technique was used to satisfy the required similitude between the reduced size model and the prototype. The centrifuge allows a high confining stress level equivalent to prototype deep soils to be generated (which is considered necessary for examining complex pile-soil interactions) as the soil strength and the deformation are highly dependent on the confining stress. The soil conditions were set at as experimental variables, and the results are compared. Since 2000, the Nuclear Power Engineering Corporation (NUPEC) has been conducting these research tests under the auspices on the Ministry of Economy, Trade and Industry of Japan. (authors)

Soil/Structure Interactions in Earthquakes

Science.gov (United States)

Ramey, G. W.; Moore, R. K.; Yoo, C. H.; Bush, Thomas D., Jr.; Stallings, J. M.

1986-01-01

In effort to improve design of Earthquake-resistant structures, mathematical study undertaken to simulate interactions among soil, foundation, and superstructure during various kinds of vibrational excitation. System modeled as three lumped masses connected vertically by springs, with lowest mass connected to horizontal vibrator (representing ground) through springs and dashpot. Behavior of springs described by elastic or elastoplastic force/deformation relationships. Relationships used to approximate nonlinear system behavior and soil/foundation-interface behavior.

Dynamic analysis of the 7-GeV APS experiment hall foundation based on equivalent lumped parameter modeling

International Nuclear Information System (INIS)

Wambsganss, M.W.

1989-01-01

In this technical note, mass-spring-dashpot, also referred to as equivalent lumped parameter, models are employed to model the soil-foundation interaction of two typical floor segments from the 7-GeV APS experiment hall. Equivalent lumped parameter models have the advantage of being easy to apply and of readily allowing for parameter studies. Analysis requires knowledge of certain properties of the soil including density, shear wave velocity, and Poisson's ratio, as well as knowledge of the degree of homogeneity of the underlying soil stratum. These data for the APS site were determined by a geotechnical investigation. A soil profile and pertinent data, obtained from crosshole seismic testing, are given. Natural frequencies and damping are calculated for the vertical, sliding, rocking, and coupled rocking/sliding modes of vibration. Subsequently, various corrections to account for modeling ''deficiencies'' are considered and their influences evaluated. The equivalent lumped parameter models were developed for machine foundations which, compared with the APS foundation, are smaller in plan dimension. Therefore, the applicability of these models in the analysis of the dynamic characteristics of the APS foundation must be established. The modeling is evaluated by applying the equivalent lumped parameter models in the analysis of large foundations for which test data exists. A comparison of theoretical and test results establishes the basis for an assessment of the applicability and accuracy of the modeling

Earthquakes - dynamic loads on the foundation piles of a nuclear reactor

International Nuclear Information System (INIS)

Henning, F.; Dufour, C.; Fuzier, J.P.; Cheyrezy, M.

1976-01-01

The purpose of this paper is to analyse the behaviour of a piled foundation of a nuclear power plant submitted to earthquake loadings. The actual horizontal stiffness of the compound 'soil + structure' is calculated from the stiffness of the piles and the dynamic characteristics of the different layers of soil. The maximum amplitude of the horizontal displacement of the raft foundation is obtained by an iterative calculation from the displacement spectrum applied to the surrounding earth. At this stage, the moment diagrams for the different types of piles and their required reinforcement are calculated. The response of the nuclear plant components is determined from the displacement spectrum previously obtained for the raft. (author)

Interaction between Seabed Soil and Offshore Wind Turbine Foundations

DEFF Research Database (Denmark)

Hansen, Nilas Mandrup

velocity given by Darcy’s law (Sumer and Fredsøe, 2002, chap. 10). The constitutive equation for the soil considered in the model is the familiar stress-strain relationship for linear poro-elastic soils. The so-called no-slip boundary condition is adopted on the surface of the rocking pile. The numerical...

Physical Modelling of Bucket Foundations Subjected to Axial Loading

DEFF Research Database (Denmark)

Vaitkunaite, Evelina

Compared to oil and gas structures, marine renewable energy devices are usually much lighter, operate in shallower waters and are subjected to severe cyclic loading and dynamic excitations. These factors result in different structural behaviours. Bucket foundations are a potentially cost......-effective solution for various offshore structures, and not least marine renewables. The present thesis focuses on several critical design problems related to the behaviour of bucket foundations exposed to tensile loading. Among those are the soil-structure interface parameters, tensile loading under various...

Effects of inserted depth of wall penetration on basal stability of foundation pits

Science.gov (United States)

Zhou, Aizhao; Shen, Hao; Sun, Jinguo

2017-05-01

Evaluation of basal heave stability is one of important design checks for excavations in soft clays. The commonly used classical calculation method based on limit equilibrium theory and the safety coefficient formula recommended by the current code, do not consider the influence of supporting structure of foundation pit depth heave stability, which results in conservative. Considering the wall stiffness and strength, the effective stress changes in different depth of soil, the frictional resistance between the retaining wall and the passive zone, the vertical shear resistance of the soil behind the wall and other factors. The modified safety factor calculation formula of foundation pit stability is presented, comparison analysis of calculation method combined with examples. The calculation results show that the safety factor of foundation pit stability is improved considering the influence of supporting structure depth, the calculation results are more reasonable.

Foundations for low cost buildings

Directory of Open Access Journals (Sweden)

Sayed Abdel Salam

2017-04-01

Full Text Available Attaining an economical and safe design of structures is regarded as a prerequisite for the structural engineer. The market prices of reinforcing steels have dramatically soared in recent years internationally. Therefore, the purpose of the current paper is not just reducing the ratio of reinforcing steel in the foundations for skeleton structures, but rather minimizing this ratio through choosing the most effective footing shape (folded strip footings. Folded footings have been used as an alternative to the conventional rectangular strip footings. The height of the studied model is ten floors. Two different foundation systems are used in the analysis namely; rectangular strip footings, and folded strip footings respectively. Both footing shapes will be designed as continuous footings with grid shape under the building. Comparison between the two systems is also presented regarding the concrete sections and reinforcement ratio under the same applied loads. The finite element analysis software ADINA is used in modeling and analysis of the structural and geotechnical behavior of both types of footings, with emphasis on the effect of changing the footing shape on the stresses in the footing concrete body and the underlying soils. Research results presents the internal stresses within the footing and soil domains, as well as the contact pressure distribution for a reinforced folded strip footing resting on different soil types. The influence of folding inclination angle, and soil type on the results are also studied. Results showed that folded strip footings are efficient in reducing the amount of needed reinforcements, and such efficiency in reducing the required steel reinforcement in the footings is depending on the applied footing loads, and to some degree on the soil type and properties. Reduction in the reinforcement ratio between the rectangular and folded footing types is about 26% in favor of the folded strip footings. A comparative

CALCULATION OF FOUNDATIONS WITH CIRCULAR (CLOSED IN-PLANE SHAPES

Directory of Open Access Journals (Sweden)

L. S. Khasenevich

2017-01-01

Full Text Available It has been found that four reinforced concrete flue stacks being constructed in late 80-ies and early in 90-ies of the 20th century and being operated at various thermal power stations show practically no settlement, and this fact is not taken into account by any applicable regulatory documents. Foundations of these stacks were designed at the same time and they have been protected by patents of Russian Federation and Republic of Belarus. They represent circular bases made of reinforced concrete piles buried tightly together and forming so-called “slurry wall” with common monolithic reinforced concrete grillage. The grillage presents a direct extension of the stack shaft. One of these stacks has been built in Russia, and three – in Belarus. Due to significant differences in soil conditions and loads in each case, it is a fair assumption to say about regularity of the observed phenomenon. Notwithstanding the fact that circular foundations significantly decrease steel and concrete consumption, construction period and labour input, they have not yet received adequate attention from the side of scientific community and designers. While considering specific examples of the constructed stacks the paper reveals an opportunity to apply calculations which efficiently use passive soil resistance. The presented calculations and designs of the existing foundations make it possible to assess probability of the proposed methodology for the foundations which are analogous in design and which have closed in-plane structure not only for industrial buildings and structures.

Development of a macro-element by condensation, shown for the load categories of aircraft crash and seismic events, for soil-structure interaction in the case of flexible foundation

International Nuclear Information System (INIS)

Matthees, W.

1989-01-01

This report presents the results of a three-dimensional model developed for the analysis of soil-structure interaction problems. The realistic treatment of the stiffness for the foundation plate avoids the restriction of lumped parameter models for one-dimensional beam-models with a rigid plate or for multi-dimensional models with distributed lumped parameters. The soil-behaviour is defined by the condensation of a limited soil section, called macro-element. An improved matrix radiation damping comparable with lumped parameters is resultant from the condensation of viscous dampers, situated along the boundaries of the soil section. The finess of discretization is similar for the soil and for the structure. The method is presented in the time domain for a linear axisymmetric code with lumped mass having a consistent mass coupling of the macro-element. By application of the macro-element a realistic three-dimensional system may be analyzed with a reasonable numerical effort. (orig.) With 80 figs., 3 tabs [de

Behaviour of Cohesionless Soils During Cyclic Loading

DEFF Research Database (Denmark)

Shajarati, Amir; Sørensen, Kris Wessel; Nielsen, Søren Kjær

Offshore wind turbine foundations are typically subjected to cyclic loading from both wind and waves, which can lead to unacceptable deformations in the soil. However, no generally accepted standardised method is currently available, when accounting for cyclic loading during the design of offshore...... wind turbine foundations. Therefore a literature study is performed in order to investigate existing research treating the behaviour of cohesionless soils, when subjected to cyclic loading. The behaviour of a soil subjected to cyclic loading is found to be dependent on; the relative density, mean...

Seismic analysis of the pile foundation of the reactor building of the NPP ANGRA 2

International Nuclear Information System (INIS)

Wolf, J.P.; Arx, G.A. von; Barros, F.C.P. de; Kakubo, M.

1981-01-01

A pile foundation subjected to dynamic loads interacts with the surrounding soil. Frequency-dependent stiffness and radiation damping must be properly taken into account in pile-soil-pile interaction. Assuming that the soil consists of horizontal layers of elastic material with hysteretic damping, the dynamic stiffness of a group of (even battered) piles can be determined, accounting rigorously for the cavities where the soil is subsequently replaced by the piles. By way of illustration, this substructure procedure, which works in the frequency domain, is applied to the final design of the pile foundation of the Reactor Building of Angra 2 in Brazil. Below the basemat, a strongly horizontally-layered compressive soil of 36 m thickness rests on bedrock. The reactor building is founded on 202 endbearing piles and 88 floating piles of 15 m length. Every pile is modelled. Along each pile, compatibility between the pile and the soil in all three directions is formulated in seven nodes. The basemat is assumed to be rigid. On the level of bedrock a broad-banded response spectrum specifies the excitation (outcropping). (orig./WL)

Particularities of flat foundations for offshore wind power plants; Besonderheiten bei Flachgruendungen fuer Offshore-Windenergieanlagen

Energy Technology Data Exchange (ETDEWEB)

Miehe, Alina; Hartwig, Udo [Ed. Zueblin AG, Stuttgart (Germany). Technologiezentrum Erneuerbare Energien, Zentrale Technik

2012-07-01

Interest in offshore wind energy installations has increased significantly in Germany and globally. In Germany only foundation structures secured by piles are currently being constructed. However, a gravity foundation has major advantages in particular because of the self-restoring effect. In this contribution the soil mechanical behaviour of a gravity foundation is described and the currently valid standards and regulations for the dimensioning of the foundation listed. It is clear that regulations for gravity foundations in particular still require development. With regard to the test foundation, which has already been described in detail in previous publications, there follows a brief description of the laboratory programme and a short summary of the latest test foundation results. (orig.)

Model test on interaction of reactor building and soil. Part 1

International Nuclear Information System (INIS)

Iguchi, M.; Akino, K.; Kiva, Y.

1989-01-01

Theoretical and experimental studies on the effects of dynamic interaction between structures and soil have been carried out in recent years. Most of the dynamic tests, however, have been conducted using comparatively small-scale models. In order to evaluate the effects of soil-structure interaction for rigid structure such as reactor building, a series of tests, including forced vibration test and earthquake observations, was carried out. Large-scale models constructed on an actual soil were used. These tests included forced vibration tests on individual foundations, on foundations with superstructures, on cross interaction through the soil between adjacent structures. Tests on the embedded effects of foundation, on artificial ground-shaking, on large amplitude excitation, and aging effects in soil properties were performed. This paper describes the results of forced vibration tests and analyses of cross interaction through the soil between adjacent structures

Applications of the observational method in deep foundations

Directory of Open Access Journals (Sweden)

Fathi M. Abdrabbo

2012-12-01

Full Text Available The observational method was introduced into geotechnical engineering to improve both theories and construction techniques. This method was developed to avoid highly conservative assumptions about soil properties in geotechnical design when faced with unavoidable uncertainties of natural ground conditions. The assumptions involved in soil mechanics theories usually differ to a certain extent from reality. These assumptions can be improved by employing an observational database. Thus, theories of geotechnical engineering can be developed by observations during the construction stage. Moreover, precise management of construction work by close observations is essential to avoid risk and to alter the design if needed to match the real conditions. This paper sheds some light on the importance of the observational concept in deep foundations through three case studies. The first one demonstrates the effect of working hypotheses on design outputs of an open caisson of 22 m internal diameter. The other two case studies present the difference between theory and reality during construction stage of auger cast-in-place piles (ACIP in difficult subsoil conditions. Importance of merging the documented theories with the available observations is discussed. The study shows that working hypotheses and engineering models affect the cost and the time required for construction of deep foundations. Field observations are essential during installation of ACIP at a site. Some precautions should be considered when drilling ACIP through sandstone of inclined top surface. These precautions are mainly dependent upon field observations during construction. ACIP can be used effectively in soil formations that have galleries and caves using a cement–bentonite mixture to fill the holes of the unsuccessful piles. Finally, the paper shares a series of practical guidelines with engineering community all over the world that may assist in design and construction of deep

Development of soil taxation and soil classification as furthered by the Austrian Soil Science Society

Science.gov (United States)

Baumgarten, Andreas

2013-04-01

Soil taxation and soil classification are important drivers of soil science in Austria. However, the tasks are quite different: whereas soil taxation aims at the evaluation of the productivity potential of the soil, soil classification focusses on the natural development and - especially nowadays - on functionality of the soil. Since the foundation of the Austrian Soil Science Society (ASSS), representatives both directions of the description of the soil have been involved in the common actions of the society. In the first years it was a main target to improve and standardize field descriptions of the soil. Although both systems differ in the general layout, the experts should comply with identical approaches. According to this work, a lot of effort has been put into the standardization of the soil classification system, thus ensuring a common basis. The development, state of the art and further development of both classification and taxation systems initiated and carried out by the ASSS will be shown.

Seismic performance of an existing bridge with scoured caisson foundation

Science.gov (United States)

Chang, Kuo-Chun; Sung, Yu-Chi; Liu, Kuang-Yen; Wang, Ping-Hsiung; Lee, Zheng-Kuan; Lee, Lu-Sheng; Witarto

2014-08-01

This paper presents in-situ seismic performance tests of a bridge before its demolition due to accumulated scouring problem. The tests were conducted on three single columns and one caisson-type foundation. The three single columns were 1.8 m in diameter, reinforced by 30-D32 longitudinal reinforcements and laterally hooped by D16 reinforcements with spacing of 20 cm. The column height is 9.54 m, 10.59 m and 10.37 m for Column P2, P3, and P4, respectively. Column P2 had no exposed foundation and was subjected to pseudo-dynamic tests with peak ground acceleration of 0.32 g first, followed by one cyclic loading test. Column P3 was the benchmark specimen with exposed length of 1.2 m on its foundation. The exposed length for Column P4 was excavated to 4 m, approximately 1/3 of the foundation length, to study the effect of the scouring problem to the column performance. Both Column P3 and Column P4 were subjected to cyclic loading tests. Based on the test results, due to the large dimension of the caisson foundation and the well graded gravel soil type that provided large lateral resistance, the seismic performance among the three columns had only minor differences. Lateral push tests were also conducted on the caisson foundation at Column P5. The caisson was 12 m long and had circular cross-sections whose diameters were 5 m in the upper portion and 4 m in the lower portion. An analytical model to simulate the test results was developed in the OpenSees platform. The analytical model comprised nonlinear flexural elements as well as nonlinear soil springs. The analytical results closely followed the experimental test results. A parametric study to predict the behavior of the bridge column with different ground motions and different levels of scouring on the foundation are also discussed.

Consolidation Theory for a Stone Column Composite Foundation under Multistage Loading

OpenAIRE

Huang, Shenggen; Feng, Yingtao; Liu, Hao; Wu, Wenbing; Mei, Guoxiong

2016-01-01

The consolidation theories considering instant load cannot fully reveal the consolidation mechanism of a stone column composite foundation used in the expressway embankments due to the time effect of loading; that is, the expressway embankments are often constructed in several stages for a long time. Meanwhile, owing to the special property that the pile-soil stress ratio is larger than 1, the consolidation theory for sand drain well foundation cannot be used directly in the consolidation ana...

Transient Analysis of Monopile Foundations Partially Embedded in Liquefied Soil

DEFF Research Database (Denmark)

Barari, Amin; Bayat, Mehdi; Meysam, Saadati

2015-01-01

Lagrangian Analysis of Continua (FLAC), which captured the fundamental mechanisms of the monopiles in saturated granular soil. The effects of inertia and the kinematic flow of soil are investigated separately, to highlight the importance of considering the combined effect of these phenomena on the seismic...

Influence of foundation type and soil stratification on ground vibration - a parameter study

DEFF Research Database (Denmark)

Andersen, Lars Vabbersgaard; Prins, Joeri Nithan; Persson, Kent

2016-01-01

a significant influence. Thus, in order to achieve fair accuracy in the prediction of ground vibration caused by sources vibrating on a foundation, accurate models of the ground and foundation may be required. However, for assessment of vibration in the design phase, simple models may be preferred. The paper...

Empirical Design of Scour Protections around Monopile Foundations

DEFF Research Database (Denmark)

De Vos, L.; De Rouck, J.; Troch, P.

2011-01-01

in a current alone situation), at present, little design guidelines exist for the specific case of a scour protection around a monopile foundation subjected to a combined wave and current loading. This paper describes the derivation of a static design formula to calculate the required stone size for a scour......Together with new opportunities, offshore wind farms raise new engineering challenges. An important aspect relates to the erosion of bottom material around the foundation of the wind turbines, caused by the local increase of the wave and current induced flow velocities by the pile's presence....... Typically, the expected scour has a considerable impact on the stability and dynamic behavior of the wind turbine and a scour protection is placed to avoid erosion of the soil close to the foundation. Although much experience exists on the design of scour protections around bridge piers (which are placed...

Seismic response of a nonsymmetric nuclear reactor building with a flexible stepped foundation

International Nuclear Information System (INIS)

Okano, H.; Sakai, A.; Takita, H.; Fukunishi, S.; Nakatogawa, T.; Kabayama, K.

1993-01-01

The effect of the non symmetry of a nuclear reactor building on its seismic response was studied. The nonsymmetric natures we considered, Included the eccentricity of the superstructure and the non symmetry of the cross section of the foundation. A three-dimensional analysis which employed Green's function was applied to study the interaction between the soil and the non symmetrically sectioned foundation. The effect of a flexible foundation on its seismic response was also studied by applying the sub structuring method, which combines the finite element method and Green's function method. (author)

Excavationless Exterior Foundation Insulation Exploratory Study

Energy Technology Data Exchange (ETDEWEB)

Mosiman, G.; Wagner, R.; Schirber, T.

2013-02-01

The key objective of this exploratory study was to investigate the feasibility of the development or adoption of technologies that would enable a large percentage of existing homes in cold climates to apply a combination 'excavationless' soil removal process with appropriate insulation and water management on the exterior of existing foundations at a low cost. Our approach was to explore existing excavation and material technologies and systems to discover whether potential successful combinations existed.

Design Optimization of Piles for Offshore Wind Turbine Jacket Foundations

DEFF Research Database (Denmark)

Sandal, Kasper; Zania, Varvara

Numerical methods can optimize the pile design. The aim of this study is to automatically design optimal piles for offshore wind turbine jacket foundations (Figure 1). Pile mass is minimized with constraints on axial and lateral capacity. Results indicate that accurate knowledge about soil...

Analysis of foundation type alternative and deep-excavation on candidate site location of Panjang Island, Serang

International Nuclear Information System (INIS)

Heri Syaeful; June Mellawati

2013-01-01

Panjang Island is one of the alternatives location which is being studied as NPP site candidate. Its soil surface dominated by sand and eggshell deposit to the depth of tens of meter, beside that also the interlayer of sand and clay to the depth of 120 m. Purpose of the research is to analyze the alternative of foundation type and simulation of deep-excavation during foundation construction especially related to the slope stability aspect. The methods includes data collection of the analysis result of soil/rock mechanical laboratory, measurement of shear wave velocity by PS logging method, and analysis of alternative foundation type and deep-excavation. The analysis result of foundation type that can be applied on Panjang Island candidate site is combination of raft and pile foundation. Rock with Vs > 400 m/s in depth of 44 meter could be made as base of raft foundation construction. In the bottom it connected to pile foundation which is constructed to base rock in the depth of 120 m in Vs > 900 m/s. The result of slope stability analysis on deep-excavation with slope height of 44 m, vertical angle, on normal condition yield safety factor of 0,184 and on the condition of seismic load 0,138. Simulation of anchor installation with spacing 1.25 m as much as 15 pieces yield safety factor higher than 1.0 m. (author)

Load and resistance factor design of bridge foundations accounting for pile group-soil interaction.

Science.gov (United States)

2015-11-01

Pile group foundations are used in most foundation solutions for transportation structures. Rigorous and reliable pile design methods are : required to produce designs whose level of safety (probability of failure) is known. By utilizing recently dev...

Seismic soil structure interaction: analysis and centrifuge model studies

International Nuclear Information System (INIS)

Finn, W.D.L.; Ledbetter, R.H.; Beratan, L.L.

1985-01-01

A method for non-linear dynamic effective stress analysis is introduced which is applicable to soil-structure interaction problems. Full interaction including slip between structure and foundation is taken into account and the major factors are included which must be considered when computing dynamic soil response. An experimental investigation was conducted using simulated earthquake tests on centrifuged geotechnical models in order to obtain prototype response data of foundation soils carrying both surface and embedded structures and to validate the dynamic effective stress analysis. Horizontal and vertical accelerations were measured at various points on structures and in the sand foundation. Seismically-induced pore water pressure changes were also measured at various locations in the foundation. Computer plots of the data were obtained while the centrifuge was in flight and representative samples are presented. The results show clearly the pronounced effect that increasing pore water pressures have on dynamic response. It is demonstrated that a coherent picture of dynamic response of soil-structure systems is provided by dynamic effective stress non-linear analysis. Based on preliminary results, it appears that the pore water pressure effects can be predicted

Seismic soil-structure interaction: Analysis and centrifuge model studies

International Nuclear Information System (INIS)

Finn, W.D.L.; Ledbetter, R.H.; Beratan, L.L.

1986-01-01

A method for nonlinear dynamic effective stress analysis applicable to soil-structure interaction problems is introduced. Full interaction including slip between structure and foundation is taken into account and the major factors that must be considered when computing dynamic soil response are included. An experimental investigation using simulated earthquake tests on centrifuged geotechnical models was conducted to obtain prototype response data of foundation soils carrying both surface and embedded structures and to validate the dynamic effective stress analysis. The centrifuge tests were conducted in the Geotechnical Centrifuge at Cambridge University, England. Horizontal and vertical accelerations were measured at various points on structures and in the sand foundation. Seismically induced pore water pressure changes were also measured at various locations in the foundation. Computer plots of the data were obtained while the centrifuge was in flight and representative samples are presented. The results clearly show the pronounced effect of increasing pore water pressures on dynamic response. It is demonstrated that a coherent picture of dynamic response of soil-structure systems is provided by dynamic effective stress nonlinear analysis. On the basis of preliminary results, it appears that the effects of pore water pressure can be predicted. (orig.)

Validity of Simplified Analysis of Stability of Caison Breakwaters on Rubble Foundation Exposed to Impulsive Loads

DEFF Research Database (Denmark)

Andersen, Lars; Burcharth, Hans F.; Andersen, Thomas Lykke

Excessive sliding and foundation failures are common failure modes for caisson breakwaters on rubble foundations. An accurate evaluation of these failure modes demands a dynamic analysis in the time domain, and due to the complexity of the material response, numerical solution methods must be app...... be applied. The waveload time series as well as elastic-plastic modelling of the seabed soil, the rubble foundation and the caisson are needed as input for such an exercise....

CALCULATION OF FOUNDATIONS-COVERS FOR CONSTRUCTIONS OF TOWER TYPE ON THE IMPACT OF UNEVEN SUBSIDENCE OF BASE

Directory of Open Access Journals (Sweden)

TIMCHENKO R. A.

2015-10-01

Full Text Available Problem statement. Among the constructions of the tower type there are the foundations are made as round or circular plate and a truncated conical coverleans on it being a continuation of kernel hardness. The round in plan and circular annular reinforced concrete foundations are mainly used in engineering structures, such as chimneys, silos, water towers, tanks. Buildings and structures built on the unfavorable areas are exposed with deformation influence from the foundation. The degree of weakening of the foundation depends on the size of the horizontal deformations and change of the structure and state of the soil. Purpose. Reduced the characteristics of weak bases are defined differently, depending on the nature, type and size of deformation. Not for all cases, there are specific recommendations as for their definition. The work of round, circular, polygonal shape of the foundation plates is not studied enough in these conditions and requires consideration. Conclusion. One of the actual problems of the foundation structures design is to define the limits of deformation effects for a certain type of foundation for a given force loading in hard soil conditions. This task can be solved with a gradual increase of deformation impacts on foundation (increasing of curvature, slope, subsidence, dimensions of the ledge, the diameter of the failures. Foundation structures should be designed with such dimensions that the ratio of the stiffness of the plate and the foundation will be conformed to the highest capacity of plate, then supporting capacity of the elements of the system are used most fully.

Ultimate capacity of piles penetrating in weak soil layers

Directory of Open Access Journals (Sweden)

Al-Obaidi Ahmed

2018-01-01

Full Text Available A pile foundation is one of the most popular forms of deep foundations. They are routinely employed to transfer axial structure loads through the soft soil to stronger bearing strata. Piles generally used to increase the load carrying capacity of the foundation and reduce the settlement of the foundation. On the other hand, many cases in practice where piles pass through different layers of soil that contain weak layers located at different depths and extension, also some time cavities with a different shape, size, and depth are found. In this study, a total of 96 cases is considered and simulated in PLAXIS 2D program aiming to understand the influence of weak soil on the ultimate pile capacity. The piles embedded in the dense sand with a layer of weak soil at different extension and location. The cross section of the geometry used in this study was designed as an axisymmetric model with the 15-node element; the boundary condition recommended at least 5D in the horizontal direction, and (L+5D in the vertical direction where D and L are the diameter and length of pile, respectively. The soil is modeled as Mohr-Coulomb, with five input parameters and the behavior of pile material represented by the linear elastic model. The results of the above cases are compared with the results found in a pile embedded in dense soil without weak layers or cavities. The results indicated that the existence of weak soil layer within the surrounding soil around the pile decreases the ultimate capacity. Furthermore, it has been found that increase in the weak soil width (extension leads to reduction in the ultimate capacity of the pile. This phenomenon is applicable to all depth of weak soil. The influence of weak layer extension on the ultimate capacity is less when it is presentin the upper soil layers.

Effects of structural nonlinearity and foundation sliding on probabilistic response of a nuclear structure

International Nuclear Information System (INIS)

Hashemi, Alidad; Elkhoraibi, Tarek; Ostadan, Farhang

2015-01-01

Highlights: • Probabilistic SSI analysis including structural nonlinearity and sliding are shown. • Analysis is done for a soil and a rock site and probabilistic demands are obtained. • Structural drift ratios and In-structure response spectra are evaluated. • Structural nonlinearity significantly impacts local demands in the structure. • Sliding generally reduces seismic demands and can be accommodated in design. - Abstract: This paper examines the effects of structural nonlinearity and foundation sliding on the results of probabilistic structural analysis of a typical nuclear structure where structural nonlinearity, foundation sliding and soil-structure interaction (SSI) are explicitly included. The evaluation is carried out for a soil and a rock site at 10"4, 10"5, and 10"6 year return periods (1E − 4, 1E − 5, and 1E − 6 hazard levels, respectively). The input motions at each considered hazard level are deaggregated into low frequency (LF) and high frequency (HF) motions and a sample size of 30 is used for uncertainty propagation. The statistical distribution of structural responses including story drifts, and in-structure response spectra (ISRS) as well as foundation sliding displacements are examined. The probabilistic implementation of explicit structural nonlinearity and foundation sliding in combination with the SSI effects are demonstrated using nonlinear response history analysis (RHA) of the structure with the foundation motions obtained from elastic SSI analyses, which are applied as input to fixed-base inelastic analyses. This approach quantifies the expected structural nonlinearity and sliding for the particular structural configuration and provides a robust analytical basis for the estimation of the probabilistic distribution of selected demands parameters both at the design level and beyond design level seismic input. For the subject structure, the inclusion of foundation sliding in the analysis is found to have reduced both

Literature review on cyclic lateral loading effects of mono-bucket foundations

DEFF Research Database (Denmark)

Kapitanov, Lachezar Rosenov; Duroska, Peter; Quirante, Cesar Antonio Garcia

2016-01-01

and consequently cost-effectiveness compared to other common solutions. The long-term cyclic loading can cause degradation of soil-bucket system stiffness, which yields into accumulated and permanent deformations. Despite of the advantages, there is no standard procedure to design the foundation especially...... calculation is highly demanded at the different design phases. The intention of the current study is to present, review and summarize the existing techniques to assess the effect of cyclic loading on Mono-Bucket foundations while emphasizing the advantage and disadvantage of each of them. Additionally...

Site study plan for Exploratory shaft facilities design foundation boreholes (shaft surface facility foundation borings), Deaf Smith County Site, Texas: Surface-based geotechnical field program: Preliminary draft

International Nuclear Information System (INIS)

1987-12-01

This site study plan describes the Exploratory Shaft Facilities (ESF) Design Foundation Boreholes field activities to be conducted during early stages of Site Characterization at the Deaf Smith County, Texas, site. The field program has been designed to provide data useful in addressing information/data needs resulting from federal/state/local regulations, and repository program requirements. Approximately 50 foundation boreholes will be drilled within the ESP location to provide data necessary for design of the ESF and to satisfy applicable shaft permitting requirements. Soils and subsurface rock will be sampled as the foundation boreholes are advanced. Soil samples or rock core will be taken through the Blackwater Draw and Ogallala Formations and the Dockum Group. Hydrologic testing will be performed in boreholes that penetrates the water table. In-situ elastic properties will be determined from both the soil strata and rock units along the length of the boreholes. Field methods/tests are chosen that provide the best or only means of obtaining the required data. The Salt Repository Project (SRP) Networks specify the schedule under which the program will operate. Drilling will not begin until after site ground water baseline conditions have been established. The Technical Field Services Contractor is responsible for conducting the field program of drilling and testing. Samples and data will be handled and reported in accordance with established SRP procedures. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that the appropriate documentation is maintained. 25 refs., 10 figs., 6 tabs

Three-dimensional analysis for piled raft machine foundation embedded in sand

Directory of Open Access Journals (Sweden)

Mahmood Mahmood

2018-01-01

Full Text Available Three-dimensional analysis for the dynamic response of a piled raft foundation subjected to vertical vibration is presented in this study. The analysis considers several factors affecting the amplitude of displacement for deep foundation such as pile cap embedment, pile cap thickness, relative density of the sand and the boundary effect. A validation for an experimental piled raft model depending on a scale factor of (20 using at (Plaxis 3D computer program was performed. The sand is simulated using Mohr-Coloumb model while the concrete is simulated as linear elastic material. It has been found that embedding the pile cap in the soil and increasing its thickness lead to decrease the maximum amplitude of displacement. Furthermore, the predictions showed that increasing the distance between the foundation and the boundaries and increasing the relative density of the sand can significantly minimize the dynamic response of the foundation.

Application of advanced non-destructive testing to evaluate the foundation depth of the existing structures

International Nuclear Information System (INIS)

Nguyen Le Son; Nguyen Phuoc Lan; Pham The Hung; Vu Huy Thuc; Phan Chanh Vu; Bui Xuan Huy; Tran Thanh Luan; Nguyen Kien Chinh; Le Danh Chuan

2004-01-01

The applications of Parallel Seismic Test to evaluate deep foundations of the existing structures are still new in Vietnam. Under the framework of the basic VAEC project (2003) and project VIE/8/013, the parallel seismic test method (PSM) was evaluated at Center for Nuclear Techniques, Hochiminh City. Background information on principle and general description of the method as it is typically applied in the evaluation of deep foundations are also summarized. A suitable test site was selected, where the foundation depths can be controlled for the parallel seismic tests were conducted by impacting the driven piles, and the travel times down the pile, through the soil, to a receiver located in an adjacent water-filled borehole were measured. The primary objective of the test program is to evaluated the accuracy of method in determining the pile length, to evaluate the capabilities of the method and the equipped system SPL-97, to define the type of material which comprises a deep foundation, the distance of the compression wave can travel through the adjacent soil before the signal attenuates beyond recognition and the ware velocities in the various soil strata encountered. The parallel seismic testing program is described and results are presented. Parallel seismic tests, as conventionally practiced, i.e. with short distance between a structure and an access hole, can be used to define the bottom of the piles, as well as to identify the material type from the computed velocity in the structural material. The conventional approach of using changes of slop of the plot versus first arrival to identify the bottom of a deep foundation works best when the piles are in a soil with uniform stiffness and the accuracy of the evaluated depths can be obtained about ± 0.5 m. Supplementing this approach of interpretation by the examining the amplitudes of the first arrival on a plot with the same scale for all records allows one to better interpret signals in more common

Analyzing the effect of large rotations on the seismic response of structures subjected to foundation local uplift

Directory of Open Access Journals (Sweden)

El Abbas N.

2016-01-01

Full Text Available This work deals with seismic analysis of structures by taking into account soil-structure interaction where the structure is modeled by an equivalent flexible beam mounted on a rigid foundation that is supported by a Winkler like soil. The foundation is assumed to undergo local uplift and the rotations are considered to be large. The coupling of the system is represented by a series of springs and damping elements that are distributed over the entire width of the foundation. The non-linear equations of motion of the system were derived by taking into account the equilibrium of the coupled foundation-structure system where the structure was idealized as a single-degree-of-freedom. The seismic response of the structure was calculated under the occurrence of foundation uplift for both large and small rotations. The non-linear differential system of equations was integrated by using the Matlab command ode15s. The maximum response has been determined as function of the intensity of the earthquake, the slenderness of the structure and the damping ratio. It was found that considering local uplift with small rotations of foundation under seismic loading leads to unfavorable structural response in comparison with the case of large rotations.

Design, construction, and initial performance of wind turbine foundations in Antarctica

Energy Technology Data Exchange (ETDEWEB)

Oswell, J.M. [Naviq Consulting Inc., Calgary, AB (Canada); Mitchell, M.; Chalmers, G.; Mackinven, H. [Opus Internation Consultants Ltd., Christchurch (New Zealand)

2010-07-01

This article discussed the design and primary issues related to installing the foundations for 3 wind turbines established for generating electricity at research stations in Antarctica. The extreme frigidity of the climate, the unusual geotechnical subsoil conditions, and the technology constraints resulting from isolation had to be contended with in all aspects of the project, including site evaluation, design, construction, and monitoring. The foundation design required strict tolerance on differential settlement. The estimation of creep settlement over the entire life of the project was the most important aspect. The surface loads on the foundation were grouped by load duration to estimate the corresponding creep settlement. The tower foundations were proposed as multi-leg arrangement buried at a relatively shallow depth within the continuous permafrost. The creep behaviour of the soils, estimates of long-term settlement, and the development of contingency and mitigation measures for non-compliant foundation behaviour were necessary to meet the allowable differential settlement of the towers. The paper described the subsurface conditions, the foundation system, and the performance data taken after one thaw season. Continued monitoring will ensure that performance requirements are met. 6 refs., 3 tabs., 10 figs.

Effect of foundation embedment on the response of a multi-story building to earthquake excitation

Directory of Open Access Journals (Sweden)

Hamood Mohammed

2018-01-01

Full Text Available During an earthquake, the behaviour of any structure is affected not only by the superstructure response, but also by the response of the soil beneath. Recent structural failure patterns have indicated the significance of soil-structure interaction (SSI effects. The present study focuses on SSI analysis considering the embedment depth of the foundation of a symmetric six stories reinforced concrete (RCspace bare frame building resting on stiff soil and subjected to seismic loading. The finite element analysis software ANSYS v17.2 is used. Time history (TH analysis has been adopted. The Response in terms of lateral displacements, base shear forces, base moments and variation in natural time periods are calculated from the analysis of the soil foundation structure interaction (SFSI model. Results are compared with that obtained from conventional method assuming rigid support at the base (fixed base of the structure. The results show that the SFSI considering different embedment depths are significant in altering the seismic response of the multi-story building (MSB.

Numerical simulation of installation of skirt foundations

Energy Technology Data Exchange (ETDEWEB)

Vangelsten, Bjoern Vidar

1997-12-31

Skirt foundation has been increasingly used for permanent offshore oil installations and anchors for drilling ships. Suction is commonly used in skirt foundation installing. If a large amount of suction is applied, the soil around the foundation may fail and the foundation become useless. This thesis studies failure due to high seepage gradients, aiming to provide a basis for reducing the risk of such failures. Skirt penetration model testing has shown that to solve the problem one must understand what is going on at the skirt tip during suction installation. A numerical model based on micro mechanics was developed as continuum hypothesis was seen to be unsuitable to describe the processes in the critical phases of the failure. The numerical model combines two-dimensional elliptical particles with the finite difference method for flow to model water flow in a granular material. The key idea is to formulate the permeability as a function of the porosity of the grain assembly and so obtain an interaction between the finite difference method on flow and the particle movement. A computer program, DYNELL, was developed and used to simulate: (1) weight penetration of a skirt wall, (2) combined suction and weight penetration of a skirt wall, and (3) critical gradient tests around a skirt wall to study failure mechanisms. The model calculations agree well with laboratory experiments. 16 refs., 124 figs., 21 tabs.

Evaluation of stability of foundation ground during earthquake, 6

International Nuclear Information System (INIS)

Kanatani, Mamoru; Nishi, Koichi

1988-01-01

The aseismatic capability of nuclear power plants located on Quaternary grounds, which consist of dense sand or sandy gravel, is heavily dependent on the stability of foundation grounds during earthquakes. In order to investigate into the stability of ground more in detail, it is necessary to develop the nonlinear earthquake response analysis method which can simulate the inelastic behavior of soil. In this report, the newly developed nonlinear response analysis method based on the effective stress, the results of simulation using the results of vibration table test and centrifuge test, and the case studies on two-dimensional soil-structure interaction problems are described. Soil was regarded as the two-phase mixture composed of soil particle skeleton and pore water. In the equation of motion taking their interaction into account, the elastoplastic constitutive equation that can simulate the inelastic deformation behavior of soil at the time of repeated shearing in two or three-dimensional field was introduced, and the analysis code which successively traces the behavior of ground at the time of earthquakes using FEM was developed. (K.I.)

Dynamic Analysis of Wind Turbines Including Soil-Structure Interaction

DEFF Research Database (Denmark)

Harte, M.; Basu, B.; Nielsen, Søren R.K.

2012-01-01

This paper investigates the along-wind forced vibration response of an onshore wind turbine. The study includes the dynamic interaction effects between the foundation and the underlying soil, as softer soils can influence the dynamic response of wind turbines. A Multi-Degree-of-Freedom (MDOF......) horizontal axes onshore wind turbine model is developed for dynamic analysis using an Euler–Lagrangian approach. The model is comprised of a rotor blade system, a nacelle and a flexible tower connected to a foundation system using a substructuring approach. The rotor blade system consists of three rotating...... for displacement of the turbine system are obtained and the modal frequencies of the combined turbine-foundation system are estimated. Simulations are presented for the MDOF turbine structure subjected to wind loading for different soil stiffness conditions. Steady state and turbulent wind loading, developed using...

strength characterization of foundation soils at federal university ...

African Journals Online (AJOL)

HOD

used to calculate bearing capacity factors for structural footings [1]. One of in situ testing methods is the. Standard Penetration Test (SPT) that is used to identify soil type and stratigraphy along with being a relative measure of strength [2]. In this study, the SPT blow count was used as a parameter for in situ characterization of.

Seismic response of pile foundations and pile forces caused by kinematic and inertial interaction

International Nuclear Information System (INIS)

Hartmann, H.G.; Waas, G.

1985-01-01

The horizontal motion and pile forces of pile groups subjected to earthquake excitation are analysed. The piles are modelled as linear elastic beam elements embedded in a layered linear visco-elastic soil medium. Pile-soil-pile interaction is included. The earthquake excitation results from vertically propagating shear waves. Kinematic and inertial interaction effects on foundation motion and pile forces are studied for a single pile, a small pile group and a large pile group. Soft and stiff soil conditions are considered, and the effect of a flexible vs. a rigid halfspace below the soil layers is shown. (orig.)

Development of a socketed foundation for the Midwest Weak Post (MWP) v1.

Science.gov (United States)

2014-07-01

A socketed foundation was designed and evaluated for use with the Midwest Weak Post (MWP), Version 1. : Dynamic component testing was conducted on five different design configurations with varying embedment : depths, steel reinforcement, and soil con...

Investigation of block foundations resting on soil–rock and rock–rock media under coupled vibrations

Directory of Open Access Journals (Sweden)

Renuka Darshyamkar

2017-04-01

Full Text Available In the present study, the dynamic response of block foundations of different equivalent radius to mass (Ro/m ratios under coupled vibrations is investigated for various homogeneous and layered systems. The frequency-dependent stiffness and damping of foundation resting on homogeneous soils and rocks are determined using the half-space theory. The dynamic response characteristics of foundation resting on the layered system considering rock–rock combination are evaluated using finite element program with transmitting boundaries. Frequencies versus amplitude responses of block foundation are obtained for both translational and rotational motion. A new methodology is proposed for determination of dynamic response of block foundations resting on soil–rock and weathered rock–rock system in the form of equations and graphs. The variations of dimensionless natural frequency and dimensionless resonant amplitude with shear wave velocity ratio are investigated for different thicknesses of top soil/weathered rock layer. The dynamic behaviors of block foundations are also analyzed for different rock–rock systems by considering sandstone, shale and limestone underlain by basalt. The variations of stiffness, damping and amplitudes of block foundations with frequency are shown in this study for various rock–rock combinations. In the analysis, two resonant peaks are observed at two different frequencies for both translational and rotational motion. It is observed that the dimensionless resonant amplitudes decrease and natural frequencies increase with increase in shear wave velocity ratio. Finally, the parametric study is performed for block foundations with dimensions of 4 m × 3 m × 2 m and 8 m × 5 m × 2 m by using generalized graphs. The variations of natural frequency and peak displacement amplitude are also studied for different top layer thicknesses and eccentric moments.

An experimental study on advancement of damping performance of foundations in soft ground. Pt.2: Experiment focusing on damping and antivibration performance of side surface of foundation blocks

International Nuclear Information System (INIS)

Ishimaru, S.; Shimomura, Y.; Kawamuram, M.; Ikeda, Y.; Hata, I.; Miwa, S.

2005-01-01

To aim at progress of damping performance of foundations that will be built at soft ground, we have proposed an improved foundation work of backfilling a damping material into trenches dug along a foundation supported by improved soil medium. This damping material is a mixture of asphalt with crushed stones and rubber chips (MACSRC) and has itself high attenuation and mitigation performance. Not only to comprehend the attenuation ability of the improved foundation work quantitatively and qualitatively but also to verify the effectiveness of this work, we carried out forced vibration tests for two test blocks, which were constructed by a normal construction work and the above improved foundation work. According to the experiment results of the blocks by the normal construction work and by the improved foundation work that were excited by the vibration generator, magnitude of amplitudes of the latter became half than the former. Effectiveness in the attenuation performance of MACSRC was confirmed. When the block by the normal construction work was vibrated, the improved foundation work decreased magnitude of amplitude of the adjacent block than the normal construction work. It is expected that MACSRC would exert mitigation ability against earthquakes or other external and internal forces. (authors)

Effects of soil stiffness and embedment on reactor building response

International Nuclear Information System (INIS)

Michalopoulos, A.P.; Vardanega, C.; Cornaggia, L.

1981-01-01

A parametric study was made to assess the influence of soil conditions and foundation embedment depth on the floor response spectra for a reactor building. The analyses incorporated soft, medium and hard soils, and three different embedment depths, in a seismic environment described by a 0.36 g peak ground acceleration. The shear wave velocity profiles for the soft, medium and hard soil conditions, were assumed to increase in proportion to the square root of depth from their ground surface values of 300, 600 and 900 meters per second, respectively. Foundation embedment depths of zero, eight and fourteen meters were analyzed using elastic half-space theory, accounting for kinematic interaction. The variation of shear modulus with depth under earthquake excitation was determined using a deconvolution process. Horizontal and vertical synthetic time histories, matching the USNRC Regulatory Guide 1.60 design ground response spectra, were applied at the ground surface and then deconvolved to the foundation level to obtain the input for the soil-structure model. The mathematical model of the superstructure consisted of four lumped-mass close-coupled systems, representing containment shells and components, while the foundation mat was modeled as rigid. Lumped soil compliances (springs and dashpots) were used to represent the horizontal, vertical and rotational modes of vibration. The dynamic analyses were performed utilizing the computer code DAPSYS, and consisted of mode frequency analyses and modal superposition. Modal damping was computed as a weighted average of structural and soil (radiation and material) damping, using the strain energy stored in the respective components as the weighting factor and distinguishing the hysteric nature of the structural and soil material damping, and the viscous nature of the soil radiation damping. (orig./RW)

Investigation of pile foundations of nuclear power plants with help of non linear analyses

International Nuclear Information System (INIS)

Diaz, B.E.; Schulz, M.; Costa, E.; Vaz, L.E.

1984-01-01

A few important 1300 MW PWR nuclear power plants have been built over pile foundations. The design requirements of Nuclear Power Plants prescribe accurate investigation of the as built conditions of the foundation. This study must take into account the actual concrete strength existent among and along the pile shafts of the foundation. In order to simulate the structural response of the foundation up to the failure, a non linear analysis must be performed. In this paper the required computer analysis procedures will be described. It can be verified that the redistribution of the internal forces in this highly hyperstatic soil-structure system can be of two types. The total applied forces over the foundation are redistributed among the piles and for each pile itself a local redistribution of forces takes place along the pile shaft. This type of analysis allows an accurate investigation of the actual safety margin existent in the pile foundation, based on the actual as built conditions of the construction. (Author) [pt

Problem solving in foundation engineering using foundationPro

CERN Document Server

Yamin, Mohammad

2016-01-01

This book is at once a supplement to traditional foundation engineering textbooks and an independent problem-solving learning tool. The book is written primarily for university students majoring in civil or construction engineering taking foundation analysis and design courses to encourage them to solve design problems. Its main aim is to stimulate problem solving capability and foster self-directed learning. It also explains the use of the foundationPro software, available at no cost, and includes a set of foundation engineering applications. Taking a unique approach, Dr. Yamin summarizes the general step-by-step procedure to solve various foundation engineering problems, illustrates traditional applications of these steps with longhand solutions, and presents the foundationPro solutions. The special structure of the book allows it to be used in undergraduate and graduate foundation design and analysis courses in civil and construction engineering. The book stands as valuable resource for students, faculty, ...

Static Test and Result Analysis on Different Types of Pile Composite Foundation in the Same Field

Directory of Open Access Journals (Sweden)

Zhao Tuo

2015-01-01

Full Text Available Combining with the situation of soil test site, the large scale experiment was studying about natural foundation, rammed soil-cement piles, CFG pile and gravel pil. A series of conclusions were given from p-s curve, the fitting curve, and the Angle of the stress ratio of pile-soil composite modulus. It has certain guiding significance for the design and construction of pile type, which is used in North China area.

Site Study Plan for laboratory soil mechanics, Deaf Smith County site, Texas: Revision 1

International Nuclear Information System (INIS)

1987-12-01

This Site Study Plan for laboratory soil mechanics describes the laboratory testing to be conducted on soil samples collected as part of the characterization of the Deaf Smith County site, Texas. This study provides for measurements of index, mechanical, thermal, hydrologic, chemical, and mineral properties of soils from boring throughout the site. Samples will be taken from Playa Borings/Trenching, Transportation/Utilities Foundation Borings, Repository Surface Facilities Design Foundation Borings, and Exploratory Shaft Facilities Design Foundation Borings. Data from the laboratory tests will be used for soil strata characterization, design of foundations for surface structures, design of transportation facilities and utility structures, design of impoundments, design of shaft lining, design of the shaft freeze wall, shaft permitting, performance assessment calculations, and other program requirements. A tentative testing schedule and milestone log are given. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that appropriate documentation is maintained. 18 refs., 6 figs., 3 tabs

Releveling and behavior of strap-retrofitted damaged test foundations exposed to mine subsidence

International Nuclear Information System (INIS)

Marino, G.G.

1997-01-01

Test foundation walls were constructed in an area of planned subsidence. These crawl space-sized block bearing walls were located in the tension zone of a longwall panel. The test walls were 1.2 m (40 ft) long and were vertically loaded on top with soil binds to simulate the weight of a house. As the longwall proceeded past these test foundations, subsidence movements damaged the test structures. These damaged foundations were then structurally and aesthetically repaired by using a steel strap retrofit and applying a cementitious surface coating. The repaired test foundations underwent significant subsequent subsidence as an adjacent longwall was mined beneath. The response of the repaired foundation is summarized in this paper. The steel straps were also used to relevel another set of the test foundations after they were tilted and damaged by subsidence. First, the straps were applied to the block bearing walls, and then wall jacks were used to lift the upper portion of the walls to a level position. This releveling procedure is outlined with the results

Prediction of pile set-up for Ohio soils.

Science.gov (United States)

2011-02-01

ODOT typically uses small diameter driven pipe piles for bridge foundations. When a pile is driven into the subsurface, it disturbs and displaces the soil. As the soil surrounding the pile recovers from the installation disturbance, a time dependant ...

Analysis of static and dynamic pile-soil-jacket behaviour

Energy Technology Data Exchange (ETDEWEB)

Azadi, Mohammad Reza Emami

1998-12-31

In the offshore industry, recent extreme storms, severe earthquakes and subsidence of the foundation of jacket platforms have shown that new models and methods must take into account the jacket- pile-soil foundation interaction as well as the non-linear dynamic performance/loading effects. This thesis begins with a review of the state of art pile-soil interaction model, recognizing that most existing pile-soil models have been established based on large diameter pile tests on specific sites. The need for site independent and mechanistic pile-soil interaction models led to the development of new (t-z) and (p-y) disk models. These are validated using the available database from recent large diameter pile tests in the North Sea and Gulf of Mexico. The established static disk models are applied for non-linear static analysis of the jacket-pile-soil system under extreme wave loading. Dynamic pile-soil interaction is studied and a new disk-cone model is developed for the non-linear and non-homogeneous soils. This model is applied to both surface and embedded disks in a soil layer with non-linear properties. Simplified non-linear as well as more complex analysis methods are used to study the dynamic response of the jacket platform under extreme sea and seismic loading. Ductility spectra analysis is introduced and used to study the dynamic performance of the jacket systems near collapse. Case studies are used to illustrate the effects of structural, foundation failure characteristics as well as dynamic loading effects on the overall performance of the jacket-pile-soil systems near ultimate collapse. 175 refs., 429 figs., 70 tabs.

Soil-structure interaction for transient loads due to safety relief valve discharges

International Nuclear Information System (INIS)

Tseng, W.S.; Tsai, N.C.

1978-01-01

Dynamic responses of BWR Mark II containment structures subjected to axisymmetric transient pressure loadings due to simultaneous safety relief valve discharges were investigated using finite element analysis, including the soil-structure interaction effect. To properly consider the soil-structure interaction effect, a simplified lumped parameter foundation model and axisymmetric finite element foundation model with viscous boundary impedance are used. Analytical results are presented to demonstrate the effectiveness of the simplified foundation model and to exhibit the dynamic response behavior of the structure as the transient loading frequency and the foundation rigidity vary. The impact of the dynamic structural response due to this type of loading on the equipment design is also discussed. (Auth.)

Test Procedure for Axially Loaded Bucket Foundations in Sand (Large Yellow Box)

DEFF Research Database (Denmark)

Vaitkunaite, Evelina

This is a practical guide for preparing the soil, running a CPT test, installing a scaled bucket foundation model and running a test in the large yellow sand box cos(Kristina) in the geotechnical laboratory at Aalborg University. The test procedure is used for the examination of statically...... and cyclically axially loaded bucket foundation model In dense sand. The foundation model in scale of approximately 1:10 compared to the prototype size. The guide describes the step-by-step procedure for tests with and without surface pressure. A detailed description of test setup using the large yellow sand box...... for a monopile testing was provided by Thomassen (2015a), procedure for monopile testing can be found in Thomassen (2015b), while safety instructions were given by Vaitkunaite et al. (2014)....

Sustainable agriculture a challenge for soil microbiology

Directory of Open Access Journals (Sweden)

Nubia Moreno Sarmiento

2016-01-01

Full Text Available Soils: a solid foundation for life, was the theme of the celebration of 2015, the General Assembly of the UN, decides to declare as the International Year of Soils, considering that these are the foundation of agricultural development, the essential functions of ecosystems and food security. It is therefore a key to sustaining life on Earth element. During that year several actions that contributed to the awareness of their problems and protection of soil resources were made. One was that FAO, reviewed and published in June 2015, the World Soil Charter (originally developed in 1982. The World Soil Charter of Revised, as a preamble quote: 1. Soils are essential for life on Earth, but pressures on soil resources are reaching critical limits. Careful soil management is an essential factor of sustainable agriculture and also provides a valuable tool to regulate climate and a way to safeguard ecosystem services and biodiversity spring. 2. In the final document of the UN Conference on Sustainable Development, held in Rio de Janeiro (Brazil in June 2012, "The future we want" economic and social importance of good management is recognized land, including land, particularly its contribution to economic growth, biodiversity, sustainable agriculture, food security, poverty eradication, empowerment of women, measures to address climate change and increase water availability.

Evaluation of Thermal and Thermo-mechanical Behavior of Full-scale Energy Foundations

Science.gov (United States)

Murphy, Kyle D.

This study focuses on the thermo-mechanical and thermal behavior of full-scale energy foundations installed as part of two buildings recently constructed in Colorado. The soil stratigraphy at each of the sites differed, but both foundations were expected to function as primarily end-bearing elements with a tip socketed into rock. The heat exchanger configurations were also different amongst the foundations at both sites, permitting evaluation of the role of heat exchange. A common thread for both energy foundation case histories was the monitoring of the temperature and axial strain within the foundations during heat exchange operations. The first case study involves an evaluation of the long-term thermo-mechanical response of two full-scale energy foundations installed at the new Denver Housing Authority (DHA) Senior Living Facility at 1099 Osage St. in Denver, Colorado. Due to the construction schedule for this project, the thermal properties of the foundations and surrounding subsurface could not be assessed using thermal response tests. However, instrumentation was incorporated into the foundations to assess their long-term heat exchange response as well as the thermo-mechanical strains, stresses, and displacements that occurred during construction and operation of the ground-source heat pump system. The temperature changes within the foundations during heating and cooling operations over a period of approximately 600 days ranged from 9 to 32 °C, respectively. The thermal axial stresses in the foundations were calculated from the measured strains, and ranged from 3.1 MPa during heating to --1.0 MPa during cooling. These values are within reasonable limits for reinforced concrete structures. The maximum thermal axial stress was observed near the toe of both foundations, which is consistent with trends expected for end-bearing toe boundary conditions. The greatest thermal axial strains were observed near the top of the foundations (upward expansion during

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

Science.gov (United States)

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

2015-04-01

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

Set-up and Test Procedure for Suction Installation and Uninstallation of Bucket Foundation

DEFF Research Database (Denmark)

Koteras, Aleksandra Katarzyna

This technical report describes the set-up and the test procedures for installation and uninstallation of medium-scale model of bucket foundation that can be performed in the geotechnical part of laboratory in Aalborg University. The installation of bucket foundation can be tested with the use of......) and loading frame used for those tests have been already used for axially static and cyclic loading of piles (Thomassen, 2015a) and for axially static and cyclic loading of bucket foundation (Vaitkunaite et al., 2015).......This technical report describes the set-up and the test procedures for installation and uninstallation of medium-scale model of bucket foundation that can be performed in the geotechnical part of laboratory in Aalborg University. The installation of bucket foundation can be tested with the use...... of suction under the bucket lid or by applying additional force through the hydraulic piston, forcing the bucket to penetrate into the soil. Tests for uninstallation are performed also with the use of water pressure, as a reverse process to the suction installation. Both installation and uninstallation tests...

Virtual Soil Monoliths: Blending Traditional and Web-Based Educational Approaches

Science.gov (United States)

Krzic, Maja; Strivelli, Rachel A.; Holmes, Emma; Grand, Stephanie; Dyanatkar, Saeed; Lavkulich, Les M.; Crowley, Chris

2013-01-01

Since soil plays a crucial role in all aspects of global environmental change, it is essential that post-secondary institutions provide students with a strong foundation in soil science concepts including soil classification. The onset of information technology (IT) and web-based multimedia have opened new avenues to better incorporate…

Corporate Foundations

DEFF Research Database (Denmark)

Herlin, Heidi; Thusgaard Pedersen, Janni

2013-01-01

action between business and NGOs through convening, translation, collaboration, and mediation. Our study provides valuable insights into the tri-part relationship of company foundation NGO by discussing the implications of corporate foundations taking an active role in the realm of corporate social...... responsibility (CSR). The paper hence illuminates the fascinating and overlooked role of corporate foundations as potential bridges between business and civil society. It also informs theory on boundary organizations by clarifying challenges and limits of such institutions.......This paper aims to explore the potential of Danish corporate foundations as boundary organizations facilitating relationships between their founding companies and non-governmental organizations (NGOs). Hitherto, research has been silent about the role of corporate foundations in relation to cross...

Soil-structure interaction in fuel handling building

International Nuclear Information System (INIS)

Elaidi, B.M.; Eissa, M.A.

1998-01-01

This paper presents an accurate three-dimensional seismic soil-structure interaction analysis for large structures. The method is applied to the fuel building in nuclear power plants. The analysis is performed numerically in the frequency domain and the responses are obtained by inverse Fourier transformation. The size of the structure matrices is reduced by transforming the equation of motion to the modal coordinate system. The soil is simulated as a layered media on top of viscoelastic half space. Soil impedance matrices are calculated from the principles of continuum mechanics and account for soil stiffness and energy dissipation. Effects of embedment on the field equations is incorporated through the scattering matrices or by simply scaling the soil impedance. Finite element methods are used to discretize the concrete foundation for the generation of the soil interaction matrices. Decoupling of the sloshing water in the spent fuel pools and the free-standing spent fuel racks is simulated. The input seismic motions are defined by three artificial time history accelerations. These input motions are generated to match the ground design basis response spectra and the target power spectral density function. The methods described in this paper can handle arbitrary foundation layouts, allows for large structural models, and accurately represents the soil impedance. Time history acceleration responses were subsequently used to generate floor response spectra at applicable damping values. (orig.)

Forced vibration tests of a model foundation on rock ground

International Nuclear Information System (INIS)

Kisaki, N.; Siota, M.; Yamada, M.; Ikeda, A.; Tsuchiya, H.; Kitazawa, K.; Kuwabara, Y.; Ogiwara, Y.

1983-01-01

The response of very stiff structures, such as nuclear reactor buildings, to earthquake ground motion is significantly affected by radiation damping due to the soil-structure interaction. The radiation damping can be computed by vibration admittance theory or dynamical ground compliance theory. In order to apply the values derived from these theories to the practical problems, comparative studies between theoretical results and experimental results concerning the soil-structure interaction, especially if the ground is rock, are urgently needed. However, experimental results for rock are less easily obtained than theoretical ones. The purpose of this paper is to describe the harmonic excitation tests of a model foundation on rock and to describe the results of comparative studies. (orig./HP)

Foundation integrity assessment using integrated geophysical and geotechnical techniques: case study in crystalline basement complex, southwestern Nigeria

Science.gov (United States)

Olayanju, G. M.; Mogaji, K. A.; Lim, H. S.; Ojo, T. S.

2017-06-01

The determination of parameters comprising exact depth to bedrock and its lithological type, lateral changes in lithology, and detection of fractures, cracks, or faults are essential to designing formidable foundations and assessing the integrity of civil engineering structures. In this study, soil and site characterization in a typical hard rock geologic terrain in southwestern Nigeria were carried out employing integrated geophysical and geotechnical techniques to address tragedies in civil engineering infrastructural development. The deployed geophysical measurements involved running both very low frequency electromagnetic (VLF-EM) and electrical resistivity methods (dipole-dipole imaging and vertical electrical sounding (VES) techniques) along the established traverses, while the latter technique entailed conducting geological laboratory sieve analysis and Atterberg limit-index tests upon the collected soil samples in the area. The results of the geophysical measurement, based on the interpreted VLF-EM and dipole-dipole data, revealed conductive zones and linear features interpreted as fractures/faults which endanger the foundations of public infrastructures. The delineation of four distinct geoelectric layers in the area—comprised of topsoil, lateritic/clayey substratum, weathered layer, and bedrock—were based on the VES results. Strong evidence, including high degree of decomposition and fracturing of underlying bedrock revealed by the VES results, confirmed the VLF-EM and dipole-dipole results. Furthermore, values in the range of 74.2%-77.8%, 55%-62.5%, 23.4%-24.5%, 7.7%-8.2%, 19.5%-22.4%, and 31.65%-38.25% were obtained for these geotechnical parameters viz soil percentage passing 0.075 mm sieve size, liquid limit, plasticity index, linear shrinkage, natural moisture content, and plastic limit, respectively, resulting from the geotechnical analysis of the soil samples. The comparatively analyzed geophysical and geotechnical results revealed a high

An investigation of soil-structure interaction effects observed at the MIT Green Building

Science.gov (United States)

Taciroglu, Ertugrul; Çelebi, Mehmet; Ghahari, S. Farid; Abazarsa, Fariba

2016-01-01

The soil-foundation impedance function of the MIT Green Building is identified from its response signals recorded during an earthquake. Estimation of foundation impedance functions from seismic response signals is a challenging task, because: (1) the foundation input motions (FIMs) are not directly measurable, (2) the as-built properties of the super-structure are only approximately known, and (3) the soil-foundation impedance functions are inherently frequency-dependent. In the present study, aforementioned difficulties are circumvented by using, in succession, a blind modal identification (BMID) method, a simplified Timoshenko beam model (TBM), and a parametric updating of transfer functions (TFs). First, the flexible-base modal properties of the building are identified from response signals using the BMID method. Then, a flexible-base TBM is updated using the identified modal data. Finally, the frequency-dependent soil-foundation impedance function is estimated by minimizing the discrepancy between TFs (of pairs instrumented floors) that are (1) obtained experimentally from earthquake data and (2) analytically from the updated TBM. Using the fully identified flexible-base TBM, the FIMs as well as building responses at locations without instruments can be predicted, as demonstrated in the present study.

Assessment of Index Properties and Bearing Capacities of Soils for ...

African Journals Online (AJOL)

Mrs Owoyemi

on the physical properties and foundation bearing capacity of the soil in this area. This research aimed ... While many new structures are springing up daily in the .... plasticity soil. Most soil samples from both locations classify as A-2 -4 under the AASHTO classification system, rating as good subgrade materials. Bulk density ...

Failure envelope approach for consolidated undrained capacity of shallow foundations

OpenAIRE

Vulpe, Cristina; Gourvenec, Susan; Leman, Billy; Fung, Kah Ngii

2016-01-01

A generalized framework is applied to predict consolidated undrained VHM failure envelopes for surface circular and strip foundations. The failure envelopes for consolidated undrained conditions are shown to be scaled from those for unconsolidated undrained conditions by the uniaxial consolidated undrained capacities, which are predicted through a theoretical framework based on fundamental critical state soil mechanics. The framework is applied to results from small-strain finite-element anal...

Comparison between Dynamic Responses of Hollow and Solid Piles for Offshore Wind Turbine Foundations

DEFF Research Database (Denmark)

Bayat, Mehdi; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

2013-01-01

the dynamic behavior of soil and interaction between soil and piles. To avert damage to offshore foundation, it becomes necessary to identify and quantify the soil-structure interaction and the related damping effects on the system. In this study, a single pile is investigated by means of boundary integral...... equations. The pile is modeled as a solid or hollow cylinder and the dynamic excitation is applied vertically. The surface along the entire interface is considered rough and with full contact between the soil and the structure. Somigliana’s identity, Betti’s reciprocal theorem and Green’s function...... are employed to derive the dynamic stiffness of pile, assuming that the soil is a linear viscoelastic medium. The dynamic stiffness is compared for solid and hollow cylinders by considering different values of material properties including the material damping. Modes of resonance and anti...

Dynamic-stiffness matrix of embedded and pile foundations by indirect boundary-element method

International Nuclear Information System (INIS)

Wolf, J.P.; Darbre, G.R.

1984-01-01

The boundary-integral equation method is well suited for the calculation of the dynamic-stiffness matrix of foundations embedded in a layered visco-elastic halfspace (or a transmitting boundary of arbitrary shape), which represents an unbounded domain. It also allows pile groups to be analyzed, taking pile-soil-pile interaction into account. The discretization of this boundary-element method is restricted to the structure-soil interface. All trial functions satisfy exactly the field equations and the radiation condition at infinity. In the indirect boundary-element method distributed source loads of initially unknown intensities act on a source line located in the excavated part of the soil and are determined such that the prescribed boundary conditions on the structure-soil interface are satisfied in an average sense. In the two-dimensional case the variables are expanded in a Fourier integral in the wave number domain, while in three dimensions, Fourier series in the circumferential direction and bessel functions of the wave number domain, while in three dimensions, Fourier series in the circumferential direction and Bessel functions of the wave number in the radial direction are selected. Accurate results arise with a small number of parameters of the loads acting on a source line which should coincide with the structure-soil interface. In a parametric study the dynamic-stiffness matrices of rectangular foundations of various aspect ratios embedded in a halfplane and in a layer built-in at its base are calculated. For the halfplane, the spring coefficients for the translational directions hardly depend on the embedment, while the corresponding damping coefficients increase for larger embedments, this tendency being more pronounced in the horizontal direction. (orig.)

Determination of p-y Curves using Finite Element Modelling for Bucket Foundation in Undrained Soft and Medium Clay

DEFF Research Database (Denmark)

Hvidberg, Mogens Bonde; Ibsen, Lars Bo

In many years the types of foundation, such as monopiles and bucket foundation which are used in the offshore wind turbine industry, have been analysed analytically with formulations that are based on much slender piles, than are used today. Because of that, the analytical calculation...... is not describing the connection between the horizontal bearing capacity of the soil and the displacement of the foundation accurate, in particular for the bucket foundation because of the much smaller slenderness of the profile. Numerical modelling is used to examine that bearing capacity the bucket foundation has...... in soft and medium clay at different dimensions of the bucket, to a horizontal displacement. After that a mathematical formulation is determined, based on (Reese et al, 1975), so it is possible to get a more accurate result in an analytical calculation....

Interação solo-estrutura para edifícios sobre fundações rasas = Soil-structure interaction for buildings bearing on shallow foundations

Directory of Open Access Journals (Sweden)

Rafael Alves de Souza

2008-07-01

Full Text Available A hipótese de apoios totalmente rígidos (fundações engastadas ou rotuladas para as condições de vinculação de edifícios em concreto armado vem sendo utilizada há muito tempo pelos engenheiros de estruturas. Tal fato se deve, principalmente, à grande dificuldade que se tinha no passado em analisar manualmente edifícios sobre apoios flexíveis. Porém, com a chegada dos microcomputadores e com o desenvolvimento de diversos programas computacionais, já se pode usufruir de análises mais realistas, que levam em consideração a deformabilidade do solo adjacente às fundações. No entanto, observa-seque os engenheiros estruturais continuam utilizando o mesmo modelo simplificado do passado, provavelmente pela falta de informações ou talvez pela falta de maior interação com os engenheiros de fundações. Neste contexto, o presente trabalho tem por objetivo apresentar recomendações práticas para a aplicação da interação solo-estrutura.Adicionalmente, demonstra-se que a hipótese de apoios totalmente rígidos pode levar a importantes distorções nos esforços obtidos para os pilares de edifícios em concreto armado pelos exemplos práticos.The assumption of perfect supports (fixed or pinned foundations for the boundary conditions of reinforced concrete buildings has been used for many years by structural engineers. This fact is mainly attributed to the great difficulties faced in the past, when designers needed to calculate buildings by using manual methods. Nowadays, realistic analysis that takes into account the deformability of the adjacent soil foundation is possible,based on the development of powerful computers and computational software packages. However, many structural engineers still use the same simplified boundary conditions widely used in the past. The main explanation for this problem may be the lack of information and models available in the literature, as well as the lack of interaction between structural

The transformation of weak saturated soils using piles-drains for improving its mechanical properties

Science.gov (United States)

Ter-Martirosyan, Z. G.; Ter-Martirosyan, A. Z.; Sidorov, V. V.

2018-04-01

In practice of increased responsibility structures design there are often weak saturated clayey soils with low characteristics of deformability and strength take place on the construction site. In these cases, foundations using piles-drains of sandy or coarse material are recommended by norms, which is able to bear the load and to accelerate the consolidation process. The presented solutions include an analytical solution of the interaction problem between piles and slab raft foundation with the surrounding soil of the base with the possibility of extension of pile shaft. The closed-form solutions to determine the stresses in pile shaft and in the soil under the foundation slab are obtained. The article presents the results of large scale tests in the pilot area construction of major energy facilities in Russia.

Influence of aging on bearing capacity of circular footing resting on soft soil

Directory of Open Access Journals (Sweden)

Mohamed B.D. Elsawy

2013-12-01

Full Text Available Structures constructed on soft soil are considered to be at risk due to its low shear strength and high compressibility. Thus constructed structures on soft soil are designed according to its undrained shear strength, representing the bearing capacity of the shallow foundation in the short term conditions, which varies with time under the applied load. The bearing capacity in short term conditions is limited because of the generation of excess pore water pressure as soon as the initial loads are applied. Hence in this paper, the bearing capacity of shallow foundations on soft soil is studied by varying the time and the applied loads. The shallow foundation is subjected to a series of applied loads and consolidation phases to study the effect of aging. The study is investigated by means of finite element analyses taking account of consolidation processes in the ground, in which the soft soil is modeled using the Soft Soil model. The analysis is performed by finite element package of Plaxis program. The numerical analysis clears that the bearing capacity in the long term conditions is enhanced and has a significant enhancement following each consolidation phase when compared with the short term conditions.

Pile foundation of nuclear power plant structures

International Nuclear Information System (INIS)

Jurkiewicz, W.J.; Thomaz, E.; Rideg, P.; Girao, M.

1978-01-01

The subject of pile foundation used for nuclear power plant structures, considering the experience gained by the designers of the Angra Nuclear Power Plant, Units 2 and 3 in Brazil is dealt with. The general concept of the pile foundations, including types and execution of the piles, is described briefly. Then the two basic models, i.e. the static model and the dynamic one, used in the design are shown, and the pertinent design assumptions as related to the Angra project are mentioned. The criteria which established the loading capacity of the piles are discussed and the geological conditions of the Angra site are also explained briefly, justifying the reasons why pile foundations are necessary in this project. After that, the design procedures and particularly the tools - i.e. the computer programs - are described. It is noted that the relatively simple but always time consuming job of loading determination calculations can be computerized too, as it was done on this project through the computer program SEASA. The interesting aspects of soil/structure interaction, applicable to static models, are covered in detail, showing the theoretical base wich was used in the program PILMAT. Then the advantage resulting from computerizing of the job of pile reinforcement design are mentioned, describing briefly the jobs done by the two special programs PILDES and PILTAB. The point is stressed that the effort computerizing the structural design of this project was not so much due to the required accuracy of the calculations, but mainly due to the need to save on the design time, as to allow to perform the design task within the relatively tight time schedule. A conclusion can be drawn that design of pile foundations for nuclear power plant structures is a more complex task than the design of bearing type of foundation for the same structures, but that the task can be always made easier when the design process can be computerized. (Author)

Design of dry sand soil stratified sampler

Science.gov (United States)

Li, Erkang; Chen, Wei; Feng, Xiao; Liao, Hongbo; Liang, Xiaodong

2018-04-01

This paper presents a design of a stratified sampler for dry sand soil, which can be used for stratified sampling of loose sand under certain conditions. Our group designed the mechanical structure of a portable, single - person, dry sandy soil stratified sampler. We have set up a mathematical model for the sampler. It lays the foundation for further development of design research.

An impedance function approach for soil-structure interaction analyses including structure-to-structure interaction effects

International Nuclear Information System (INIS)

Gantayat, A.; Kamil, H.

1981-01-01

The dynamic soil-structure and structure-to-structure interaction effects may be determined in one of the two ways: by modeling the entire soil-structure system by a finite-element model, or by using a frequency-dependent (or frequency-independent) impedance function approach. In seismic design of nuclear power plant structures, the normal practice is to use the first approach because of its simplicity and easy availability of computer codes to perform such analyses. However, in the finite-element approach, because of the size and cost restrictions, the three-dimensional behavior of the entire soil-structure system and the radiation damping in soil are only approximately included by using a two-dimensional finite-element mesh. In using the impedance function approach, the soil-structure analyses can be performed in four steps: (a) determination of the dynamic properties of the fixed base superstructure, (b) determination of foundation and structure impedance matrices and input motions, (c) evaluation of foundation motion, (d) analysis of the fixed base superstructure using computed foundation motion. (orig./RW)

Numerical Analysis of Slopes Stability and Shallow Foundations Behavior at Crest under Real Seismic Loading - Reinforcement Effect

International Nuclear Information System (INIS)

Mekdash, H.; Hage Chehade, F.; Sadek, M.; Abdel Massih, D.; El Hachem, E.; Youssef, E.

2011-01-01

The aim of this paper is to analyze the slopes stability under seismic loading using a global numerical dynamic approach. This approach allows important parameters that are generally ignored by traditional engineering methods such as the soil deformability, the dynamic amplification, non linear soil behavior, the spatial and temporal variability of the seismic loading and the reinforcement element. The present study is conducted by using measures recorded during real earthquakes (Turkey, 1999) and (Lebanon, 2008). Elastoplastic soil behavior analysis leads to monitor the evolution of the slope state after an earthquake and to clarify the most probable failure circles. A parametric study according to the reinforcement length, position, inclination and the number of elements has been studied in order to define the optimal reinforcement scheme for slopes under seismic loading. This study contains also the stability analysis of an existing foundation near the slope's crest. It will focus on the reinforcement in order to give recommendation for the most appropriate scheme that minimize the settlement of the foundation due to earthquake effect. (author)

Prediction of pile set-up for Ohio soils : executive summary report.

Science.gov (United States)

2011-02-01

ODOT typically uses small diameter driven pipe piles for bridge foundations. When a pile is driven into the subsurface, it disturbs and displaces the soil. As the soil surrounding the pile recovers from the installation disturbance, a time dependant ...

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

Directory of Open Access Journals (Sweden)

Andrea Koch

2015-04-01

Full Text Available The Australian National Soil Research, Development and Extension Strategy identifies soil security as a foundation for the current and future productivity and profitability of Australian agriculture. Current agricultural production is attenuated by soil degradation. Future production is highly dependent on the condition of Australian soils. Soil degradation in Australia is dominated in its areal extent by soil erosion. We reiterate the use of soil erosion as a reliable indicator of soil condition/quality and a practical measure of soil degradation. We describe three key phases of soil degradation since European settlement, and show a clear link between inappropriate agricultural practices and the resultant soil degradation. We demonstrate that modern agricultural practices have had a marked effect on reducing erosion. Current advances in agricultural soil management could lead to further stabilization and slowing of soil degradation in addition to improving productivity. However, policy complacency towards soil degradation, combined with future climate projections of increased rainfall intensity but decreased volumes, warmer temperatures and increased time in drought may once again accelerate soil degradation and susceptibility to erosion and thus limit the ability of agriculture to advance without further improving soil management practices. Monitoring soil degradation may indicate land degradation, but we contend that monitoring will not lead to soil security. We propose the adoption of a triaging approach to soil degradation using the soil security framework, to prioritise treatment plans that engage science and agriculture to develop practices that simultaneously increase productivity and improve soil condition. This will provide a public policy platform for efficient allocation of public and private resources to secure Australia’s soil resource.

Soil washing treatability study

International Nuclear Information System (INIS)

Krstich, M.

1995-12-01

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

Analytical Analysis and Field Test Investigation of Consolidation for CCSG Pile Composite Foundation in Soft Clay

Directory of Open Access Journals (Sweden)

Jin Yu

2013-01-01

Full Text Available Low-grade concrete-cored sand-gravel (CCSG pile composite foundation is a new kind of composite foundation for thick and soft clay ground treatment. An analytical solution was derived for calculating the consolidation process of this composite foundation by considering coefficients of horizontal permeability in smear zone, the radial flow within the sand-gravel shell, and the impervious property of concrete-cored pile. The results show that Terzaghi’s one-dimensional consolidation solution and the consolidation analytical solution of ordinary composite foundation were special cases of this solution. Curves of the average consolidation degree of the composite foundation under various nondimensional parameters were observed using the program based on the theoretical formula. Meanwhile, a series of in situ measurements including the settlement of pile and soil, the pore water pressure, and the total stress under embankment load were obtained on the CCSG pile composite foundation on a section of Zhenjiang-Liyang highway. The analyzed results show that the new style composite foundation patent technology has many advantages such as small differential postconstruction settlement (differential is not good, small is, reliable quality, high bearing capacity, and stability. And the consolidation of composite foundation is largely affected by the nondimensional parameters. The analytical solution is finally verified with the actual measurement data.

THE MATHEMATICAL BASIS FOR THE THEORY OF JOINT WORK OF THE FOUNDATION AND THE FOUNDATION WITH THE „ARCH” EFFECT

Directory of Open Access Journals (Sweden)

TIMCHENKO R. A.

2016-01-01

Full Text Available Statement of the problem. The review of the technical solutions of the foundation of buildings and structures revealed a number of significant shortcomings associated with the complexity of structures and a low probability of normal functioning in difficult engineering-geological conditions. When designing the building use and design measures that reduce either the amount of strain-tive effects from the base, or their impact on the structure. Experience in construction has shown that it is not always possible to completely prevent the adverse effects on structures from the base. Therefore, their effect on the structure still considered at the design stage. Purpose. On the basis of experimental and theoretical studies to justify the proposed theory of joint work the plate foundation-selfregulators (PFS with the base, including the theory of plasticity (maximum stress state and soil pressure on roofs with. Conclusion. Of all the discussed features of the joint work the PFS with the base surface is more important "arch" effect, since it is the resultant and explains the stress-strain state (SSS for PFS. Increased design resistance at 15-22% is due to the design of the PFS and the special nature of the formation of the overall limit of the SSS of the base with an increase in load to the limit values. For the construction of the PFS by more uniform distribution of the contact stresses in the ground under the foundation, regardless of the power or influence of the deformation, and large outside the proportional relationship between stress and strain. Establish the boundaries of self-regulation can be obtained by carrying out mathematical modeling of changing the compensatory possibilities of the foundation.

Modelling of pile load tests in granular soils : Loading rate effects

NARCIS (Netherlands)

Nguyen, T.C.

2017-01-01

People have used pile foundations throughout history to support structures by transferring
loads to deeper and stronger soil layers. One of the most important questions during the design of the pile foundation is the bearing capacity of the pile. The most reliable method for determining the

The Reflective Foundation

DEFF Research Database (Denmark)

Lunde Jørgensen, Ida

Private foundations and cultural philanthropy by élites is viewed with increasing skepticism in recent years, begging the question of the extent to which foundations reflect on their role vis a vis wider societal norms. Through the prism of the New Carlsberg Foundation, financed by the brewery...... Carlsberg A/S, the paper seeks to elucidate the way in which one culturally significant foundation from Denmark has reflected on - and legitimated - its work and investments at critical moments in the past decades. The paper indicates a foundation with a high degree of reflection on the wider societal...

Bore pile foundation tall buildings closed in the heritage building

Science.gov (United States)

Triastuti, Nusa Setiani

2017-11-01

Bore pile foundation for high building surroundings heritage building should be not damage. Construction proses must good, no necking, no mixed deep water, no sliding soil, nonporous concrete. Objective the execution of bore pile so that heritage buildings and neighboring buildings that are old do not experience cracks, damage and tilting. The survey methodology was observe the process of the implementation of the dominant silt, clay soil, in addition a limited space and to analyze the results of loading tests, investigations of soil and daily reports. Construction process determines the success of the structure bore pile in high building structure bearing, without damaging a heritage building. Attainment the hard soil depth, density concrete, observable clean reinforcement in the implementation. Monitoring the implementation of, among others, the face of the ground water little reduce in the area and outside the footprint of the building, no impact of vibration drilling equipment, watching the mud content on the water coming out at the time of drilling, concrete volume was monitored each 2 m bore depth of pile, The result researched heritage building was not damage. The test results bore pile axial, lateral analyzed the results have the appropriate force design required.

Soil-structure interaction effects on containment fragilities and floor response spectra statistics

International Nuclear Information System (INIS)

Pires, J.; Reich, M.; Chokshi, N.C.

1987-01-01

The probability-based method for the reliability evaluation of nuclear structures developed at Brookhaven National Laboratory (BNL) is extended to include soil-structure interaction effects. A reinforced concrete containment is analyzed in order to investigate the soil-structure interaction effects on: structural fragilities; floor response spectra statistics and acceleration response correlations. To include the effect of soil flexibility on the reliability assessment the following two step approach is used. In the first step, the lumped parameter method for soil-structure interaction analysis is used together with a stick model representation of the structure in order to obtain the motions of the foundation plate. These motions, which include both translations and rotations of the foundation plate, are expressed in terms of the power-spectral density of the free-field ground excitation and the transfer function of the total acceleration response of the foundation. The second step involves a detailed finite element model of the structure subjected to the interaction motions computed from step one. Making use of the structural model and interaction motion the reliability analysis method yields the limit stat probabilities and fragility data for the structure

Effect of foundation flexibility on the vibrational stability of the National Ignition Facility optical system support structures

International Nuclear Information System (INIS)

McCallen, D.

1997-01-01

Alignment requirements for the National Ignition Facility (NIF) optical components will require a number of support structures which minimize the system displacements and deformations. The stringent design requirements for this facility will result in a system in which vibrations due to ambient environmental loads (e.g. foundation motion due to typical traffic loads, microseisms or nearby equipment) will have a significant, and perhaps predominant, influence on the design of the supporting structures. When considering the total deformations and displacements of the structural systems, the contribution of the foundation to the overall system flexibility must be addressed. Classical fixed-base structural analyses, which are predicated on an assumption of an infinitely rigid foundation system, neglect the influence of foundation flexibility and for the vibration regime in which the NIF structures reside, may result in significant underestimation of the system ambient vibration displacements. In the work described herein, parametric studies were performed in order to understand the potential contributions of soil-structure- interaction (SSI) to optical system displacements. Time domain finite element analyses were employed to quantify the effect of wave scattering by the mat foundation and the effects of inertial SSI due to the rocking of the massive shear wall support structures. A simplified procedure is recommended for accounting for SSI effects in the design of the special equipment structures. The simplified approach consists of applying a scale factor to displacements obtained from fixed base analyses to approximately account for the effects of soil-structure interaction and variable support input motion

Safe jack-up method permits repairs of tank bottoms and foundations

International Nuclear Information System (INIS)

de Wit, J.

1991-01-01

The oil and chemical industries use many thousands of steel tanks to store crude oil, oil products, and chemical liquids. The majority of these tanks are 30-40 years old. Tank bottoms are likely to begin leaking in the coming years, as these tanks get older. The European technique of jacking up a tank and repairing its foundation allows the thorough inspection of the underside of the tank bottom and the removal of saturated foundation material. And the possibility of soil and groundwater pollution is reduced to a minimum. With good, regular maintenance, the lifetime of a storage tank is very long. But experience has shown that special attention should be paid to the tank's bottom. Tank bottoms are only 5 or 6 mm thick, and in the last 10 years, an increasing number of leaks in tank bottoms have been reported. Tank foundations are affected by these leaks. This article describes the resulting procedure, which is used successfully in many European countries, but is not yet common in the U.S

Contribution to Estimating Bearing Capacity of Pile in Clayey Soils

Science.gov (United States)

Drusa, Marián; Gago, Filip; Vlček, Jozef

2016-12-01

The estimation of real geotechnical parameters is key factor for safe and economic design of geotechnical structures. One of these are pile foundations, which require proper design and evaluation due to accessing more deep foundation soil and because remediation work of not bearable piles or broken piles is a crucial operation. For this reason, geotechnical field testing like cone penetration test (CPT), standard penetration (SPT) or dynamic penetration test (DP) are realized in order to receive continuous information about soil strata. Comparing with rotary core drilling type of survey with sampling, these methods are more progressive. From engineering geologist point of view, it is more important to know geological characterization of locality but geotechnical engineers have more interest above the real geotechnical parameters of foundation soils. The role of engineering geologist cannot be underestimated because important geological processes in origin or during history can explain behaviour of a geological environment. In effort to streamline the survey, investigation by penetration tests is done as it is able to provide enough information for designers. This paper deals with actual trends in pile foundation design; because there are no new standards and usable standards are very old. Estimation of the bearing capacity of a single pile can be demonstrated on the example of determination of the cone factor Nk from CPT testing. Then results were compared with other common methods.

Contribution to Estimating Bearing Capacity of Pile in Clayey Soils

Directory of Open Access Journals (Sweden)

Drusa Marián

2016-12-01

Full Text Available The estimation of real geotechnical parameters is key factor for safe and economic design of geotechnical structures. One of these are pile foundations, which require proper design and evaluation due to accessing more deep foundation soil and because remediation work of not bearable piles or broken piles is a crucial operation. For this reason, geotechnical field testing like cone penetration test (CPT, standard penetration (SPT or dynamic penetration test (DP are realized in order to receive continuous information about soil strata. Comparing with rotary core drilling type of survey with sampling, these methods are more progressive. From engineering geologist point of view, it is more important to know geological characterization of locality but geotechnical engineers have more interest above the real geotechnical parameters of foundation soils. The role of engineering geologist cannot be underestimated because important geological processes in origin or during history can explain behaviour of a geological environment. In effort to streamline the survey, investigation by penetration tests is done as it is able to provide enough information for designers. This paper deals with actual trends in pile foundation design; because there are no new standards and usable standards are very old. Estimation of the bearing capacity of a single pile can be demonstrated on the example of determination of the cone factor Nk from CPT testing. Then results were compared with other common methods.

Application of multilinear regression analysis in modeling of soil ...

African Journals Online (AJOL)

The application of Multi-Linear Regression Analysis (MLRA) model for predicting soil properties in Calabar South offers a technical guide and solution in foundation designs problems in the area. Forty-five soil samples were collected from fifteen different boreholes at a different depth and 270 tests were carried out for CBR, ...

Developing a Foundation for Constructing New Curricula in Soil, Crop, and Turfgrass Sciences

Science.gov (United States)

Jarvis, Holly D.; Collett, Ryan; Wingenbach, Gary; Heilman, James L.; Fowler, Debra

2012-01-01

Some soil and crop science university programs undergo curricula revision to maintain relevancy with their profession and/or to attract the best students to such programs. The Department of Soil and Crop Sciences at Texas A&M University completed a thorough data gathering process as part of its revision of the undergraduate curriculum and…

Study Added of Waste Chicken Egg Shell in Soils

Directory of Open Access Journals (Sweden)

Keng Wong Irwan Lie

2016-01-01

Full Text Available Soil is the foundation of structure or construction that will receive the load transfer through to foundation. If the soil has a carrying capacity of small and cannot withstand the load transfer can result in the failure of construction. If the soil has a carrying capacity of small ground it is necessary to stabilize or improve the soil so that an increase in the carrying capacity of the land so that it can be used for construction. One material is commonly used for soil stabilization with the addition of lime. Waste chicken egg shell is waste that is still rarely used, the results of research [1], states that composition egg shell broadly consists of water (1,6% and dry material (98,4%. The total dry ingredients are there, in shell eggs contained mineral elements (95,1% and protein (3,3%. Based on the existing mineral composition, then the egg shells are composed of crystalline CaCO3 (98,43%, MgCO3 (0,84% and Ca3(PO42 (0,75%. This research was done by adding powdered chicken egg shell waste in clay with a composition of 5%, 7,5%, 10% and 14% with physical properties test and soil compaction test.

Design of a New Foundation for Offshore Wind Turbines

DEFF Research Database (Denmark)

Ibsen, Lars Bo; Brincker, Rune

2004-01-01

was installed at the test field in Frederikshavn in late 2003, with a 3 MW wind turbine in normal operation. The R&D work is continued the complete the bucket concept and having the design standards for the construction and installation methodologies recognised. The design saves about half of the steel weight...... as compared to a traditional pile foundation, it is much easier to install and it can easily be removed when the wind turbine is taken down. However, the new design is suffering from uncertainties in the accumulated fatigue in the both the steel structure and the surrounding earth material. Therefore an on......The gravitation platform and the monopile have in the previous major offshore wind turbine projects been dominating. A four-year research and development project has proven the bucket foundation to be feasible in suitable soil condition in water depth from near shore to app. 40 meters. A prototype...

ABIM Foundation

Science.gov (United States)

... In conjunction with the… mailchi.mp View on Facebook ABIM Foundation shared Business Radio Powered by The Wharton School's post. 2 days ago View on Facebook ABIM Foundation 2 days ago The Android version ...

Time-domain soil-structure interaction analysis of nuclear facilities

International Nuclear Information System (INIS)

Coleman, Justin L.; Bolisetti, Chandrakanth; Whittaker, Andrew S.

2016-01-01

The Nuclear Regulatory Commission (NRC) regulation 10 CFR Part 50 Appendix S requires consideration of soil-structure interaction (SSI) in nuclear power plant (NPP) analysis and design. Soil-structure interaction analysis for NPPs is routinely carried out using guidance provided in the ASCE Standard 4-98 titled “Seismic Analysis of Safety-Related Nuclear Structures and Commentary”. This Standard, which is currently under revision, provides guidance on linear seismic soil-structure-interaction (SSI) analysis of nuclear facilities using deterministic and probabilistic methods. A new appendix has been added to the forthcoming edition of ASCE Standard 4 to provide guidance for time-domain, nonlinear SSI (NLSSI) analysis. Nonlinear SSI analysis will be needed to simulate material nonlinearity in soil and/or structure, static and dynamic soil pressure effects on deeply embedded structures, local soil failure at the foundation-soil interface, nonlinear coupling of soil and pore fluid, uplift or sliding of the foundation, nonlinear effects of gaps between the surrounding soil and the embedded structure and seismic isolation systems, none of which can be addressed explicitly at present. Appendix B of ASCE Standard 4 provides general guidance for NLSSI analysis but will not provide a methodology for performing the analysis. This paper provides a description of an NLSSI methodology developed for application to nuclear facilities, including NPPs. This methodology is described as series of sequential steps to produce reasonable results using any time-domain numerical code. These steps require some numerical capabilities, such as nonlinear soil constitutive models, which are also described in the paper.

Reliability evaluation of containments including soil-structure interaction

International Nuclear Information System (INIS)

Pires, J.; Hwang, H.; Reich, M.

1985-12-01

Soil-structure interaction effects on the reliability assessment of containment structures are examined. The probability-based method for reliability evaluation of nuclear structures developed at Brookhaven National Laboratory is extended to include soil-structure interaction effects. In this method, reliability of structures is expressed in terms of limit state probabilities. Furthermore, random vibration theory is utilized to calculate limit state probabilities under random seismic loads. Earthquake ground motion is modeled by a segment of a zero-mean, stationary, filtered Gaussian white noise random process, represented by its power spectrum. All possible seismic hazards at a site, represented by a hazard curve, are also included in the analysis. The soil-foundation system is represented by a rigid surface foundation on an elastic halfspace. Random and other uncertainties in the strength properties of the structure, in the stiffness and internal damping of the soil, are also included in the analysis. Finally, a realistic reinforced concrete containment is analyzed to demonstrate the application of the method. For this containment, the soil-structure interaction effects on; (1) limit state probabilities, (2) structural fragility curves, (3) floor response spectra with probabilistic content, and (4) correlation coefficients for total acceleration response at specified structural locations, are examined in detail. 25 refs., 21 figs., 12 tabs

Principles of control automation of soil compacting machine operating mechanism

Science.gov (United States)

Anatoly Fedorovich, Tikhonov; Drozdov, Anatoly

2018-03-01

The relevance of the qualitative compaction of soil bases in the erection of embankment and foundations in building and structure construction is given.The quality of the compactible gravel and sandy soils provides the bearing capability and, accordingly, the strength and durability of constructed buildings.It has been established that the compaction quality depends on many external actions, such as surface roughness and soil moisture; granulometry, chemical composition and degree of elasticity of originalfilled soil for compaction.The analysis of technological processes of soil bases compaction of foreign and domestic information sources showed that the solution of such important problem as a continuous monitoring of soil compaction actual degree in the process of machine operation carry out only with the use of modern means of automation. An effective vibrodynamic method of gravel and sand material sealing for the building structure foundations for various applications was justified and suggested.The method of continuous monitoring the soil compaction by measurement of the amplitudes and frequencies of harmonic oscillations on the compactible surface was determined, which allowed to determine the basic elements of facilities of soil compacting machine monitoring system of operating, etc. mechanisms: an accelerometer, a bandpass filter, a vibro-harmonics, an on-board microcontroller. Adjustable parameters have been established to improve the soil compaction degree and the soil compacting machine performance, and the adjustable parameter dependences on the overall indexhave been experimentally determined, which is the soil compaction degree.A structural scheme of automatic control of the soil compacting machine control mechanism and theoperation algorithm has been developed.

The Theoretical Study of the Beams Supported on a Straining Environment as an Interaction Problem Soil - Structure - Infrastructure Interaction

Directory of Open Access Journals (Sweden)

Ana-Raluca Chiriac

2006-01-01

Full Text Available Between structure, infrastructure (foundation and soil there is an effective interaction, which has to be taken into account as correctly as possible every time we do the calculation. This effective interaction can be analysed in a global form, considering on one hand the entire building, and on the other hand the soil -- establishment surface, or in an analytical form: we consider first the soil -- infrastructure (foundation interaction and then the structure -- infrastructure one. Without considering the interaction, we cannot make neither the calculation (for the soil according to the limiting deformation state which has to be compatible with the structure’s resistance system, nor calculation for the limiting resistance state, because the correct distribution of efforts along the contact surface between the soil and the structure is unknown, so we cannot determine the zones of plastical equilibrium in the soil massive and the conditions of limited equilibrium. Also, without considering the infrastructure, we cannot correctly calculate the efforts and the deformations which may occur in all resistance elements of the building. Therefore, we cannot talk about limiting state calculation without considering the interaction between the soil and the structure itself. The problem of interaction between building, on one hand and soil foundation, on the other hand, is not approached very much in the specialized literature, because of the big difficulties raised by summarizing all the factors that describe the structure and the environment, which would be more accessible to a practical calculation. A lot of buildings or elements of buildings standing on the soil or on another environment with finite rigidity can be taken into account as beams supported on a straining environment, (continuous foundations, resistance walls, longitudinal and transversal membranes of civil and industrial buildings, hydrotechnic works. Therefore, in the present paper we

MODEL TESTS AND 3D ELASTIC FINITE ELEMENT ANALYSIS FOR STEEL PIPE PILES WITH WINGS IN STALLED IN SOIL CEMENT COLUMN

Science.gov (United States)

Tamai, Toshiyuki; Teramoto, Shuntarou; Kimura, Makoto

Steel pipe piles with wings installed in soil cement column is a composite foundation of pile consisting of soil improvement with cement and steel pipe with wings. This type of pile shows higher vertical bearing capacity when compared to steel pipe piles that are installed without soil cement. It is thought the wings contribute to higher bearing capacity of this type of piles. The wings are also thought to play the role of structural unification of pile foundations and load transfer. In this study, model test and 3D elastic finite element analysis was carried out in order to elucidate the effect of wings on the structural unification of pile foundation and the load transfer mechanism. Firstly, the model test was carried out in order to grasp the influence of pile with and without wings, the shape of wings of the pile and the unconfined compression strength of the soil cement on the structural unification of the pile foundation. The numerical analysis of the model test was then carried out on the intermediate part of the pile foundation with wings and mathematical model developed. Finally load tran sfer mechanism was checked for the entire length of the pile through this mathematical model and the load sharing ratio of the wings and stress distribution occurring in the soil cement clarified. In addition, the effect of the wing interval on the structural unification of the pile foundation and load transfer was also checked and clarified.

Assessing soil quality: practicable standards for sustainable forest productivity in the United States

Science.gov (United States)

Robert F. Powers; Allan E. Tiarks; James R. Boyle

1998-01-01

Productive soils form the foundation for productive forests. But unfortunately, the significance of soil seems lost to modem society. Most of us are too far removed from the natural factors of production to appreciate the multiple roles of soil. Nor is its worth recognized well by many forest managers who too often see soil only in its capacity for logging roads and...

A sensitivity study for soil-structure interaction

International Nuclear Information System (INIS)

Kunar, R.R.; White, D.C.; Ashdown, M.J.; Waker, C.H.; Daintith, D.

1981-01-01

This paper presents the results of a study in which the sensitivity of a containment building typical of one type of construction used in the nuclear reprocessing industry is examined for variations in soil data and seismic input. A number of dynamic soil-structure interaction analyses are performed on the structure and its foundations using parametric variations of the depth of soil layer, soil material properties, bedrock flexibility, seismic input location and time and phase characteristics of the earthquake excitation. Previous experience is combined with the results obtained to gneralise conclusions regarding the conditions under which each of the uncertainties will be significant enough to merit proper statistical treatment. (orig.)

Seismic Material Properties of Reinforced Concrete and Steel Casing Composite Concrete in Elevated Pile-Group Foundation

Directory of Open Access Journals (Sweden)

Zhou Mi

2015-09-01

Full Text Available The paper focuses on the material mechanics properties of reinforced concrete and steel casing composite concrete under pseudo-static loads and their application in structure. Although elevated pile-group foundation is widely used in bridge, port and ocean engineering, the seismic performance of this type of foundation still need further study. Four scale-specimens of the elevated pile-group foundation were manufactured by these two kinds of concrete and seismic performance characteristic of each specimen were compared. Meanwhile, the special soil box was designed and built to consider soil-pile-superstructure interaction. According to the test result, the peak strength of strengthening specimens is about 1.77 times of the others and the ultimate displacement is 1.66 times of the RC specimens. Additionally, the dissipated hysteric energy capability of strengthening specimens is more than 2.15 times of the others as the equivalent viscous damping ratio is reduced by 50%. The pinching effect of first two specimens is more obvious than latter two specimens and the hysteretic loops of reinforced specimens are more plumpness. The pseudo-static tests also provided the data to quantitatively assessment the positive effect of steel casing composite concrete in aseismatic design of bridge.

Environmental Foundations in Germany

Directory of Open Access Journals (Sweden)

Thomas Krikser

2015-05-01

Full Text Available Foundations in Germany were examined in the context of environmental issues. Data from environmental foundations show that there is huge difference between private and public foundations concerning financial settings. Furthermore, environment is often not the only objective and sometimes not even processed. Our analysis shows that there are different types of foundations with regard to environmental scopes and activities. Although “attractive topics” such as biodiversity and landscape conservation seem to be more important to foundations, less visible topics such as pollution prevention remain merely a “blind spot.” Together, these findings suggest that there is only a limited potential of private foundations compared with public foundations. Nevertheless, there might be an impact on environmental awareness and local sustainability.

CONDUCTING AND ANALYZING THE RESULTS OF THE EXPERIMENTAL BOX TEST OF RETAINING WALL MODELS WITHOUT PILES AND ON THE PILE FOUNDATION

Directory of Open Access Journals (Sweden)

M. A. Lisnevskyi

2015-08-01

Full Text Available Purpose. Taking into consideration that the bearing capacity of the foundation may be insufficient, in the study it is assumed that pile foundation can be used to reduce the impact of the construction of new retaining structures on roads and railways near the existing buildings or in areas of dense urban development and ensure the stability of the foundation. To reduce the volume of excavation it is necessary to choose the economic structure of the retaining wall. To do this, one should explore stress-strain state (SSS of the retaining walls, to develop methods to improve their strength and stability, as well as to choose the most appropriate method of their analysis. Methodology. In the design of retaining walls foundation mat and piles are considered as independent elements. Since the combined effect of the retaining wall, piles and foundation mat as well as the effect of soil or rock foundation on the structure are considered not fully, so there are some limitations in the existing design techniques. To achieve the purpose the box tests of retaining walls models without piles and with piles for studying their interaction with the surrounding soil massif were conducted. Findings. Laboratory simulation of complex systems «surrounding soil – retaining wall – pile» was carried out and on the basis of the box test results were analyzed strains and its main parameters of the stress-strain state. Analysis of the results showed that the structure of a retaining wall with piles is steady and stable. Originality. So far, in Ukraine has not been carried out similar experimental box tests with models of retaining walls in such combinations. In the article has been presented unique photos and test results, as well as their analysis. Practical value. Using the methodology of experimental tests of the retaining wall models with piles and without them gives a wider opportunity to study stress-strain state of such structures.

Comparative study of engineering properties of two-lime waste tire particle soil and soil with lime/loess ratio of 3:7

Science.gov (United States)

Tiecheng, Yan; Xingyuan, Zhang; Hongping, Yang

2018-03-01

This study describes an analytical comparison of the engineering characteristics of two-lime waste tire particle soil and soil with lime/loess ratio of 3:7 using density measurements, results of indoor consolidation tests, and direct shear tests to examine the strength and deformation characteristics. It investigates the engineering performance of collapsible loess treated with waste tire particles and lime. The results indicate that (1) the shear strength of the two-lime waste tire particle soils increases continuously with soil age; and (2) the two-lime waste tire particle soils are light-weight, strong, and low-deformation soils, and can be applied primarily to improve the foundation soil conditions in areas with collapsible loess soils. This could address the problem of used tire disposal, while providing a new method to consider and manage collapsible loess soils.

HSC Foundation

Science.gov (United States)

... in disability information or services and that add value to our existing programs. The Foundation also works to bring additional support to initiatives by serving as funding partners on projects that have local impact and national relevance. Supporting a Continuum of Care The HSC Foundation ...

Exact Stiffness for Beams on Kerr-Type Foundation: The Virtual Force Approach

Directory of Open Access Journals (Sweden)

Suchart Limkatanyu

2013-01-01

Full Text Available This paper alternatively derives the exact element stiffness equation for a beam on Kerr-type foundation. The shear coupling between the individual Winkler-spring components and the peripheral discontinuity at the boundaries between the loaded and the unloaded soil surfaces are taken into account in this proposed model. The element flexibility matrix is derived based on the virtual force principle and forms the core of the exact element stiffness matrix. The sixth-order governing differential compatibility of the problem is revealed using the virtual force principle and solved analytically to obtain the exact force interpolation functions. The matrix virtual force equation is employed to obtain the exact element flexibility matrix based on the exact force interpolation functions. The so-called “natural” element stiffness matrix is obtained by inverting the exact element flexibility matrix. One numerical example is utilized to confirm the accuracy and the efficiency of the proposed beam element on Kerr-type foundation and to show a more realistic distribution of interactive foundation force.

A load-displacement based approach to assess the bearing capacity and deformations of mono-bucket foundations

DEFF Research Database (Denmark)

Vahdatirad, Mohammadjavad; Diaz, Alberto Troya; Nielsen, Søren

2016-01-01

It is now accepted that a larger effort must be made in order to optimize the design so that offshore wind turbines can be competitive with the other energy resources. In this regard, mono-buckets are known as a cost-effective offshore foundation solution. In the current study, a load–displacemen......It is now accepted that a larger effort must be made in order to optimize the design so that offshore wind turbines can be competitive with the other energy resources. In this regard, mono-buckets are known as a cost-effective offshore foundation solution. In the current study, a load...... and run the calculations is proposed. The model is validated, and its accuracy is analyzed, by comparison with field test results for a bucket foundation installed in silty, sandy soil....

Influence of facing vertical stiffness on reinforced soil wall design

OpenAIRE

Puig Damians, Ivan; Bathurst, Richard; Josa Garcia-Tornel, Alejandro; Lloret Morancho, Antonio

2013-01-01

Current design practices for reinforced soil walls typically ignore the influence of facing type and foundation compressibility on the magnitude and distribution of reinforcement loads in steel reinforced soil walls under operational conditions. In this paper, the effect of the facing vertical stiffness (due to elastomeric bearing pads placed in the horizontal joints between panels) on load capacity of steel reinforced soil walls is examined in a systematic manner using a numerical modelli...

Numerical Study on Dynamic Response of Pile Group Foundation of Geotechnical Centrifuge

Directory of Open Access Journals (Sweden)

Mao Quansheng

2015-01-01

Full Text Available Based on National Engineering Laboratory for Harbor Engineering Structure-Geotechnical Centrifuge Laboratory construction project, the dynamical response of piles foundation under horizontal-rocking vibration was analyzed by using finite element software Abaqus, and the displacement and stress characteristics of piles were discussed with soil between the piles reinforced by high pressure jet piles. The result indicates that in the operation of the centrifuge, foundation changes of vertical load of center pile are very small; the vertical displacement of the pile head is increasing, the vertical displacement of the pile head is no longer changed until the vibration time reaches 3 times period,; the horizontal load of piles varies with sinusoidal, the horizontal displacement amplitude is increasing, , and the vibration amplitude reaches to fixed value at 2 times vibration period.

Buckling of Monopod Bucket Foundations – Influence of Boundary Conditions and Soil-structure Interaction

DEFF Research Database (Denmark)

Madsen, Søren; Pinna, Rodney; Randolph, M. F.

2015-01-01

of large-diameter bucket foundations. Since shell structures are generally sensitive to initially imperfect geometries, eigenmode-affine imperfections are introduced in a nonlinear finite-element analysis. The influence of modelling the real lid structure compared to classic boundary conditions...

Degree of saturation effect on the grout-soil interface shear strength of soil nailing

Directory of Open Access Journals (Sweden)

Wang Qiong

2016-01-01

Full Text Available In the grouted soil nailing system, the bonding strength of cement grout-soil interface offers the required resistance to maintain the stability of whole structure. In practice, soil nailing applications are often placed at unsaturated conditions, such as soil slopes, shallow foundations, retaining walls and pavement structures. In these cases, the water content in the soil nail zone may increase or decrease due to rain water or dry weather, and even cannot become saturated during their design service life. In this study, the effect of water content (degree of saturation on the shear strength of interface between cement grout and sand are experimentally investigated by means of direct shear test. Meanwhile the water retention curve was determined and interface microstructure was observed. Experimental results show that the shear strength of interface changes non-monotonously with degree of saturation when the interface was prepared, due to the non-monotonousness of the cohesiveness between soil particles. The less the cohesiveness between sand particles, the more grout was observed been penetrated into the voids, and thus the larger the interface shear stress.

1 INVESTIGATIONS ON THE EXPANSIVE SOILS OF ADDIS ABABA ...

African Journals Online (AJOL)

to owners for repair, if the structure is to be salvaged at all. The object of this paper is to study the significant engineering properties of the expans- ive soils and assess the damages on structures as a result of heaving and shrinkage of the soil on which the foundations of the structures are erected. For this purpose samples ...

Soil investigations for jack-ups, pile design, and fixed platforms

Energy Technology Data Exchange (ETDEWEB)

Krause, E R

1977-05-01

With the exception of dynamically positioned vessels, all stationary structures used by the petroleum industry in the sea are, in one way or another, connected to the seabed to ensure their immobility or stability. Consequently, the ability of the marine soils to support the imposed loads must be determined to allow a safe and economic foundation design and method of structure installation. Two main types of tests are being carried out offshore more or less on a routine basis: the cone penetration and the in-situ vane. The standard cone penetrometer testing method consists essentially of an electric penetrometer which is pushed into the seabed at a constant speed by an hydraulic piston. Remotely operated from the sea surface, the cone penetrates into the ground and the resistance that the soil exerts against the tip and sides of the cone are separately and continuously measured and recorded. The resulting continuous graph provides a detailed picture of the soil profile. In addition, soils data currently required for foundation design and installation can be derived from the test results based on existing correlations.

Determination, by using GPR, of the volumetric water content in structures, sub-structures, foundations and soil - ongoing activities in Working Project 2.5 of COST Action TU1208

Science.gov (United States)

Tosti, Fabio; Slob, Evert

2015-04-01

This work will endeavour to review the current status of research activities carried out in Working Project 2.5 'Determination, by using GPR, of the volumetric water content in structures, sub-structures, foundations and soil' within the framework of Working Group 2 'GPR surveying of pavements, bridges, tunnels and buildings; underground utility and void sensing' of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar' (www.GPRadar.eu). Overall, the Project includes 55 Participants from over 21 countries representing 33 Institutions. By considering the type of Institution, a percentage of 64% (35 units) comes from the academic world, while Research Centres and Companies include, respectively, the 27% (15 units) and 9% (5 units) of Institutions. Geographically speaking, Europe is the continent most represented with 18 out of 21 countries, followed by Africa (2 countries) and Asia (1 country). In more details and according to the Europe sub-regions classification provided by the United Nations, Southern Europe includes 39% of countries, Western Europe 27%, while Northern and Eastern Europe are equally present with 17% of countries each. Relying on the main purpose of Working Project 2.5, namely, the ground-penetrating radar-based evaluation of volumetric water content in structures, substructures , foundations, and soils, four main issues have been overall addressed over the first two years of activities. The first one, has been related to provide a comprehensive state of the art on the topic, due to the wide-ranging applications covered in the main disciplines of civil engineering, differently demanding. In this regard, two main publications reviewing the state of the art have been produced [1,2]. Secondly, discussions among Working Group Chairs and other Working Project Leaders have been undertaken and encouraged to avoid the risk of overlapping amongst similar topics from other Working

Soil-structure interaction effects in seismic analysis of turbine generator building on rock-like foundation

International Nuclear Information System (INIS)

Park, Chi Seon; Lee, Sang Hoon; Yoo, Kwang Hoon

2004-01-01

Soil properties supporting structure may become criteria determining methodologies for seismic response analysis of a structure. Regulatory Guide describes that a fixed-base assumption is acceptable for structures supported on rock or rock-like materials defined by a shear wave velocity of 3,500 ft/sec or greater at a shear strain of 10 -3 percent or smaller when considering preloaded soil conditions due to the structure. Seismic analyses for the Korean nuclear power plant (NPP) structures satisfying the above site soil condition have been completed through the fixed-base analysis. However, dynamic responses for relatively stiff structures such as NPP structures still have soil-structure interaction (SSI) effects. In other words, the fixed-base analysis does not always yield conservative results to be compared with SSI analysis. The SSI effects due to different stiff soil properties for Turbine Generator Building (TGB) structure to be constructed at Kori site of South Korea are investigated in views of floor response spectra (FRS) and member forces

Soil Architecture and physicochemical functions

DEFF Research Database (Denmark)

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

2012-01-01

, and modeling of soil structure (architecture) and physical, chemical, and biological processes in different porous media systems and at different scales. Several studies in this special section also outline and discuss emerging and exciting interdisciplinary challenges for the rapidly growing vadose zone......Soils function as Earth's life support system, a thin layer full of life covering most of the terrestrial surfaces. Soils form the foundation of society. Norman Borlaug stated in his Nobel laureate lecture that “the first essential component of social justice is adequate food for all mankind.......” If we are to provide this component while sustaining environmental quality in the midst of a growing population and rapidly diminishing resources, it is imperative to study and obtain a deeper level of understanding of soil functions using state-of-the-art technologies as well as provide the next...

Practice makes perfect: participatory innovation in soil fertility management to improve rural livelihoods in East Africa

OpenAIRE

Jager, de, A.

2007-01-01

Keywords: soil nutrient balances, soil fertility degradation, East Africa , participatory innovation, experiential learning, farmer field schools, smallholder agriculture Maintaining and improving soil fertility is crucial for Africa to attain the Millennium Development Goals. Fertile soil and balanced soil nutrient management are major foundations for sustainable food production, contribute to a sound management of natural resources and assist in controlling environmental degradation such ...

Geotechnical properties of marine soil off north Konkan Coast

Digital Repository Service at National Institute of Oceanography (India)

Ilangovan, D.; Jayakumar, S.; Naik, R.L.

Construction of any coastal structure requires detailed investigations on the environmental parameters as well as on the foundation soil. Preliminary geotechnicla investigations on the seabed sediment leads to a qualitative representation...

Comparing of Normal Stress Distribution in Static and Dynamic Soil-Structure Interaction Analyses

International Nuclear Information System (INIS)

Kholdebarin, Alireza; Massumi, Ali; Davoodi, Mohammad; Tabatabaiefar, Hamid Reza

2008-01-01

It is important to consider the vertical component of earthquake loading and inertia force in soil-structure interaction analyses. In most circumstances, design engineers are primarily concerned about the analysis of behavior of foundations subjected to earthquake-induced forces transmitted from the bedrock. In this research, a single rigid foundation with designated geometrical parameters located on sandy-clay soil has been modeled in FLAC software with Finite Different Method and subjected to three different vertical components of earthquake records. In these cases, it is important to evaluate effect of footing on underlying soil and to consider normal stress in soil with and without footing. The distribution of normal stress under the footing in static and dynamic states has been studied and compared. This Comparison indicated that, increasing in normal stress under the footing caused by vertical component of ground excitations, has decreased dynamic vertical settlement in comparison with static state

Shells on elastic foundations

International Nuclear Information System (INIS)

Das, Y.C.; Kedia, K.K.

1977-01-01

No realistic analytical work in the area of Shells on Elastic Foundations has been reported in the literature. Various foundation models have been proposed by several authors. These models involve one or more than one parameters to characterise the foundation medium. Some of these models cannot be used to derive the basic equations governing the behaviour of shells on elastic foundations. In the present work, starting from an elastic continuum hypothesis, a mathematical model for foundation has been derived in curvilinear orthogonal coordinates by the help of principle of virtual displacements, treating one of the virtual displacements as known to satisfy certain given conditions at its edge surfaces. In this model, several foundation parameters can be considered and it can also be used for layered medium of both finite and infinite thickness. (Auth.)

Approximate soil-structure interaction with separation of base mat from soil (lifting-off)

International Nuclear Information System (INIS)

Wolf, J.P.

1975-01-01

In reactor buildings having a sheild-building (outer concrete shell) with a large mass, which is particularly the case if the plant is designed for airplane crash, large over-turning moments are developed by earthquake loading. In this paper, the standard linear elastic half-space theory is used in the soil-structure interaction model. For a circular base mat, if the overturning moment exceeds the product of the normal force (dead weight minus the effect of the vertical earthquake) and one-third of the radius, then tension will occur in the area of contact, assuming distribution of stress as in the static case. For a strip foundation the same occurs if the eccentricity of the normal force exceeds a quarter of the total width. As tension is incompatible with the constitutive law of soils, the base mat will become partially separated from the foundation. Assming that only normal stresses in compression and corresponding shear stresses (friction) can occur in the area of contact, a method of analyzing soil-structure interaction including lifting-off is derived, which otherwise is based on elastic behaviour of the soil. First a rigorous iterative procedure is outlined based on (complex) dynamic influence matrices of displacements on the surface of an elastic half-space at a certain distance from a rigid disc or strip. A similar, approximate method is then developed which is used throughout the paper. As an example the dynamic response of the reactor building of a 1000 Megawatt plant to earthquake motion is calculated. The results of the analysis, including lift-off, are compared to those of the linear case. (Auth.)

Evaluation of seismic behavior of soils under nuclear containment structures via dynamic centrifuge test

Energy Technology Data Exchange (ETDEWEB)

Ha, Jeong Gon, E-mail: jgha87@kaist.ac.kr; Kim, Dong-Soo, E-mail: dskim@kaist.ac.kr

2014-10-01

Highlights: • A series of dynamic centrifuge tests were performed for NPP structure to investigate the soil–foundation-structure interaction with various soil conditions from loose sand to weathered rock. • SFSI phenomena for NPP structure were observed directly using experimental method. • Effect of the soil stiffness and nonlinear characteristics on SFSI was estimated. • There are comparisons of the control motions for seismic design of a NPP structure. • Subsoil condition, earthquake intensity and control motion affected to seismic load. - Abstract: To evaluate the earthquake loads for the seismic design of a nuclear containment structure, it is necessary to consider the soil–foundation-structure interaction (SFSI) due to their interdependent behavior. Especially, understanding the effects of soil stiffness under the structure and the location of control motion to SFSI are very important. Motivated by these requirements, a series of dynamic centrifuge tests were performed with various soil conditions from loose sand to weathered rock (WR), as well as different seismic intensities for the bedrock motion. The different amplification characteristics in peak-accelerations profile and effects of soil-nonlinearity in response spectrum were observed. The dynamic behaviors were compared between surface of free-field and foundation of the structure for the evaluation of the control motion for seismic design. It was found that dynamic centrifuge test has potentials to estimate the seismic load considering SFSI.

Evaluation of seismic behavior of soils under nuclear containment structures via dynamic centrifuge test

International Nuclear Information System (INIS)

Ha, Jeong Gon; Kim, Dong-Soo

2014-01-01

Highlights: • A series of dynamic centrifuge tests were performed for NPP structure to investigate the soil–foundation-structure interaction with various soil conditions from loose sand to weathered rock. • SFSI phenomena for NPP structure were observed directly using experimental method. • Effect of the soil stiffness and nonlinear characteristics on SFSI was estimated. • There are comparisons of the control motions for seismic design of a NPP structure. • Subsoil condition, earthquake intensity and control motion affected to seismic load. - Abstract: To evaluate the earthquake loads for the seismic design of a nuclear containment structure, it is necessary to consider the soil–foundation-structure interaction (SFSI) due to their interdependent behavior. Especially, understanding the effects of soil stiffness under the structure and the location of control motion to SFSI are very important. Motivated by these requirements, a series of dynamic centrifuge tests were performed with various soil conditions from loose sand to weathered rock (WR), as well as different seismic intensities for the bedrock motion. The different amplification characteristics in peak-accelerations profile and effects of soil-nonlinearity in response spectrum were observed. The dynamic behaviors were compared between surface of free-field and foundation of the structure for the evaluation of the control motion for seismic design. It was found that dynamic centrifuge test has potentials to estimate the seismic load considering SFSI

Assessing the small-strain soil stiffness for offshore wind turbines based on in situ seismic measurements

NARCIS (Netherlands)

Versteijlen, W.G.; Van Dalen, K.N.; Metrikine, A.; Hamre, L.

2014-01-01

In this contribution, in situ seismic measurements are used to derive the small-strain shear modulus of soil as input for two soil-structure interaction (SSI) models to assess the initial soil stiffness for offshore wind turbine foundations. This stiffness has a defining influence on the first

Mesothelioma Applied Research Foundation

Science.gov (United States)

... Foundation Experts Can Answer Your Questions! The Mesothelioma Applied Research Foundation's team of experts is available to answer ... a law firm. Read more about the Mesothelioma Applied Research Foundation . TO GET HELP CALL: (877) End-Meso ...

A foundation for foundation phase teacher education: Making wise educational judgements

Directory of Open Access Journals (Sweden)

Karin Murris

2014-12-01

Full Text Available We start our paper with a critical exploration of the current ‘back to basics’ approach in South African foundation phase teacher education with its emphasis on strengthening the teaching of subject knowledge. We claim that such a proposal first demands an answer to the question ‘what is foundational in foundation phase teaching?’ We propose an answer in three stages. First we argue that teacher education should be concerned not only with schooling or qualification (knowledge, skills and dispositions and socialisation, but, drawing on Gert Biesta’s work, also with subjectification (educating the person towards the ability to make wise educational judgements. Secondly, these three aims of education lead to five core principles, and we finish by showing how these principles inform our storied, thinking and multimodal/semiotic curriculum. Our answer to our leading question is that pedagogical ‘know-how’ and views of ‘child’ and ‘childhood’ constitute the subject knowledge that is foundational in the foundation phase curriculum.

Effects of a thin liquefiable foundation layer on deformations of a rockfill dam subjected to earthquake shaking

Energy Technology Data Exchange (ETDEWEB)

Seid-Karbasi, M.; Atukorala, U. [Golder Associates Ltd., Burnaby, BC (Canada); Gowan, M.; Barrett, A. [Golder Associates Pty, Toowong, Queensland (Australia)

2008-07-01

This paper discussed a coupled stress-flow dynamic analysis procedure designed to predict the stability and seismic deformations of an 85 meter high earth dam located near a polymetallic mine in Vietnam. The procedure was developed to capture sand element behaviours observed in previous laboratory tests. The analysis was conducted using a UBCSAND model to capture the liquefiable soil response. Nonlinear behaviour of the non-liquefiable materials was modelled using the UBCHYST simulation tool. Both models were incorporated within the FLAC model. Dam specifications, foundation characteristics, and predicted behaviours were discussed. The dam body and its foundation were analyzed under gravity loads with drained conditions in order to establish the pre-earthquake stress state. A dynamic analysis was then conducted using undrained properties for fine-grained soils. The FLAC model finite difference analysis was used to examine stress-flow under static and dynamic loading conditions. Earthquake motions were applied as a time history of excitation at the model's boundaries. Volumetric strains were controlled by the compressibility of the pore fluid and the flow of water through the soil elements. The model was calibrated using laboratory and centrifuge data. Results of the study showed that the tailings and downstream free-field alluvial soils developed high excess pore water pressures and liquefied during strong shaking motions. Results suggested that the seismic performance of the Oxide dam were satisfactory. 41 refs., 1 tab., 7 figs.

A probabilistic analysis of the dynamic response of monopile foundations: Soil variability and its consequences

DEFF Research Database (Denmark)

Damgaard, M.; Andersen, L.V.; Ibsen, L.B.

2015-01-01

The reliability of offshore wind turbines is highly influenced by the uncertainties related to the subsoil conditions. Traditionally, the evaluation of the dynamic structural behaviour is based on a computational model with deterministic soil properties. Using this approach, however, provides...... on a Monte Carlo method facilitating the derivation of the probability densities of the modal properties and the fatigue loading. The main conclusion of the presented work is that the dynamic structural behaviour of the wind turbine and its support structure is strongly affected by the stochastic soil......-analytical impedance functions of a monopile embedded in a stochastic linear viscoelastic soil layer, fully coupled aero-hydro-elastic simulations are conducted in the nonlinear multi-body code Hawc2. The probabilistic analysis accounts for the uncertainty of soil properties (e.g. damping and stiffness) and relies...

Foundations for renewables

Energy Technology Data Exchange (ETDEWEB)

Neidlein, H.C. [German Agency Scherer Schnell Walser und Partner (Germany)

2007-07-01

In Germany, 77 foundations promote renewable energy technology with around Euro 25 million annually. The most important internationally active foundations, however, can be found in the Anglo-Saxon countries. (orig.)

Studies on Pounding Response Considering Structure-Soil-Structure Interaction under Seismic Loads

Directory of Open Access Journals (Sweden)

Peizhen Li

2017-12-01

Full Text Available Pounding phenomena considering structure–soil–structure interaction (SSSI under seismic loads are investigated in this paper. Based on a practical engineering project, this work presents a three-dimensional finite element numerical simulation method using ANSYS software. According to Chinese design code, the models of adjacent shear wall structures on Shanghai soft soil with the rigid foundation, box foundation and pile foundation are built respectively. In the simulation, the Davidenkov model of the soil skeleton curve is assumed for soil behavior, and the contact elements with Kelvin model are adopted to simulate pounding phenomena between adjacent structures. Finally, the dynamic responses of adjacent structures considering the pounding and SSSI effects are analyzed. The results show that pounding phenomena may occur, indicating that the seismic separation requirement for adjacent buildings of Chinese design code may not be enough to avoid pounding effect. Pounding and SSSI effects worsen the adjacent buildings’ conditions because their acceleration and shear responses are amplified after pounding considering SSSI. These results are significant for studying the effect of pounding and SSSI phenomena on seismic responses of structures and national sustainable development, especially in earthquake prevention and disaster reduction.

Static Behaviour of Bucket Foundations

DEFF Research Database (Denmark)

Larsen, Kim André

One new foundation concept in relation to offshore wind turbines is bucket foundations. The concept is known from the oil and gas industry, though the load conditions here are significantly different. The bucket foundation can be used as monopod or e.g. tripod foundations for offshore wind turbines....... The monopod concept is investigated in this thesis, regarding the static behaviour from loads relevant to offshore wind turbines. The main issue in this concept is the rotational stiffness of the foundation and the combined capacity dominated by moments. The vertical bearing capacity of bucket foundations...... theory is proposed. The proposed expression applies to plane strain as well as axis-symmetric stress conditions for foundations with smooth or rough bases. A thorough experimental investigation of the static behaviour of bucket foundations subjected to combined loading is carried out. Laboratory tests...

Study on monitoring of deep foundation pit with SMW engineering method plus anchor cable retaining structure

Science.gov (United States)

Chen, Wenzhao; Cui, Wenping

2018-03-01

The SMW method has many advantages, such as little influence on the surrounding environment, good watertight performance, wide range of application, short construction period, low cost and so on. In this paper, we chose the SMW engineering method combined with anchor cable to support structure in the second phase deep foundation pit of Jinan LuJinDongCheng as the research object, monitored and analysed the horizontal displacement of the pile top, Peripheral surface subsidence and internal force of the anchor cable in the foundation pit. We also discussed the displacement, internal force of anchor cable and the settlement of surrounding environment in the excavation of foundation pit and in different stages of construction. Conclusion:(1)The maximum horizontal displacement of the retaining structure is closely related to the depth and time of excavation, the construction of anchor cable can well limit the deformation of pile body; (2)Groundwater seepage caused by foundation pit dewatering will change the effective stress of soil. The change of groundwater level has an important influence on the working behavior of smw anchor cable supporting structure.

PECULIAR FEATURES PERTAINING TO SOIL DEPOSIT FORMATION IN THE MESOPOTAMIA ZONE OF IRAQ

Directory of Open Access Journals (Sweden)

A. Al-Robai Ali

2013-01-01

Full Text Available The paper considers geological conditions for sedimentary mantle formation. In the geological past limestone deposits and sedimentation rock mass from fragmentary materials brought by water flows were formed in the southern part of the stretched geosyncline which had been submerged by shallow sea. By lapse of time deposits were transferred into sandstone, siltstone and mudstone that represented the bottom part of rock mass. Continental conditions were established as a result of orogenic process which took place nearly 30–50 million years ago. Erosional activity of wind and flowing waters was observed on the surface for a long period of time.The top part of soil rock mass is represented by alluvial deposits of the rivers Tigris and Euphrates. During the process of sediment deposition more full-flowing Tigris caused more complicated dynamics of water channels  including meandering and changeability of inter-bedding.Engineering and geological investigations have been carried out with the purpose to study structure of soil rock mass in various regions of the country (Al-Diwaniya, Khidr, Al-Nasiriya and Khila. Specific drill columns have been selected on the basis of analysis of soil rock masses.  Theses drill columns may serve for further selection of rational types of foundations (shallow foundation, piles foundation or creation of artificial foundations (cementing, armoring etc.. 

A short history of the soil science discipline

Science.gov (United States)

Brevik, E. C.; Hartemink, A. E.

2012-04-01

Since people have cultivated the land they have generated and created knowledge about its soil. By the 4th century most civilizations around had various levels of soil knowledge and that includes irrigation, the use of terraces to control soil erosion, methods to maintain and improve soil fertility. The early soil knowledge was largely empirical and based on observations. Many famous scientists, for example, Francis Bacon, Robert Boyle, Charles Darwin, and Leonardo da Vinci worked on soil issues. Soil science became a true science in the 19th century with the development of genetic soil science, lead by the Russian Vasilii V. Dokuchaev. In the beginning soil science had strong ties to both geology and agriculture but in the 20th century, soil science is now being applied in residential development, the planning of highways, building foundations, septic systems, wildlife management, environmental management, and many other applications. The discipline is maturing and soil science plays a crucial role in many of the current issues that confront the world like climate change, water scarcity, biodiversity and environmental degradation.

3D Bearing Capacity of Structured Cells Supported on Cohesive Soil: Simplified Analysis Method

Directory of Open Access Journals (Sweden)

Martínez-Galván Sergio Antonio

2013-06-01

Full Text Available In this paper a simplified analysis method to compute the bearing capacity of structured cell foundations subjected to vertical loading and supported in soft cohesive soil is proposed. A structured cell is comprised by a top concrete slab structurally connected to concrete external walls that enclose the natural soil. Contrary to a box foundation it does not include a bottom slab and hence, the soil within the walls becomes an important component of the structured cell. This simplified method considers the three-dimensional geometry of the cell, the undrained shear strength of cohesive soils and the existence of structural continuity between the top concrete slab and the surrounding walls, along the walls themselves and the walls structural joints. The method was developed from results of numerical-parametric analyses, from which it was found that structured cells fail according to a punching-type mechanism.

Toxicology Education Foundation

Science.gov (United States)

... bodies and our world. Welcome to the Toxicology Education Foundation! Our mission is to enhance public understanding ... In with us, follow our Tweets, choose Toxicology Education Foundation as your preferred charity through Smile.Amazon. ...

Skin Cancer Foundation

Science.gov (United States)

... Host a Fundraising Event | About Us | Store The Skin Cancer Foundation The Skin Cancer Foundation is the ... Handbook A "Sunscreen Gene"? Skin Cancer Facts & Statistics Skin Cancer Treatment Glossary Information on medications and procedures ...

Evaluation of scour potential of cohesive soils - phase 2.

Science.gov (United States)

2015-01-01

Determination of erosion parameters in order to predict scour depth is imperative to designing safe, : economic, and efficient bridge foundations. Scour behavior of granular soils is generally understood, : and design criteria have been established b...

Earthquake response analysis considering structure-soil-structure interaction

International Nuclear Information System (INIS)

Shiomi, T.; Takahashi, K.; Oguro, E.

1981-01-01

This paper proposes a numerical method of earthquake response analysis considering the structure-soil-structure interaction between two adjacent buildings. In this paper an analytical study is presented in order to show some typical features of coupling effects of two reactor buildings of the BWR-type nuclear power plant. The technical approach is a kind of substructure method, which at first evaluates the compliance properties with the foundation-soil-foundation interaction and then uses the compliance in determining seismic responses of two super-structures during earthquake motions. For this purpose, it is assumed that the soil medium is an elastic half space for modeling and that the rigidity of any type of structures such as piping facilities connecting the adjacent buildings is negligible. The technical approach is mainly based on the following procedures. Supersturcture stiffness is calculated by using the method which has been developed in our laboratory based on the Thin-Wall Beam Theory. Soil stiffness is expressed by a matrix with 12 x 12 elements as a function of frequency, which is calculated using the soil compliance functions proposed in Dr. Tajimi's Theory. These stiffness values may be expressed by complex numbers for modeling the damping mechanism of superstructures. We can solve eigenvalue problems with frequency dependent stiffness and the large-scale matrix using our method which is based on condensing the matrix to the suitable size by Rayleigh-Ritz method. Earthquake responses can be solved in the frequency domain by Fourier Transform. (orig./RW)

Feedback of the behaviour of a silo founded on a compressible soil improved by floating stone columns

Directory of Open Access Journals (Sweden)

Bahar Ramdane

2018-01-01

Full Text Available The coastal city of Bejaia, located 250 kilometers east of the capital Algiers, Algeria, is characterized by soft soils. The residual grounds encountered on the first 40 meters usually have a low bearing capacity, high compressibility, insufficient strength, and subject to the risk of liquefaction. These unfavorable soil conditions require deep foundations or soil improvement. Since late 1990s, stone columns technique is used to improve the weak soils of the harbor area of the city. A shallow raft foundation on soft soil improved by stone columns was designed for a heavy storage steel silo and two towers. The improvement of 18m depth have not reached the substratum located at 39m depth. The stresses transmitted to the service limit state are variable 73 to 376 kPa. A rigorous and ongoing monitoring of the evolution of loads in the silo and settlements of the soil was carried out during 1400 days that is from the construction of foundations in 2008 to 2012. After the loading of the silo in 2010, settlement occurred affecting the stability of the towers due to excessive differential settlements. Consequently, the towers were inclined and damaged the transporter. This paper presents and discusses the experience feedback of the behavior of these structures. Numerical calculations by finite elements have been carried and the results are compared with the measurements.

The Settlement Behavior of Piled Raft Interaction in Undrained Soil

DEFF Research Database (Denmark)

Ghalesari, Abbasali Taghavi; Barari, Amin; Amini, Pedram Fardad

2013-01-01

Offshore piled raft foundations are one of the most commonly used foundations in offshore structures. When a raft foundation alone does not satisfy the design requirements, the addition of piles may improve both the ultimate load capacity and the settlement performance of the raft. In this paper......, the behavior of a piled raft on undrained soil is studied based on a series of parametric studies on the average and differential settlement of piled raft using three-dimensional finite element analysis. The settlement behavior is found to be dependent on the number of piles and raft thickness....

Semi-analytical approach to modelling the dynamic behaviour of soil excited by embedded foundations

DEFF Research Database (Denmark)

Bucinskas, Paulius; Andersen, Lars Vabbersgaard

2017-01-01

The underlying soil has a significant effect on the dynamic behaviour of structures. The paper proposes a semi-analytical approach based on a Green’s function solution in frequency–wavenumber domain. The procedure allows calculating the dynamic stiffness for points on the soil surface as well...... are analysed. It is determined how simplification of the numerical model affects the overall dynamic behaviour. © 2017 The Authors. Published by Elsevier Ltd....

The Danish Industrial Foundations

DEFF Research Database (Denmark)

Thomsen, Steen

and governed, what role it plays in the Danish economy, and how industrial foundation-owned companies perform. The book is the result of a large collaborative research project, led by the author, on industrial foundations. Some global companies such as IKEA, Robert Bosch or the Tata Group are foundation...

Grouting for Pile Foundation Improvement

NARCIS (Netherlands)

Van der Stoel, A.E.C.

2001-01-01

The aim of this research was to examine the use of grouting methods for pile foundation improvement, a generic term that is used here to define both foundation renovation (increasing the bearing capacity of a pile foundation that has insufficient bearing capacity) and foundation protection

A foundation for foundation phase teacher education: Making wise educational judgements

OpenAIRE

Karin Murris; Clare Verbeek

2014-01-01

We start our paper with a critical exploration of the current ‘back to basics’ approach in South African foundation phase teacher education with its emphasis on strengthening the teaching of subject knowledge. We claim that such a proposal first demands an answer to the question ‘what is foundational in foundation phase teaching?’ We propose an answer in three stages. First we argue that teacher education should be concerned not only with schooling or qualification (knowledge, skills and disp...

Lower-Bound Calculations of the Bearing Capacity of Eccentrically Loaded Footings in Cohesionless Soil

DEFF Research Database (Denmark)

Krabbenhøft, Sven; Damkilde, Lars; Krabbenhøft, Kristian

2012-01-01

Lower-bound calculations based on the finite element method are used to determine the bearing capacity of a strip foundation subjected to a vertical, eccentric load on cohesionless soil with varying surcharges. The soil is assumed perfectly plastic following the Mohr-Coulomb failure criterion. Th...

Education in Soil Science: the Italian approach

Science.gov (United States)

Benedetti, Anna; Canfora, Loredana; Dazzi, Carmelo; Lo Papa, Giuseppe

2017-04-01

The Italian Society of Soil Science (SISS) was founded in Florence on February 18th, 1952. It is an association legally acknowledged by Decree of the President of the Italian Republic in February 1957. The Society is member of the International Union of Soil Sciences (IUSS) of the European Confederation of Soil Science Societies (ECSSS) and collaborates with several companies, institutions and organizations having similar objectives or policy aspects. SISS promotes progress, coordination and dissemination of soil science and its applications encouraging relationships and collaborations among soil lovers. Within the SISS there are Working Groups and Technical Committees for specific issues of interest. In particular: • the Working Group on Pedotechniques; • the Working Group on Hydromorphic and Subaqueous Soils and • the Technical Committee for Soil Education and Public Awareness. In this communication we wish to stress the activities developed since its foundation by SISS to spread soil awareness and education in Italy through this last Technical Committee, focusing also the aspect concerning grants for young graduates and PhD graduates to stimulate the involvement of young people in the field of soil science. Keywords: SISS, soil education and awareness.

Solar panel foundation device

Energy Technology Data Exchange (ETDEWEB)

Hawley, W.W.

1983-03-29

A transportable solar panel foundation device which has a bottom member, at least one upstanding side member, and an essentially open top. The side members are angled to permit nesting of a plurality of the foundation devices, and reinforcement pads are carried by the foundation device to support legs for one or more solar panels.

The impact of foundation conditions on the design and construction of the Snake Lake Reservoir dams

International Nuclear Information System (INIS)

Griffin, G. D.

1998-01-01

Unique aspects of the design and construction of two small dams for the Snake Lake Reservoir Project and some of the lessons learned in the process are described. The outstanding feature of this project was that although relatively close together and in the same post-glacial channel, the foundations of the two dams were quite different. The West Dam had permeable silt, sand and gravel with deep bedrock, while the East Dam had impermeable high plastic clay and shallow bedrock as foundation. The challenge to the design was to develop a cross section that would work for both foundation conditions. The final design turned out to be an impermeable fill with toe berms accommodating the variability in the foundations. Instrumentation was used to determine when the second construction stage should commence. At the end of the construction, the reservoir was partially filled relying on the instrumentation to suggest when that would be safe enough to proceed without impacting the overall embankment stability. In the event, the West Dam foundation soils proved to be several orders of magnitude higher than estimated from grain size analyses, requiring installation of a relief valve after construction was completed. Apart from that, dam construction proceeded smoothly and the instrumentation performed as expected.12 refs., 7 figs

Soil Security Assessment of Tasmania

Science.gov (United States)

Field, Damien; Kidd, Darren; McBratney, Alex

2017-04-01

The concept of soil security aligns well with the aspirational and marketing policies of the Tasmanian Government, where increased agricultural expansion through new irrigation schemes and multiple-use State managed production forests co-exists beside pristine World Heritage conservation land, a major drawcard of the economically important tourism industry . Regarding the Sustainable Development Gaols (SDG's) this could be seen as a exemplar of the emerging tool for quantification of spatial soil security to effectively protect our soil resource in terms of food (SDG 2.4, 3.9) and water security (SDG 6.4, 6.6), biodiversity maintenance and safeguarding fragile ecosystems (SDG 15.3, 15.9). The recent development and application of Digital Soil Mapping and Assessment capacities in Tasmania to stimulate agricultural production and better target appropriate soil resources has formed the foundational systems that can enable the first efforts in quantifying and mapping Tasmanian Soil Security, in particular the five Soil Security dimensions (Capability, Condition, Capital, Codification and Connectivity). However, to provide a measure of overall soil security, it was necessary to separately assess the State's three major soil uses; Agriculture, Conservation and Forestry. These products will provide an indication of where different activities are sustainable or at risk, where more soil data is needed, and provide a tool to better plan for a State requiring optimal food and fibre production, without depleting its natural soil resources and impacting on the fragile ecosystems supporting environmental benefits and the tourism industry.

Calculation methods of Structure-Soil-Structure Interaction (3SI) for embedded buildings: Application to NUPEC tests

International Nuclear Information System (INIS)

Clouteau, D.; Broc, D.; Devesa, G.; Guyonvarh, V.; Massin, P.

2012-01-01

This work aims at improving and validating methods coupling Finite Element (FE) and Boundary Element (BE) Methods in the context of Soil-Structure Interaction (SSI) and Structure-Soil-Structure Interaction (3SI) tests performed by NUPEC on mock-up structures built on an unmade ground. Several cases have been tested: single and juxtaposed buildings, shallow and embedded foundations, with various loading conditions: forced and natural seismic loadings. The numerical simulations of forced vibration tests are in good agreement with the results of the NUPEC experiments in the case of two embedded buildings either in terms of amplitude and resonance. The numerical simulation of seismic response tests by FEM and BEM allows for a proper choice of the 'reference point' where the computed and the experimental displacements coincide. A parametric analysis of Structure-Soil-Structure Interaction carried out by the FEM has allowed to determine the influence of some parameters on SSI. Most of them like the position of the building in the excavation, the direction of the load, the quality of the contact between the sidewalls of the buildings and the soil for embedded foundations, do not show to have a strong influence on the dynamic system behaviour, which is mainly governed by the stiffness of the first soil layer. As far as 3SI is concerned, this paper shows that when the cross interaction has a small effect on the building response in the case of surface foundations, it has a strong influence in the case of embedded foundations with an important decrease of the response at the top of the buildings. (authors)

Model test on partial expansion in stratified subsidence during foundation pit dewatering

Science.gov (United States)

Wang, Jianxiu; Deng, Yansheng; Ma, Ruiqiang; Liu, Xiaotian; Guo, Qingfeng; Liu, Shaoli; Shao, Yule; Wu, Linbo; Zhou, Jie; Yang, Tianliang; Wang, Hanmei; Huang, Xinlei

2018-02-01

Partial expansion was observed in stratified subsidence during foundation pit dewatering. However, the phenomenon was suspected to be an error because the compression of layers is known to occur when subsidence occurs. A slice of the subsidence cone induced by drawdown was selected as the prototype. Model tests were performed to investigate the phenomenon. The underlying confined aquifer was generated as a movable rigid plate with a hinge at one end. The overlying layers were simulated with remolded materials collected from a construction site. Model tests performed under the conceptual model indicated that partial expansion occurred in stratified settlements under coordination deformation and consolidation conditions. During foundation pit dewatering, rapid drawdown resulted in rapid subsidence in the dewatered confined aquifer. The rapidly subsiding confined aquifer top was the bottom deformation boundary of the overlying layers. Non-coordination deformation was observed at the top and bottom of the subsiding overlying layers. The subsidence of overlying layers was larger at the bottom than at the top. The layers expanded and became thicker. The phenomenon was verified using numerical simulation method based on finite difference method. Compared with numerical simulation results, the boundary effect of the physical tests was obvious in the observation point close to the movable endpoint. The tensile stress of the overlying soil layers induced by the underlying settlement of dewatered confined aquifer contributed to the expansion phenomenon. The partial expansion of overlying soil layers was defined as inversed rebound. The inversed rebound was induced by inversed coordination deformation. Compression was induced by the consolidation in the overlying soil layers because of drainage. Partial expansion occurred when the expansion exceeded the compression. Considering the inversed rebound, traditional layer-wise summation method for calculating subsidence should be

Shaking table test and analysis of embedded structure soil interaction considering input motion

International Nuclear Information System (INIS)

Matsushima, Y.; Mizuno, H.; Machida, N.; Sato, K.; Okano, H.

1987-01-01

The dynamic interaction between soil and structure is decomposed into inertial interaction (II) and kinematic interaction (KI). II denotes the interaction due to inertial force applied on foundations. KI denotes the interaction of massless foundations subjected to seismic waves. Forced vibration tests by exciters are not enough to evaluate the complete soil-structure interaction due to the lack of KI. To clarify the effects of KI on the seismic response of structure, the authors intended to carry out shaking table tests of the interaction between the soil and the embedded structure. A method to decompose II and KI is introduced which reveals the construction of embedment effects. Finally, the authors discuss the validity of three kinds of simulation analyses, that is, two-dimensional, approximate three-dimensional and rigorous three-dimensional analyses, comparing with the test results

Analysis on soil compressibility changes of samples stabilized with lime

Directory of Open Access Journals (Sweden)

Elena-Andreea CALARASU

2016-12-01

Full Text Available In order to manage and control the stability of buildings located on difficult foundation soils, several techniques of soil stabilization were developed and applied worldwide. Taking into account the major significance of soil compressibility on construction durability and safety, the soil stabilization with a binder like lime is considered one of the most used and traditional methods. The present paper aims to assess the effect of lime content on soil geotechnical parameters, especially on compressibility ones, based on laboratory experimental tests, for several soil categories in admixture with different lime dosages. The results of this study indicate a significant improvement of stabilized soil parameters, such as compressibility and plasticity, in comparison with natural samples. The effect of lime stabilization is related to an increase of soil structure stability by increasing the bearing capacity.

Forward the Foundation: Local Education Foundations Offer an Alternative Source for School Funding

Science.gov (United States)

Brooks-Young, Susan

2007-01-01

February's column "Going Corporate" discussed ideas for approaching private foundations for funding. Some districts take this idea several steps further by partnering with the community and local businesses to establish a not-for-profit foundation, or local education foundation (LEF). It probably comes as no surprise that the idea of forming a LEF…

Behaviour of Soil Subjected to Dynamic Loads

DEFF Research Database (Denmark)

Bødker, L.

1998-01-01

foundations, and hence it is necessary to know the deformation properties for the soil at very low strain level. The main topic of the project is to increase the knowledge of the behaviour of Danish soils at small strain levels and to extend the laboratory facilities to deal with testing at small strains....... The soil behaviour at very small strain levels is non-linear, and the most common testing technique for this situation is the resonant column technique. One of the aims of this project is to install, check, get familiar with and perform tests on different kinds of Danish soils in a new Drnevich...... Longitudinal-Torsional Resonant Column apparatus placed at the Soil Mechanics Laboratory at Aalborg University. Another, but quite new technique for small strain testing to determine the maximum shear modulus, Gmax, is the bender element technique, and as part of the project this technique has also been...

Applications in soil-structure interactions. Final report, June 1979

International Nuclear Information System (INIS)

Jhaveri, D.P.

1979-01-01

Complex phenomenon of soil-structure interaction was assessed. Relationships between the characteristics of the earthquake ground motions, the local soil and geologic conditions, and the response of the structures to the ground motions were studied. (I) The use of the explicit finite-difference method to study linear elastic soil-structure interaction is described. A linear two-dimensional study of different conditions that influence the dynamic compliance and scattering properties of foundations is presented. (II) The FLUSH computer code was used to compute the soil-structure interaction during SIMQUAKE 1B, an experimental underground blast excitation of a 1/12-scale model of a nuclear containment structure. Evaluation was performed using transient excitation, applied to a finite-difference grid. Dynamic foundation properties were studied. Results indicate that the orientation and location of the source relative to the site and the wave environment at the site may be important parameters to be considered. Differences between the computed and experimental recorded responses are indicated, and reasons for the discrepancy are suggested. (III) A case study that examined structural and ground response data tabulated and catalogued from tests at the Nevada Test Site for its applicability to the soil-structure interaction questions of interest is presented. Description, methods, and evaluation of data on soil-structure interaction from forced vibration tests are presented. A two-dimensional finite-difference grid representing a relatively rigid structure resting on uniform ground was analyzed and monitored. Fourier spectra of monitored time histories were also evaluated and are presented. Results show clear evidence of soil-structure interaction and significant agreement with theory. 128 figures, 18 tables

Can Innate, modular "foundations" explain morality? Challenges for Haidt's Moral Foundations Theory.

Science.gov (United States)

Suhler, Christopher L; Churchland, Patricia

2011-09-01

Jonathan Haidt's Moral Foundations Theory is an influential scientific account of morality incorporating psychological, developmental, and evolutionary perspectives. The theory proposes that morality is built upon five innate "foundations," each of which is believed to have been selected for during human evolution and, subsequently, tuned-up by learning during development. We argue here that although some general elements of Haidt's theory are plausible, many other important aspects of his account are seriously flawed. First, innateness and modularity figure centrally in Haidt's account, but terminological and conceptual problems foster confusion and ambiguities. Second, both the theory's proposed number of moral foundations and its taxonomy of the moral domain appear contrived, ignoring equally good candidate foundations and the possibility of substantial intergroup differences in the foundations' contents. Third, the mechanisms (viz., modules) and categorical distinctions (viz., between foundations) proposed by the theory are not consilient with discoveries in contemporary neuroscience concerning the organization, functioning, and development of the brain. In light of these difficulties, we suggest that Haidt's theory is inadequate as a scientific account of morality. Nevertheless, the theory's weaknesses are instructive, and hence, criticism may be useful to psychologists, neuroscientists, and philosophers attempting to advance theories of morality, as well as to researchers wishing to invoke concepts such as innateness and modularity more generally.

Archaeological investigation by geotomography: structure of the foundation of Yingxian timber pagoda

Science.gov (United States)

Feng, Rui; Yan, Wei-Zhang; Feng, Guo-Zheng; Tao, Yu-Lu; Zhou, Hai-Nan; Li, Xiao-Qin

1998-03-01

It is significant to take a non-destructive inspection, one of advanced techniques, for detecting the internal structure and the present status of ancient cultural relics. The results detected by geotomography in Yingxian timber pagoda, Shanxi Province, are presented in this paper. The embankment in the stepped foundation shows a three circular structure in horizontal: the circular platform core is hard, homogenous and unharmed, out of which there are some radial collapsed grooves. The middle circle with a thickness of 2 to 4 m is a compacted layer and its loading capacity decreases then. The outer protective layer has a larger porosity and a weak loading capacity. An abnormal body is found out in the core, which has a circular shape and a reverse high-absorption coefficient in the shallow part, but appears a long-band shape and a low-absorption coefficient in the deep part. It might be a disturbance caused by artificial activities: the shallow part is probably a channel filled with loosen soil and the deep part is a hidden cave. It is found that the foundation of the courtyard is homogenous and integrated. Two soft and weakened areas in the north are related to the long-term run-off and drainage of groundwater. The inclination of the timber pagoda to the northwest and northeast relates to several factors, such as the inherited subsidence of the northern foundation, the lower loading capacity of the outer stepped foundation, seismic activity and timber deformation.

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

DEFF Research Database (Denmark)

Sørensen, Søren Peder Hyldal

conducted. The initial part of p-y curves for non-slender piles has been investigated by means of numerical modelling. The general behaviour of eccentrically loaded non-slender piles has been investigated by physical modelling. These tests have been conducted in the pressure tank at Aalborg University....... The monopile foundation concept has been employed as the foundation for the majority of the currently installed offshore wind turbines. Therefore, this PhD thesis concerns the soil-pile interaction for non-slender, large-diameter offshore piles. A combination of numerical and physical modelling has been....... Hence, the application of an overburden pressure is possible. The timescale of the backfill process and the compaction of soil material backfilled around piles in storm conditions have been investigated by means of large-scale physical modelling....

Radon-technical design methods based on radon classification of the soil

International Nuclear Information System (INIS)

Kettunen, A.V.

1993-01-01

Radon-technical classification of the foundation soil divides the foundation soil into four classes: negligible, normal, high and very high. Separate radon-technical designing methods and radon-technical solutions have been developed for each class. On regions of negligible class, no specific radon-technical designing methods are needed. On regions of normal radon class, there is no need for actual radon-technical designing based on calculations, whereas existing radon-technical solutions can be used. On regions of high and very high radon class, a separate radon-technical designing should be performed in each case, where radon-technical solutions are designed so that expected value for indoor radon content is lower than the maximum allowable radon content. (orig.). (3 refs., 2 figs., 2 tabs.)

The settlement of foundation of existing large structure on soft ground and investigation of its allowable settlement

International Nuclear Information System (INIS)

Okamoto, Toshiro

1987-01-01

In our laboratory a study of siting on quarternary ground is followed to make possible to construct a nuclear power plant on soil ground in Japan, a important subject is to understand bearing capacity, settlement and seismic responce of foundation. So measured data are collected about relation between ground and type of foundation, total settlement and differential settlement of already constructed large structures, and it is done to investigate the real condition and to examine allowable settlement. Investigated structures are mainly foreign nuclear power plant and domestic and foreign high buildings. The higher buildings are, the more raft foundation are for type of foundation and the higher contact pressure are to similar to a nuclear power plant. So discussion is done about mainly raft foundation. It is found that some measured maximum total settlements are larger than already proposed allowable values. So empirical allowable settlement is derived from measured values considering the effect of the width of base slab, contact pressure and foundation ground. Differential settlement is investigated about relation to maximum total settlement, and is formulated considering the width and the rigidity of base slab. Beside the limit of differential settlement is obtained as foundation is damaged, and the limit of maximum total settlement is obtained by combining this and above mentioned relation. Obtained allowable value is largely influenced by the width of base slab, and becomes less severe than some already proposed values. So it is expected that deformation of foundation is rationaly investigated when large structure as nuclear power plant is constructed on soft ground. (author)

Dynamic Analysis of Thick Plates Including Deep Beams on Elastic Foundations Using Modified Vlasov Model

Directory of Open Access Journals (Sweden)

Korhan Ozgan

2013-01-01

Full Text Available Dynamic analysis of foundation plate-beam systems with transverse shear deformation is presented using modified Vlasov foundation model. Finite element formulation of the problem is derived by using an 8-node (PBQ8 finite element based on Mindlin plate theory for the plate and a 2-node Hughes element based on Timoshenko beam theory for the beam. Selective reduced integration technique is used to avoid shear locking problem for the evaluation of the stiffness matrices for both the elements. The effect of beam thickness, the aspect ratio of the plate and subsoil depth on the response of plate-beam-soil system is analyzed. Numerical examples show that the displacement, bending moments and shear forces are changed significantly by adding the beams.

REVIEW OF MODERN TECHNOLOGIES OF REINFORCEMENT AND STABILIZATION OF SOFT SOILS

Directory of Open Access Journals (Sweden)

Romanov Nikita Valer’evich

2018-05-01

Full Text Available Subject: description of the current situation in technologies of soil improvement, namely mechanical and hydraulic consolidation of soils and vertical reinforcement of soils for different types of soft soils. Research objectives: demonstration of modern possibilities and approaches to the design and construction of improved soils. Materials and methods: in this paper, we consider such technologies of ground improvement as dynamic compaction, hydraulic consolidation (vertical drain consolidation, Menard vacuum consolidation, vertical reinforcement of soils (CMC - controlled modulus columns. Results: the result of the study is an intuitive representation of the applicability of described technologies for various types of soft soils. Conclusions: the technologies of ground improvement considered in this article are an effective alternative to both pile foundations and soil replacement. To this day, industrial implementation of soil improvement technologies has proved its applicability, efficiency and competitiveness.

An Operational In Situ Soil Moisture & Soil Temperature Monitoring Network for West Wales, UK: The WSMN Network.

Science.gov (United States)

Petropoulos, George P; McCalmont, Jon P

2017-06-23

This paper describes a soil moisture dataset that has been collecting ground measurements of soil moisture, soil temperature and related parameters for west Wales, United Kingdom. Already acquired in situ data have been archived to the autonomous Wales Soil Moisture Network (WSMN) since its foundation in July 2011. The sites from which measurements are being collected represent a range of conditions typical of the Welsh environment, with climate ranging from oceanic to temperate and a range of the most typical land use/cover types found in Wales. At present, WSMN consists of a total of nine monitoring sites across the area with a concentration of sites in three sub-areas around the region of Aberystwyth located in Mid-Wales. The dataset of composed of 0-5 (or 0-10) cm soil moisture, soil temperature, precipitation, and other ancillary data. WSMN data are provided openly to the public via the International Soil Moisture Network (ISMN) platform. At present, WSMN is also rapidly expanding thanks to funding obtained recently which allows more monitoring sites to be added to the network to the wider community interested in using its data.

Case study of soil-structure interaction for nuclear power plants

International Nuclear Information System (INIS)

Lee, A.J.H.

1975-01-01

The dynamic response of a turbine pedestal foundation was analyzed for earthquake and emergency unbalanced loadings in view of satisfactory machine performance and safety consideration. A method of studying the soil-structure interaction effect on such response aiming directly toward a realistic design of the pedestal and also the foundation mat is described. The method utilized the concept underlying the fundation spring approach. Unlike the conventional ones, this concrete pedestal complex has its stiffness and stability provided by shear walls, rib plates, girders and horizontal diaphrams. This necessitated the use of a three-dimensional finite element model as an original mathematical static model consisting of line, surface and solid elements. The mat was also modeled as a flexible mat. For soil-structure interaction effect the foundation compliance functions were represented by frequency independent soil springs distributed at the nodes of the mat, oriented in the global axes. For accurate springs, in magnitude and distribution, for the irregular shape of the mat considered, another finite element model was constructed to simulate a rigid disc (with the true shape) resting on the elastic half-space. The static model was then reduced to a dynamic model containing only those degrees of freedom sufficient to reflect significant response of the complex and its components. For the flexible slab and spring distribution used, the present soil-structure model allowed a better prediction of responses not only at floor elevations where major structural components intersect but also at the interior points of floors and walls where amplification in high frequency response is important. With the method outlined, realistic dynamic responses of the girders which support the machine bearing were studied in detail

Seismic response analysis of a nuclear reactor structure considering nonlinear soil-structure interaction

International Nuclear Information System (INIS)

Bhaumik, Lopamudra; Raychowdhury, Prishati

2013-01-01

Highlights: • Seismic response analysis of an internal shearwall of a reactor is done. • Incremental dynamic analysis is performed with 30 recorded ground motions. • Equivalent viscous damping increases up to twice when nonlinear SSI is considered. • Roof drift demand increases up to 25% upon consideration of foundation nonlinearity. • Base shear, base moment and ductility reduce up to 62%, 40%, and 35%, respectively. - Abstract: This study focuses on the seismic response analysis of an internal shearwall of a typical Indian reactor resting on a medium dense sandy silty soil, incorporating the nonlinear behavior of the soil-foundation interface. The modeling is done in an open-source finite element framework, OpenSees, where the soil-structure interaction (SSI) is modeled using a Beam-on-Nonlinear-Winkler-Foundation (BNWF) approach. Static pushover analysis and cyclic analysis are performed followed by an incremental dynamic analysis (IDA) with 30 recorded ground motions. For performing IDA, the spectral acceleration of each motion corresponding to the fundamental period, S a (T 1 )is incremented from 0.1 g to 1.0 g with an increment step of 0.1 g. It is observed from the cyclic analysis that the equivalent viscous damping of the system increases upto twice upon incorporation of inelastic SSI. The IDA results demonstrate that the average peak base shear, base moment and displacement ductility demand reduces as much as 62%, 40%, and 35%, respectively, whereas the roof drift demand increases up to 25% upon consideration of foundation nonlinearity for the highest intensity motion. These observations indicate the need of critical consideration of nonlinear soil-structure interaction as any deficient modeling of the same may lead to an inaccurate estimation of the seismic demands of the structure

Seismic response analysis of a nuclear reactor structure considering nonlinear soil-structure interaction

Energy Technology Data Exchange (ETDEWEB)

Bhaumik, Lopamudra, E-mail: lbhaumi2@illinois.edu [University of Illinois at Urbana-Champaign (United States); Raychowdhury, Prishati, E-mail: prishati@iitk.ac.in [Indian Institute of Technology Kanpur (India)

2013-12-15

Highlights: • Seismic response analysis of an internal shearwall of a reactor is done. • Incremental dynamic analysis is performed with 30 recorded ground motions. • Equivalent viscous damping increases up to twice when nonlinear SSI is considered. • Roof drift demand increases up to 25% upon consideration of foundation nonlinearity. • Base shear, base moment and ductility reduce up to 62%, 40%, and 35%, respectively. - Abstract: This study focuses on the seismic response analysis of an internal shearwall of a typical Indian reactor resting on a medium dense sandy silty soil, incorporating the nonlinear behavior of the soil-foundation interface. The modeling is done in an open-source finite element framework, OpenSees, where the soil-structure interaction (SSI) is modeled using a Beam-on-Nonlinear-Winkler-Foundation (BNWF) approach. Static pushover analysis and cyclic analysis are performed followed by an incremental dynamic analysis (IDA) with 30 recorded ground motions. For performing IDA, the spectral acceleration of each motion corresponding to the fundamental period, S{sub a}(T{sub 1})is incremented from 0.1 g to 1.0 g with an increment step of 0.1 g. It is observed from the cyclic analysis that the equivalent viscous damping of the system increases upto twice upon incorporation of inelastic SSI. The IDA results demonstrate that the average peak base shear, base moment and displacement ductility demand reduces as much as 62%, 40%, and 35%, respectively, whereas the roof drift demand increases up to 25% upon consideration of foundation nonlinearity for the highest intensity motion. These observations indicate the need of critical consideration of nonlinear soil-structure interaction as any deficient modeling of the same may lead to an inaccurate estimation of the seismic demands of the structure.

Earthquake analysis with nonlinear soil-structure interaction and nonlinear supports of components

International Nuclear Information System (INIS)

Hansson, V.

1990-01-01

For the determination of the seismic response of a structure the soil-structure interaction in most cases is modelled by a mass-spring-damper-system. Normally design concepts for components and piping are based on linear calculations and stress limitations. A concept for a reactor building for the HTR 100 consisted of a relatively high structure compared with the dimensions of the foundation. The structure was comparatively deep embedded in the soil, so here the embedment influences significantly the soil-structure interaction. The assembly of reactor vessel, heat exchanger and circulators has a height of about 37 m. Supports are arranged at different levels. Due to temperature deformations of the vessel and of the support constructions small gaps at the supports may only be avoided by complicated constructions of the supports. Nonlinear analyses were performed for soil, building and component with all supports. The finite element analyses used time histories. In order to describe the radiation damping the hysteresis of the soil with 1 percent material damping was considered. Nonlinearities in the interface of soil and foundation and due to gaps and friction at the supports were taken into account. The stiffness of the support constructions influences reactions and accelerations to a high extent. Properly chosen stiffnesses of the support constructions lead to a behaviour similar to linear elastic behaviour. 13 figs

Sudden Arrhythmia Death Syndromes (SADS) Foundation

Science.gov (United States)

... SADS Foundation UK SADS Foundation Netherlands SADS Foundation China SADS Foundation Hong Kong Search for: Log in ... research crucial for health of patients and the economy 7/18/2017 More funding for heart disease ...

STRAIN-STRESS DISTRIBUTION OF “HOMOGENEOUS” SOIL MASS DURING THE LOAD TRANSMITTED THROUGH THE LIMITED AREA IN THE PLAN, APPLIED INSIDE THE ELASTIC HOMOGENEOUS SOIL MASS

Directory of Open Access Journals (Sweden)

BOLSHAKOV V. I.

2017-03-01

Full Text Available Summary. Based on the current understanding of the piles work in clayey soils; that is forming during driving process a compacted core (compacted platform in the pile tip plane and transferring the load from the pile (from the piling foundation not through the pile tip but through the pressed core (compacted platform, the stress in the soil mass by the load applied inside the elastic half-space is determined with the change in the calculated scheme of load transferring to the “homogeneous” soil mass.

Influence of Characteristic-Soil-Property-Estimation Approach on the Response of Monopiles for Offshore Wind Turbines

DEFF Research Database (Denmark)

Andersen, Lars Vabbersgaard; Sørensen, John Dalsgaard; Kim, Sun-Bin

2015-01-01

Different approaches to estimation of the characteristic undrained shear strength of soil are discussed, based on 12 cone penetration tests (CPTs) carried out within a soil volume representative of an offshore monopile foundation. The paper is focused on the statistical treatment of the data, and...

Changes in canopy structure and ant assemblages affect soil ecosystem variables as a foundation species declines

DEFF Research Database (Denmark)

Kendrick, Joseph A.; Ribbons, Relena Rose; Classen, Aimee Taylor

2015-01-01

in ant species composition would interact to alter soil ecosystem variables. In the Harvard Forest Hemlock Removal Experiment (HF-HeRE), established in 2003, T. canadensis in large plots were killed in place or logged and removed to mimic adelgid infestation or salvage harvesting, respectively. In 2006...... (richness and abundance) of ants increases rapidly as T. canadensis is lost from the stands. Because ants live and forage at the litter-soil interface, we hypothesized that environmental changes caused by hemlock loss (e.g., increased light and warmth at the forest floor, increased soil pH) and shifts......, we built ant exclosure subplots within all of the canopy manipulation plots to examine direct and interactive effects of canopy change and ant assemblage composition on soil and litter variables. Throughout HF-HeRE, T. canadensis was colonized by the adelgid in 2009, and the infested trees are now...

Seismic response analysis of nuclear reactor buildings under consideration of soil-structure interaction with torsional behavior

International Nuclear Information System (INIS)

Mizuno, N.; Iida, T.; Tsushima, Y.; Araki, T.; Nojima, O.

1977-01-01

In this paper, the seismic response analysis is described in detail for estimating the soil-structure interaction effects with the torsional behavior. The analytical method is firstly shown for estimating the stiffness of reactor building by the bending-shear and torsion theory of the thin wall sections in regard to the behavior of structure. The three-dimensional behavior of structure can be obtained more briefly and simply by the proposed method. Secondly, the dynamical soil-foundation coefficient for estimating the dissipation of vibrational energy on the ground is derived by H. Tajimi's theory which is based on a solution of the propagation of seismic waves caused by point excitation on the surface of the elastic half-space medium. The above results give the vibrational impedances of the soil-foundation corresponding to the static soil coefficient, which is defined to the excitation force in the frequency domain. In order to analyze to the equivalues of reactor building, the authors thirdly attempt to approximate the dynamic soil-foundation coefficient as the frequency transfer function of displacement. The complex damping is used for more suitably estimating the elastic structural damping effects of structure. The regression analysis of many degrees of freedom is fourthly attempted for estimating the natural periods annd equivalent viscous damping ratios directly from the experimental results by the forced vibrational test performed in 1974. The analytical results are finally shown for simulating and comparing with the above-mentioned experimental results

The role of foundations: Rockefeller Foundation.

Science.gov (United States)

Rockefeller, David

The consequences of climate change and the impacts of human activity on the environment have made it clearer than ever before that we must evolve our current model of public health to better account for the inextricable link between human health and the natural systems on which it depends-creating a "public health 2.0" that builds on the innovations of the twentieth century to account for a world where humans have bypassed planetary boundaries to achieve well-being. First coined at the Rockefeller Foundation's Centennial gathering in Beijing in 2013, "Planetary Health" will factor in future health and environmental harms over present-day gains, particularly those that disproportionately affect the poor and those in developing nations. To build this new field, foundations must address the challenge of information, increasing support for research to bridge knowledge gaps on the links between economic development, natural systems, and human health.

Dynamic behaviour of raft and pile foundations tests and computational models. Pt. 1

International Nuclear Information System (INIS)

Betbeder, J.; Garnier, J.C.; Gauvain, J.; Jeandidier, C.

1981-01-01

Pile foundations are commonly used for many types of buildings where the bearing capacity of soil is poor. For nuclear power plants buildings, however, there seems to be a fairly general reluctancy to accept design on piles, as it is considered difficult to demonstrate the safety of these foundations with respect to earthquakes, due to the relative lack of validation of the currently available aseismic design methods. Being conscious that pile foundations might be worth considering for future nuclear sites in France and that the reliability of design methods should be backed by experimental data, ELECTRICITE DE FRANCE decided in 1978 to undertake a series of tests, aimed at assessing the validity of computational models for seismic behaviour of pile foundations and trying to define better models if necessary. These tests on reduced scale structure, including various types of raft and pile foundations and different kinds of dynamic excitation (harmonic, earthquake simulation, impulsive release of a static force) have been made at the NICE airport site. The present paper deals with the general description of the tests and the first part of interpretation work, limited to in-structure harmonic excitation and earthquake simulation tests analyzed by simple spring -dashpot analytical models. The two following papers (K5-6 and K5-7) are devoted to specialized topics in relation with the interpretation of tests, i-e ground motions analysis for earthquake simulation and research work on a new computational model. Although preliminary conclusions can be drawn from the results obtained so far, further work will be necessary to reach a conclusive assessment on this difficult subject. (orig.)

Compressor Foundation Analysis Tool(COFANTO)

NARCIS (Netherlands)

Eijk, A.; Lentzen, S.S.K; Zuada Coelho, B.E.; Galanti, F.M.B.

2012-01-01

Reciprocating compressors are generally supported on a heavy concrete foundation. In spite of the large inertia and stiffness of the foundation, problems can occur due to interaction between the mechanical installation and the foundation. Two types of problems may occur. In the first type, the

Ekspansif soil solution in the villages at Trenggalek

Science.gov (United States)

Triastuti, Nusa Setiani

2017-11-01

District 2/3 hills with easy sliding and land survey results showed the soil because it consists of expansive soil Survey some villages who experience insatiability or failure, a secondary analysis of the data gathered from the expert on geology, Trenggalek geological map, Trenggalek geography. Ground location researched several villages, the Terbis village of focus discussion of the landslides and plan of relocation. In the watching a black. Colored soil and easily slide, showed very expansive soil due to montmorrelite. While soil relocation contour relative is more stable because the land of kaolin and invisible water sources that could push the land. Expansive soil in the village of solution should be cheap, easily obtainable, not damaging the fertility of the soil, groundwater should be awake to the source of life, ease of implementation, utilizing local materials and use modest tools and equipment. Under the soil surface do not get there water stored in the soil until deep the water because it will slide the ground. The analysis must meet the 7 items above and steady the contour. Design of building installed sub drain, the shallow bore foundations tied tie beam, floor plate into the unity of the structure.

Multi-phase physicochemical modeling of soil-cementitious material interaction

International Nuclear Information System (INIS)

Nakarai, Kenichiro; Ishida, Tetsuya; Maekawa, Koichi

2005-01-01

Multi-phase physicochemical modeling based on thermodynamic approach is studied on gel and capillary pores of nano-micrometers and large voids of micro-millimeters among soil foundation. A computational method about transportation of moisture and ions in pore structure for simulating concrete performance was extended for predicting time-dependent material properties of cemented soil. The proposed model was verified with experimental results of cement hydration, change of relative humidity and leaching of calcium ion from cement hydrate to underground water. (author)

Stress-strain response of plastic waste mixed soil.

Science.gov (United States)

Babu, G L Sivakumar; Chouksey, Sandeep Kumar

2011-03-01

Recycling plastic waste from water bottles has become one of the major challenges worldwide. The present study provides an approach for the use plastic waste as reinforcement material in soil. The experimental results in the form of stress-strain-pore water pressure response are presented. Based on experimental test results, it is observed that the strength of soil is improved and compressibility reduced significantly with addition of a small percentage of plastic waste to the soil. The use of the improvement in strength and compressibility response due to inclusion of plastic waste can be advantageously used in bearing capacity improvement and settlement reduction in the design of shallow foundations. Copyright © 2010 Elsevier Ltd. All rights reserved.

An effective spring-mass model for soil-structure interaction analysis

International Nuclear Information System (INIS)

Hirasawa, M.; Tanaka, O.; Takasaki, Y.; Miyama, T.

1985-01-01

This paper discusses an analytical method to account for dynamic stiffness of foundation embedded in multilayered soil medium and its application. The method is based on the solution of three-dimensional wave equation subjected to dynamic loading within layered medium. The dynamic stiffness is applied to spring-mass model for a nuclear reactor building embedded in layered soil. Numerical examples show that the stiffness of bottom of base-mat in soil is different from one on surface while the difference has not so considerable effects on the seismic response of the building and the floor response spectra. (orig.)

RELIABILITY BASED DESIGN OF FIXED FOUNDATION WIND TURBINES

Energy Technology Data Exchange (ETDEWEB)

Nichols, R.

2013-10-14

Recent analysis of offshore wind turbine foundations using both applicable API and IEC standards show that the total load demand from wind and waves is greatest in wave driven storms. Further, analysis of overturning moment loads (OTM) reveal that impact forces exerted by breaking waves are the largest contributor to OTM in big storms at wind speeds above the operating range of 25 m/s. Currently, no codes or standards for offshore wind power generators have been adopted by the Bureau of Ocean Energy Management Regulation and Enforcement (BOEMRE) for use on the Outer Continental Shelf (OCS). Current design methods based on allowable stress design (ASD) incorporate the uncertainty in the variation of loads transferred to the foundation and geotechnical capacity of the soil and rock to support the loads is incorporated into a factor of safety. Sources of uncertainty include spatial and temporal variation of engineering properties, reliability of property measurements applicability and sufficiency of sampling and testing methods, modeling errors, and variability of estimated load predictions. In ASD these sources of variability are generally given qualitative rather than quantitative consideration. The IEC 61400‐3 design standard for offshore wind turbines is based on ASD methods. Load and resistance factor design (LRFD) methods are being increasingly used in the design of structures. Uncertainties such as those listed above can be included quantitatively into the LRFD process. In LRFD load factors and resistance factors are statistically based. This type of analysis recognizes that there is always some probability of failure and enables the probability of failure to be quantified. This paper presents an integrated approach consisting of field observations and numerical simulation to establish the distribution of loads from breaking waves to support the LRFD of fixed offshore foundations.

Hybrid modelling of soil-structure interaction for embedded structures

International Nuclear Information System (INIS)

Gupta, S.; Penzien, J.

1981-01-01

The basic methods currently being used for the analysis of soil-structure interaction fail to properly model three-dimensional embedded structures with flexible foundations. A hybrid model for the analysis of soil-structure interaction is developed in this investigation which takes advantage of the desirable features of both the finite element and substructure methods and which minimizes their undesirable features. The hybrid model is obtained by partitioning the total soil-structure system into a nearfield and a far-field with a smooth hemispherical interface. The near-field consists of the structure and a finite region of soil immediately surrounding its base. The entire near-field may be modelled in three-dimensional form using the finite element method; thus, taking advantage of its ability to model irregular geometries, and the non-linear soil behavior in the immediate vicinity of the structure. (orig./WL)

The logical foundations of mathematics

CERN Document Server

Hatcher, William S

1981-01-01

The Logical Foundations of Mathematics offers a study of the foundations of mathematics, stressing comparisons between and critical analyses of the major non-constructive foundational systems. The position of constructivism within the spectrum of foundational philosophies is discussed, along with the exact relationship between topos theory and set theory.Comprised of eight chapters, this book begins with an introduction to first-order logic. In particular, two complete systems of axioms and rules for the first-order predicate calculus are given, one for efficiency in proving metatheorems, and

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

DEFF Research Database (Denmark)

Sørensen, Søren Peder Hyldal

Offshore wind power is a domestic, sustainable and largely untapped energy resource. Today, the modern offshore wind turbine offers competitive production prices compared to other sources of renewable energy. Therefore, it is a key technology in breaking the dependence on fossil fuels...... and in achieving the energy and climate goals of the future. For offshore wind turbines, the costs of foundation typically constitute 20-30% of the total costs. Hence, improved methods for the design of foundations for offshore wind turbines can increase the competitiveness of offshore wind energy significantly....... The monopile foundation concept has been employed as the foundation for the majority of the currently installed offshore wind turbines. Therefore, this PhD thesis concerns the soil-pile interaction for non-slender, large-diameter offshore piles. A combination of numerical and physical modelling has been...

Soil quality, theory and applications. a critical analysis

Directory of Open Access Journals (Sweden)

Elio Coppola

2009-04-01

Full Text Available In its common meaning, the concept of “soil quality” is based on evaluating criteria that are subjective and “anthropocentric” rather than objective and “pedocentric”. Several “desirable” or “undesirable” soil conditions and characteristics are considered from the human point of view, disregarding the pedogenetic features. Such an approach perilously leads to support the idea of a “pedogenetic discrimination”, which a priori privileges “superior” vs. “inferior” soils, thus discrediting a large part of soil Subgroups, Great Groups, Suborders, and even whole taxonomic Orders. So, a number of soil functions, such as genic reserve guarantee of space-temporal bio-diversity, environmental good cradle of civilization, foundation of the landscape, as well as upholder of man heritage, are neglected at all. If “quality” only concerned rich and fertile soils, there would be the great and looming risk to definitively take “poor” soils away from agriculture, landscape and global pedological reserve. It is necessary to reconsider the concept of “soil quality” as “soil functionality”, that is to say “aptitude of soil to express its own potential”, bringing out the essential environmental, socio-economic and cultural soil roles on the basis of the inherent conditions and characteristics arising from its peculiar pedogenetic history.

Soil fauna research in Poland: earthworms (Lumbricidae

Directory of Open Access Journals (Sweden)

Pączka Grzegorz

2015-06-01

Full Text Available Living organisms are the foundation of ecosystem services. Of particular notice is zooedaphone, often underestimated and basically unknown to the general public. The present review summarizes the current state of knowledge related to earthworms occurring in natural and anthropogenically altered habitats in Poland, in the context of the requirement for protection of soil biodiversity.

Robert Wood Johnson Foundation

Science.gov (United States)

Robert Wood Johnson Foundation Search How We Work Our Focus Areas About RWJF Search Menu How We Work Grants ... Learn more For Grantees and Grantseekers The Robert Wood Johnson Foundation funds a wide array of programs ...

An elastoplastic homogenization procedure for predicting the settlement of a foundation on a soil reinforced by columns

OpenAIRE

ABDELKRIM, Malek; DE BUHAN, Patrick

2007-01-01

This paper presents an elastoplastic homogenization method applied to a soil reinforced by regularly distributed columns. According to this method, the composite reinforced soil is regarded, from a macroscopic point of view, as a homogeneous anisotropic continuous medium, the elastic as well as plastic properties of which can be obtained from the solution to an auxiliary problem attached to the reinforced soil representative cell. Based upon an approximate solution to this problem, in which p...

An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil

OpenAIRE

Weijing Yao; Jianyong Pang; Yushan Liu

2018-01-01

Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry inject...

Thinking and Countermeasures for Rational Utilization of Soil Fertility in Modern Agriculture Developping

Directory of Open Access Journals (Sweden)

WENG Bo-qi

2014-02-01

Full Text Available Soil is not only an important foundation for agricultural production, but also is the safeguard of human survival. Soil quality is close-ly related with food safety and argo-ecological environment. Soil fertility is the support of modern agricultural development. Multiple disci-plines and specialties are involved in researches of soil cultivating process. Nowadays, the understanding of soil fertility has changed from a-gricultural production to environmental security and resource exploitation, even larger scales to ecological health and global soil change. In this review, the characteristics and inherent link between soil and agriculture were comprehensive expounded from the aspects of long-term fertilization trials, soil cultivation techniques, and modern agriculture development. The challenge and prospect faced in soil science research field were also analyzed. Finally, several suggestions and countermeasures were proposed to the researches of soil science in future.

Dynamic response of aircraft impact of a reactor building with protective shell on independent foundation

International Nuclear Information System (INIS)

Constantopoulos, I.V.; Vardanega, C.; Attalla, I.

1981-01-01

Aircraft impact loading can penalize significantly the design of the equipment in a conventional containment building. An alternative scheme was developed in an attempt to reduce the aircraft impact response. A preliminary study was carried out to investigate the feasibility of the alternative scheme. This study was made in such perspective and for the purpose of comparing the response to aircraft impact of a standard reactor building, to that of a reactor building having an independently founded outer shell. In the second scheme, the outer shell is meant to receive the aircraft impact, so that the load will be transmitted to the reactor building internals only by way of the structure-soil-structure system. In both cases, the aircraft impact was postulated to occur on a linear single degree of freedom oscillator which modeled, approximately, the plastification of the impact area. The soil was considered as a half-space with properties corresponding to a medium stiff soil, and modeled by lumped soil springs and dashpots. The reactor internals, inner shell and protective outer shell were modeled with beam elements and concentrated inertias. In modeling the coupled system, soil-structure interaction and structure-to-structure interaction through the soil were represented by a global stiffness matrix corresponding to the three degrees the freedom of each foundation, i.e. horizontal, vertical and rocking. (orig./HP)

Causes of poor sealant performance in soil gas resistant foundations

International Nuclear Information System (INIS)

Scott, A.

1993-01-01

The surface permeability of concrete walls and floors in houses was measured with a specially designed permeameter, based on measuring the air-flow induced by a pressure difference across a temporary test seal applied to a surface. The permeability of bulk concrete is 10 -16 m 2 . Areas free of surface defects had permeability ranging from 10 -14 to 10- 16 m 2 . However, surface defects are common on concrete wall surfaces, which increase the permeability to >10 -12 m 2 . This is too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Satisfactory seals require either extended contact width or mechanical removal of the surface layer. (orig.). (2 figs., 1 tab.)

Foundations of measurement

CERN Document Server

Suppes, Patrick

1989-01-01

Foundations of Measurement offers the most coherently organized treatment of the topics and issues central to measurement. Much of the research involved has been scattered over several decades and a multitude of journals--available in many instances only to specialties. With the publication of Volumes two and three of this important work, Foundations of Measurement is the most comprehensive presentation in the area of measurement.

Reliability Evaluation of a Concrete Crown Wall on a Rubble Mound Breakwater considering Sliding Failure, Overturning and Rupture Failure of the Foundation

DEFF Research Database (Denmark)

Christiani, E.; Sørensen, Jørgen S.; Burcharth, Hans F.

1994-01-01

and rupture failure in the rubble mound are taken into account. The method of probabilistic foundation stability analysis is presented by the example of a translation slip failure involving kinematically correct slip surfaces and failure zones in friction based soil. A conventional static quasi-static...

Study on the Bearing Mode and Force Transfer Path of Composite Bucket Foundations

Directory of Open Access Journals (Sweden)

Shaohua He

2017-07-01

Full Text Available This paper elaborates on a new composite bucket foundation (CBF structural system for offshore wind turbines. The proposed CBF consists of a special force transition section, a beam system structure upper steel bucket cover and a large-scale steel bucket with honeycomb structure rooms. It can be prefabricated onshore, self-floated on the sea and then towed to the appointed sea area before sinking to the sea soil under negative pressure. This is called the “one-step” installation technology. Arc- and line-type bucket foundations are calculated by both theory and the finite element method to discuss their force transfer paths and bearing modes. Owning to the special structural form, the transition section can effectively convert the huge load and bending moment into controllable tension and compressive stress, as well as adjust the structure balance. The bearing model and percentage of each part of the composite foundation under monotonous and ultimate load conditions are also calculated. Results indicate that the bearing mode of CBF is a typical top cover mode. In addition, the curvature impact of arc-type is studied and the results reveal that the structure type of the transition section is more important than the diameter ratio between the bottom transition section and the bucket.

The role of geophysical ERT method to evaluate the leakproofness of diapragm wall of deep foundation trenches on the example of the construction of retail and office complex in Lublin, Poland

Directory of Open Access Journals (Sweden)

Pacanowski Grzegorz

2014-12-01

Full Text Available This paper addresses the problem of assessing the leakproofness of the bottom of a deep foundation trench, secured by cavity wall, using geophysical methods of electrical resistivity tomography. The study was conducted on a large construction project in Lublin, in a place where there are complicated soil-water conditions: the groundwater level is above the proposed depth of foundation trench, the subsoil is heterogeneous, and there are karsted and weathered carbonate sediments with confined aquifer below the bottom of the trench. A hydraulic fracture occurred at the bottom of the trench during the engineering works, which caused the water flow into the trench. In order to recognize the soil-water conditions the first stage of geophysical measurements of electrical resistivity tomography (ERT was made. The applied methodology allowed to determine the extent of the hydraulic fracture zone within the bottom of foundation trench. In order to assess the leakproofness of Diaphragm Wall the geophysical ERT measurements were repeated (stage 2 A clear reduction in the value of the electrical resistivity of soils in the area of hydraulic fracture was caused by clay injection. The results of ERT measurements are discussed and graphically presented.

Introductory guide to foundations

CSIR Research Space (South Africa)

Donaldson, GW

1973-01-01

Full Text Available . The secret of successful foundations is knowing just how much the subsoil can support. As one goes deeper, the ability of the ground to support a load becomes greater so that the foundation engineer can choose between deep foundations and the expense... beginstoinaease. When the house is ~ ~ p l e t e d it shelters the gmund f f ~ m sun and wind and the moisture content i- wen more rapidly- Leaking pipes and sewers increase the volume of water fed to the clay while ornamental trees planted around the house...

A Constitutive Relationship for Gravelly Soil Considering Fine Particle Suffusion.

Science.gov (United States)

Zhang, Yuning; Chen, Yulong

2017-10-23

Suffusion erosion may occur in sandy gravel dam foundations that use suspended cutoff walls. This erosion causes a loss of fine particles, degrades the soil strength and deformation moduli, and adversely impacts the cutoff walls of the dam foundation, as well as the overlying dam body. A comprehensive evaluation of these effects requires models that quantitatively describe the effects of fine particle losses on the stress-strain relationships of sandy gravels. In this work, we propose an experimental scheme for studying these types of models, and then perform triaxial and confined compression tests to determine the effects of particle losses on the stress-strain relationships. Considering the Duncan-Chang E-B model, quantitative expressions describing the relationship between the parameters of the model and the particle losses were derived. The results show that particle losses did not alter the qualitative stress-strain characteristics of the soils; however, the soil strength and deformation moduli were degraded. By establishing the relationship between the parameters of the model and the losses, the same model can then be used to describe the relationship between sandy gravels and erosion levels that vary in both time and space.

A Constitutive Relationship for Gravelly Soil Considering Fine Particle Suffusion

Directory of Open Access Journals (Sweden)

Yuning Zhang

2017-10-01

Full Text Available Suffusion erosion may occur in sandy gravel dam foundations that use suspended cutoff walls. This erosion causes a loss of fine particles, degrades the soil strength and deformation moduli, and adversely impacts the cutoff walls of the dam foundation, as well as the overlying dam body. A comprehensive evaluation of these effects requires models that quantitatively describe the effects of fine particle losses on the stress-strain relationships of sandy gravels. In this work, we propose an experimental scheme for studying these types of models, and then perform triaxial and confined compression tests to determine the effects of particle losses on the stress-strain relationships. Considering the Duncan-Chang E-B model, quantitative expressions describing the relationship between the parameters of the model and the particle losses were derived. The results show that particle losses did not alter the qualitative stress-strain characteristics of the soils; however, the soil strength and deformation moduli were degraded. By establishing the relationship between the parameters of the model and the losses, the same model can then be used to describe the relationship between sandy gravels and erosion levels that vary in both time and space.

Initial data of seismic input and soil conditions of Kozloduy NPP site. Extension to Part 2 soil conditions, issued October '93

International Nuclear Information System (INIS)

Boyadjiev, Z.

1995-01-01

On the basis of the results of the carried out experimental (laboratory and in situ) investigations of the dynamic characteristics, the following conclusions for the Kozloduy NPP site are presented. (1) The established through experimental studies relationships for the shear module and the damping factor as strain dependent of representative samples of soils of the site profile, can be used for all similar soils in the profile in the different parts of the site, taking into account the possible differences by means of the initial shear module in the normalized relationship for the respective generalized soil type. (2) When solving the problems of the site response and the 'soil - structure analysis', the geotechnical seismic model of the 'free field' profile can be assumed for all parts of the NPP site. (3) The changes of the lithological profile in different parts of the site, in respect to type and thickness, as well as in view of the different way and depth of the NPP structures foundation, make it necessary the elaboration of a geotechnical seismic model of the profile below the foundation plates of the reactor buildings of the NPP units in each particular case. These models can be made out on the basis of the summarized data about the shear velocities of the soil types, the lithological data of the studied boreholes in these places and the data having natural bulk density from 30 - 40 m depth determined by the laboratory studies of samples of these soils, assuming with approximation that the geotechnical seismic model below this depth is the same as the one of the 'free field'. (4) Studies have been carried out through in situ and laboratory studies of all the fundamental structures on the NPP site and the results of them are sufficient as an addition to the present initial data for solving the problems of the site response and the 'soil-structure inter-action' analyses of each structure

Comprehensive Evaluation of Soil Near Uranium Tailings, Beishan City, China.

Science.gov (United States)

Xun, Yan; Zhang, Xinjia; Chaoliang, Chen; Luo, Xuegang; Zhang, Yu

2018-06-01

To evaluate the impact of uranium tailings on soil composition and soil microbial, six soil samples at different distance from the uranium tailings (Beishan City, China) were collected for further analysis. Concentrations of radionuclides ( 238 U and 232 Th), heavy metals (Mn, Cd, Cr, Ni, Zn, and Pb) and organochlorine pesticide were determined by ICP-MS and GC, they were significantly higher than those of the control. And the Average Well Color Development as well as the Shannon, the Evenness, and the Simpson index were calculated to evaluate the soil microbial diversity. The carbon utilization model of soil microbial community was also analyzed by Biolog-eco. All results indicated that uranium tailings leaded to excessive radionuclides and heavy metals, and decreased the diversity of the soil microbial community. Our study will provide a valuable basis for soil quality evaluation around uranium tailing repositories and lay a foundation for the management and recovery of uranium tailings.

Kellogg Foundation Initiative: Rewriting the Way Foundations Do Business in Indian Country.

Science.gov (United States)

Boyer, Paul

2000-01-01

Describes the multi-million dollar initiative announced by W. K. Kellogg Foundation in 1995 to support the Native American Higher Education Initiative, and how the Kellogg initiative deserves attention from the nation as a whole because it is attempting to fundamentally rewrite the way foundations do business with Indian communities. (VWC)

Dramix® Steel fibres in residential foundation slabs in Czech Republic: design approach

Science.gov (United States)

Pouillon, S.

2017-09-01

Steel fibres are used more and more in structural concrete elements, like residential foundation slabs. The development of high performant steel fibres (e.g. Dramix® 4D and 5D), the evolution in standardization and the demand coming from construction companies and investors are pushing this trend. Engineers are using the yield line method to design steel fibre concrete structures in an easy and economical way, especially if the structure has a regular load layout mainly containing wall loads and point loads. The load configuration, soil characteristics and material characteristics determine the final solution.

Swiss Foundation Code 2015 principles and recommendations for the establishment and management of grant-making foundations

CERN Document Server

Sprecher, Thomas; Schnurbein, Georg von

2015-01-01

The publication 'Swiss Foundation Code' contains practical governance guidelines on the topics of the establishment of foundations, their organisation, management and supervision, their charitable work and also on finance and investment policy for the contemporary and professional management of charitable foundations.

Modelling Foundations and Applications

DEFF Research Database (Denmark)

This book constitutes the refereed proceedings of the 8th European Conference on Modelling Foundations and Applications, held in Kgs. Lyngby, Denmark, in July 2012. The 20 revised full foundations track papers and 10 revised full applications track papers presented were carefully reviewed...

The Jan Korec Foundation

International Nuclear Information System (INIS)

2007-01-01

In this video-film activities of the the Jan Korec Foundation are presented. The Jan Korec Foundation supports students of technical sciences, sport activities, science and support of book publishing, humanitarian supports, the environment protection as well as support of different social projects.

Swiss Foundation Code 2009 principles and recommendations for the establishment and management of grant-making foundations

CERN Document Server

Sprecher, Thomas; Janssen, Martin

2011-01-01

The «Swiss Foundation Code 2009» takes up and completes the first European Good Governance Code for grant-making foundations, published in 2005. It contains practical governance guidelines regarding the establishment, organization, management and monitoring of grant-making foundations as well as making due reference to support activities, financial and investment policies. The abridged English version of the „Swiss Foundation Code 2009“ contains 3 principles and 26 recommendations – but not the extensive commentary parts.

Bucket Foundation Response Under Various Displacement Rates

DEFF Research Database (Denmark)

Vaitkunaite, Evelina; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

2016-01-01

in a multi-bucket foundation system. The foundation model is at a scale of approximately 1:20 prototype foundation size. The tests are performed in a pressure tank with the foundation model installed in dense sand. Based on the data, the conclusion is that the bucket foundation design in a storm case should......The present testing program aims at showing the pore pressure response around a bucket foundation skirt as well as the load and displacement change due to ten different displacement rates. Research findings are useful for a numerical model calibration focusing on the design of the upwind foundation...

Foundations for Critical Thinking

Science.gov (United States)

Bers, Trudy; Chun, Marc; Daly, William T.; Harrington, Christine; Tobolowsky, Barbara F.

2015-01-01

"Foundations for Critical Thinking" explores the landscape of critical-thinking skill development and pedagogy through foundational chapters and institutional case studies involving a range of students in diverse settings. By establishing a link between active learning and improved critical thinking, this resource encourages all higher…

The Monopod Bucket Foundation

DEFF Research Database (Denmark)

Bakmar, Christian LeBlanc; Ahle, Kim; Nielsen, Søren A.

2009-01-01

Following the successful installation of a prototype of a monopod bucket foundation, also called a “monopod suction caisson”, at Horns Rev 2 Offshore Wind Farm, Denmark, in 2009, DONG Energy is currently developing a commercialization strategy. The monopod bucket foundation is a promising...

Bioinformatic approaches reveal metagenomic characterization of soil microbial community.

Directory of Open Access Journals (Sweden)

Zhuofei Xu

Full Text Available As is well known, soil is a complex ecosystem harboring the most prokaryotic biodiversity on the Earth. In recent years, the advent of high-throughput sequencing techniques has greatly facilitated the progress of soil ecological studies. However, how to effectively understand the underlying biological features of large-scale sequencing data is a new challenge. In the present study, we used 33 publicly available metagenomes from diverse soil sites (i.e. grassland, forest soil, desert, Arctic soil, and mangrove sediment and integrated some state-of-the-art computational tools to explore the phylogenetic and functional characterizations of the microbial communities in soil. Microbial composition and metabolic potential in soils were comprehensively illustrated at the metagenomic level. A spectrum of metagenomic biomarkers containing 46 taxa and 33 metabolic modules were detected to be significantly differential that could be used as indicators to distinguish at least one of five soil communities. The co-occurrence associations between complex microbial compositions and functions were inferred by network-based approaches. Our results together with the established bioinformatic pipelines should provide a foundation for future research into the relation between soil biodiversity and ecosystem function.

Mapping specific soil functions based on digital soil property maps

Science.gov (United States)

Pásztor, László; Fodor, Nándor; Farkas-Iványi, Kinga; Szabó, József; Bakacsi, Zsófia; Koós, Sándor

2016-04-01

climatic conditions in the Carpathian Basin. In addition to soil fertility, degradation risk due to N-leaching was also assessed by the model runs by taking into account the movement of nitrate in the profile during the simulated periods. Our paper will present the resulted national maps and some conclusions drawn from the experiences. Acknowledgement: Our work was supported by Iceland, Liechtenstein and Norway through the EEA Grants and the REC (Project No: EEA C12-12) and the Hungarian National Scientific Research Foundation (OTKA, Grant No. K105167).

Soil-Framed Structure Interaction Analysis - A New Interface Element

Directory of Open Access Journals (Sweden)

M. Dalili Shoaei

Full Text Available AbstractInterfacial behavior between soil and shallow foundation has been found so influential to combined soil-footing performance and redistribution of forces in the superstructure. This study introduces a new thin-layer interface element formulated within the context of finite element method to idealize interfacial behavior of soil-framed structure interaction with new combination of degrees of freedom at top and bottom sides of the interface element, compatible with both isoparametric beam and quadrilateral element. This research also tends to conduct a parametric study on respective parameters of the new joint element. Presence of interface element showed considerable changes in the performance of the framed structure under quasi-static loading.

Earthquake response analyses of soil-structure system considering kinematic interaction

International Nuclear Information System (INIS)

Murakami, H.; Yokono, K.; Miura, S.; Ishii, K.

1985-01-01

Improvement of soil-structure interaction analysis has been one of major concerns in earthquake engineering field, especially in nuclear industries, to evaluate the safety of structure accurately under earthquake events. This research aims to develop a rational analytical tool which considers effect of the 'kinematic interaction' satisfactory with a proposed simple low-pass filter. In this paper, first the effect of the kinematic interaction is investigated based on earthquake response analysis of a reactor building using the practical design models: the spring-mass-dashpot system and the 'lattice model', in which a building and soil medium are modeled by a system of lumped masses. Next, the filter is developed based on parametrical studies with various sizes of depth and width of foundations embedded in two-layers soil, which represents more general soil condition in practical designs compared with a homogeneous soil medium. (orig.)

Long-Term Ownership by Industrial Foundations

DEFF Research Database (Denmark)

Børsting, Christa Winther; Kuhn, Johan Moritz; Poulsen, Thomas

2016-01-01

in Denmark. Industrial foundations are independent legal entities without owners or members typically with the dual objective of preserving the company and using excess profits for charity. We use a unique Danish data set to examine the governance of foundation-owned companies. We show that they are long......-term in several respects. Foundations hold on to their shares for longer. Foundation-owned companies replace managers less frequently. They have more conservative capital structures with less leverage. Their companies survive longer. Their business decisions appear to be more long term. This paper supports...... the hypothesis that time horizons are influenced by ownership structures and particularly that industrial foundations promote longtermism. Policymakers which are interested in promoting longtermism should allow and perhaps even encourage the creation of industrial foundations. More generally they should consider...

Assessing the small-strain soil stiffness for offshore wind turbines based on in situ seismic measurements

International Nuclear Information System (INIS)

Versteijlen, W G; Van Dalen, K N; Metrikine, A V; Hamre, L

2014-01-01

The fundamental natural frequency as measured on installed offshore wind turbines is significantly higher than its designed value, and it is expected that the explanation for this can be found in the currently adopted modeling of soil-structure interaction. The small-strain soil stiffness is an important design parameter, as it has a defining influence on the first natural frequency of these structures. In this contribution, in situ seismic measurements are used to derive the small-strain shear modulus of soil as input for 3D soil-structure interaction models to assess the initial soil stiffness at small strains for offshore wind turbine foundations. A linear elastic finite element model of a half-space of solids attached to a pile is used to derive an equivalent first mode shape of the foundation. The second model extends the first one by introducing contact elements between pile and soil, to take possible slip and gap-forming into account. The deflections derived with the 3D models are smaller than those derived with the p- y curve design code. This higher stiffness is in line with the higher measured natural frequencies. Finally a method is suggested to translate the response of 3D models into 1D engineering models of a beam laterally supported by uncoupled distributed springs

SHAKING TABLE TEST AND EFFECTIVE STRESS ANALYSIS ON SEISMIC PERFORMANCE WITH SEISMIC ISOLATION RUBBER TO THE INTERMEDIATE PART OF PILE FOUNDATION IN LIQUEFACTION

Science.gov (United States)

Uno, Kunihiko; Otsuka, Hisanori; Mitou, Masaaki

The pile foundation is heavily damaged at the boundary division of the ground types, liquefied ground and non-liquefied ground, during an earthquake and there is a possibility of the collapse of the piles. In this study, we conduct a shaking table test and effective stress analysis of the influence of soil liquefaction and the seismic inertial force exerted on the pile foundation. When the intermediate part of the pile, there is at the boundary division, is subjected to section force, this part increases in size as compared to the pile head in certain instances. Further, we develop a seismic resistance method for a pile foundation in liquefaction using seismic isolation rubber and it is shown the middle part seismic isolation system is very effective.

Evaluation of Bearing Capacity of Strip Foundation Subjected to Eccentric Inclined Loads Using Finite Element Method

Directory of Open Access Journals (Sweden)

Ahmed Majeed Ali

2016-08-01

Full Text Available In real conditions of structures, foundations like retaining walls, industrial machines and platforms in offshore areas are commonly subjected to eccentrically inclined loads. This type of loading significantly affects the overall stability of shallow foundations due to exposing the foundation into two components of loads (horizontal and vertical and consequently reduces the bearing capacity Based on a numerical analysis performed using finite element software (Plaxis 3D Foundation, the behavior of model strip foundation rested on dry sand under the effect of eccentric inclined loads with different embedment ratios (D/B ranging from (0-1 has been explored. The results display that, the bearing capacity of strip foundation is noticeably decreased with the increase of inclination angle (α and eccentricity ratio (e/B. As well as, a reduction factor (RF expression was appointed to measure the degree of decreasing in the bearing capacity when the model footing is subjected to eccentric inclined load. It was observed that, the (RF decreases as the embedment ratio increases. Moreover, the test results also exhibit that, the model footing bearing capacity is reduced by about (69% when the load inclination is varied from (0° to 20° and the model footing is on the surface. While, the rate of decreasing in the bearing capacity was found to be (58%, for both cases of footing when they are at embedment ratios of (0.5 and 1.0. Also, a comparative study was carried out between the present results and previous experimental test results under the same conditions (soil properties and boundary condition. A good agreement was obtained between the predicted bearing capacities for the two related studies.

Response analysis of a nuclear containment structure with nonlinear soil-structure interaction under bi-directional ground motion

Science.gov (United States)

Kumar, Santosh; Raychowdhury, Prishati; Gundlapalli, Prabhakar

2015-06-01

Design of critical facilities such as nuclear power plant requires an accurate and precise evaluation of seismic demands, as any failure of these facilities poses immense threat to the community. Design complexity of these structures reinforces the necessity of a robust 3D modeling and analysis of the structure and the soil-foundation interface. Moreover, it is important to consider the multiple components of ground motion during time history analysis for a realistic simulation. Present study is focused on investigating the seismic response of a nuclear containment structure considering nonlinear Winkler-based approach to model the soil-foundation interface using a distributed array of inelastic springs, dashpots and gap elements. It is observed from this study that the natural period of the structure increases about 10 %, whereas the force demands decreases up to 24 % by considering the soil-structure interaction. Further, it is observed that foundation deformations, such as rotation and sliding are affected by the embedment ratio, indicating an increase of up to 56 % in these responses for a reduction of embedment from 0.5 to 0.05× the width of the footing.

Dynamic Soil-Structure-Interaction

DEFF Research Database (Denmark)

Kellezi, Lindita

1998-01-01

The aim of this thesis is to investigate and develop alternative methods of analyzing problems in dynamic soil-structure-interaction. The main focus is the major difficulty posed by such an analysis - the phenomenon of waves which radiate outward from the excited structures towards infinity....... In numerical calculations, only a finite region of the foundation metium is analyzed and something is done to prevent the outgoing radiating waves to reflect from the regions's boundary. The prosent work concerns itself with the study of such effects, using the finite element method, and artificial...... transmitting boundary at the edges of the computational mesh. To start with, an investigation of the main effects of the interaction phenomena is carried out employing a widely used model, considering dynamic stiffness of the unbounded soil as frequency independent. Then a complete description...

Some Remarks on Foundation Pile Testing Procedures

Science.gov (United States)

Rybak, Jarosław

2017-10-01

This work presents the review of pile capacity testing techniques. In an overview, the key points in pile designing are: determination of the appropriate computational schemes, reliable data on loads and the properties of structural materials (in particular, of the soil mass, which is marked by the greatest variability). The procedure of constructing a pile foundation should include: carrying out soil tests in the scope that ensures safe designing, selecting a piling technology that is relevant both to geotechnical conditions and expected loads, drafting a piling design together with the design of load tests, setting up a testing station for further load tests, static and/or dynamic tests of pile load capacity, preceded by supplementary soil tests when the conditions of test pile installation fail to comply with the design assumptions or when the pile length exceeds the depth of the previously investigated soil, making documentation of load capacity tests (with an additional correction of the piling design), the actual piling (ongoing analysis of pile driving logs and, if necessary, testing the piles’ integrity), drawing up the as-built documentation. Unfortunately, the design is corrected after the load test have been conducted only if the piles fail to show the designed bearing capacity. The designer is then obliged to revise the design assumptions on the basis of tests results. If the test results account for the a greater bearing capacity than necessary and it would be recommendable to limit the extent of the planned (i.e. set out in the contract) piling works, usually neither the contractor nor the designer, nor even the Construction Site Supervisor, acting for the benefit of the Investor, are willing to take on the responsibility for reducing the scope of the piling works. The necessity of conducting additional control tests before and during the implementation of the construction project is often treated by the investors as an attempt at extorting extra

Understanding the soil underfoot: building a national postgraduate soils cohort through participative learning

Science.gov (United States)

Quinton, John; Haygarth, Phil; Black, Helaina; Allton, Kathryn

2015-04-01

Many of the PhD students starting Soil Science PhDs have only a limited understanding of the wider importance of soils, the state -of-art in other sub disciplines, and have often never seen a soil profile in the field. As the number of students nationally in the UK is also small compared to some other disciplines there is also a need to build a cohort of early career researchers. To address these issues, Lancaster University and the James Hutton Institute together with support from the British Society of Soil Science and the Natural Environment Research Council (NERC), ran a 5 day residential foundation soil science 'Summer School' in March 2015. The training school was an intense programme for ambitious and energetic post-graduate students. The course was specifically designed for students who were keen to develop skills in the development of inter-disciplinary research ideas and proposals. Specifically the course addressed: • the different functions in land uses and across landscapes • novel approaches for investigating how soils function • the basics of making a soil description and soil sampling in the field; • the current key challenges in soil science research • the requirements of, and approaches to, soil science research that requires multi-disciplinary and interdisciplinary approaches • the essentials of developing and planning a research project Our approach was to provide a space for the students to both learn from, but also work with some of the leading UK Soil Science experts. We used workshop style lectures, including some delivered via the internet, combined with student research teams working alongside research mentors to produce research proposals to be 'pitched' to a panel at the end of the course. These proposals formed the focus for engagement with the 'experts' making the time the students spent with them concentrated and productive. Feedback from the students was excellent and a variant of the course will be repeated by Cranfield

Analysis of Bearing Capacity Pile Foundation with Using Capwap Software for Testing Pile Driving Analyzer (pda) at Fasfel Development Project Parlimbungan Ketek Sikara-Kara Mandailing Natal District (north Sumatera)

Science.gov (United States)

Oberlyn Simanjuntak, Johan; Suita, Diana

2017-12-01

Pile foundation is one type deep foundation that serves to distribute the load of hard soil structure loading which has a high bearing capacity that is located deep enough inside the soil. To determine the bearing capacity of the pile and at the same time control the Calendring results, the Pile Driving Analyzer (PDA) test at 8 pile sections from the 84 point piling section (10% of the number sections), the results were analyzed by CAPWAP SOFTWARE, and the highest bearing capacity of Ru 177 ton and the lowest bearing capacity of 111 tons, is bigger than the plan load which load plans that is 60,9 tons. Finally the PDA safe is bearing bearing capacity of the load planning.

Applicability of recycled aggregates in concrete piles for soft soil improvement.

Science.gov (United States)

Medeiros-Junior, Ronaldo A; Balestra, Carlos Et; Lima, Maryangela G

2017-01-01

The expressive generation of construction and demolition waste is stimulating several studies for reusing this material. The improvement of soft soils by concrete compaction piles has been widely applied for 40 years in some Brazilian cities. This technique is used to improve the bearing capacity of soft soils, allowing executing shallow foundations instead of deep foundations. The compaction piles use a high volume of material. This article explored the possibility of using recycled aggregates from construction waste to replace the natural aggregates in order to improve the bearing capacity of the soft soil, regarding its compressive strength. Construction wastes from different stages of a construction were used in order to make samples of concrete with recycled aggregates. The strength of concretes with natural aggregates was compared with the strength of concretes with recycled (fine and coarse) aggregates. Results show that all samples met the minimum compressive strength specified for compaction piles used to improve the bearing capacity of soft soils. The concrete with recycled aggregate from the structural stage had even higher resistances than the concrete with natural aggregates. This behaviour was attributed to the large amount of cementitious materials in the composition of this type of concrete. It was also observed that concrete with recycled fine aggregate has a superior resistance to concrete with recycled coarse aggregate.

Establishing a University Foundation.

Science.gov (United States)

Lemish, Donald L.

A handbook on how to establish a university foundation is presented. It presupposes that a foundation will be used as the umbrella organization for receiving all private gifts, restricted and unrestricted, for the benefit of a public college or university; and hence it chiefly addresses readers from public colleges and universities. Information is…

How Saharan Dust Slows River Knickpoints: Coupling Vegetation Canopy, Soils and the Foundation of the Critical Zone

Science.gov (United States)

Brocard, G. Y.; Willenbring, J. K.; Harrison, E. J.; Scatena, F. N.

2015-12-01

Forest succession theory maintains that trees drape existing landscapes as passive niche optimizers, but in the Luquillo Mountains in Puerto Rico, the forest exerts a powerful control on erosion. The Luquillo Critical Zone observatory is set in the Luquillo Mountains, an isolated massif at the northeastern tip of Puerto Rico Island which receives up to five meters of rainfall annually. Most of the rainfall received in the mountains is conveyed as quick flow through soil macropores, inhibiting soil erosion by overland flow. Physical erosion is kept low, occurring in the form of infrequent shallow landslides, thus increasing the residence time of minerals in the near-surface environment. The extensive chemical alteration of minerals generates a thick saprolite covered by fine-grained soil. Over the quartz diorite bedrock that characterizes the southern side of the mountains, the weathering process generates saprolite tens of meters deep that is almost completely devoid of weatherable minerals. Soils forming over this saprolite are nutrient-poor, forcing the rainforest to retrieve its nutrients from atmospheric fluxes, such as Saharan dust and marine aerosols. These atmospheric inputs are thus indirectly essential for the forest to be able to maintain slow erosion rates over the mountains. At lower elevation, using cosmogenic nuclide-derived denudation rates, we identified a wave of incision which has been propagating upstream over the past 4 My in the form of very steep and slowly migrating knickpoints. Bedrock abrasion and plucking are infrequent along the knickpoint faces, because the bedrock is massive and because rivers are bedload-starved. This situation is due to the highly weathered upland soils and slow erosion rates and high weathering rate upstream, which acts to reduce bedload grain size and limits bedload fluxes to the knickpoint, respectively. The soils change radically where the wave of erosion has passed and has increased erosion rates. There, nutrient

Assessing Cross-disciplinary Efficiency of Soil Amendments for Agro-biologically, Economically, and Ecologically Integrated Soil Health Management

Science.gov (United States)

2010-01-01

Preventive and/or manipulative practices will be needed to maintain soil's biological, physiochemical, nutritional, and structural health in natural, managed, and disturbed ecosystems as a foundation for food security and global ecosystem sustainability. While there is a substantial body of interdisciplinary science on understanding function and structure of soil ecosystems, key gaps must be bridged in assessing integrated agro-biological, ecological, economical, and environmental efficiency of soil manipulation practices in time and space across ecosystems. This presentation discusses the application of a fertilizer use efficiency (FUE) model for assessing agronomic, economic, ecological, environmental, and nematode (pest) management efficiency of soil amendments. FUE is defined as increase in host productivity and/or decrease in plant-parasitic nematode population density in response to a given fertilizer treatment. Using the effects of nutrient amendment on Heterodera glycines population density and normalized difference vegetative index (indicator of physiological activities) of a soybean cultivar ‘CX 252’, how the FUE model recognizes variable responses and separates nutrient deficiency and toxicity from nematode parasitism as well as suitability of treatments designed to achieve desired biological and physiochemical soil health conditions is demonstrated. As part of bridging gaps between agricultural and ecological approaches to integrated understanding and management of soil health, modifications of the FUE model for analyzing the relationships amongst nematode community structure, soil parameters (eg. pH, nutrients, %OM), and plant response to soil amendment is discussed. PMID:22736840

Foundations of mechanics

International Nuclear Information System (INIS)

Zorski, Henryk; Bazanski, Stanislaw; Gutowski, Roman; Slawianowski, Jan; Wilmanski, Krysztof; Wozniak, Czeslaw

1992-01-01

In the last 3 decades the field of mechanics has seen spectacular progress due to the demand for applications in problems of cosmology, thermonuclear fusion, metallurgy, etc. This book provides a broad and thorough overview on the foundations of mechanics. It discusses theoretical mechanics and continuum mechanics, as well as phenomenological thermodynamics, quantum mechanics and relativistic mechanics. Each chapter presents the basic physical facts of interest without going into details and derivations and without using advanced mathematical formalism. The first part constitutes a classical exposition of Lagrange's and Hamiltonian's analytical mechanics on which most of the continuum theory is based. The section on continuum mechanics focuses mainly on the axiomatic foundations, with many pointers for further research in this area. Special attention is given to modern continuum thermodynamics, both for the foundations and applications. A section on quantum mechanics is also included, since the phenomenological description of various quantum phenomena is becoming of increasing importance. refs.; figs.; tabs

CARES Foundation

Science.gov (United States)

... Foundation Video Get Involved EMS and Newborn Screening campaigns Clincal trials Fundraisers Support groups Connect and promote with Social Media: Facebook , Twitter , Instagram and LinkedIn News & Notes from ...

Numerical Study of Piping Limits for Suction Installation of Offshore Skirted Foundations an Anchors in Layered Sand

DEFF Research Database (Denmark)

Ibsen, Lars Bo; Thilsted, C. L.

2010-01-01

Skirted foundations and anchors have proved to be competitive solutions for various types of fixed offshore platforms, subsea systems and an attractive foundation alternative for offshore wind turbines. One main design challenge for skirted structures in sand is to penetrate the skirted deep enough...... to obtain the required capacity. In order to overcome the high penetration resistance in sand suction assisted penetration is needed. Suction installation may cause the formation of piping channels, which break down the hydraulic seal and prevent further installation. This paper presents a numerical study...... of failure limits during suction installation in respect to both homogenous and layered soil profile. A numerical flow analysis is performed to determine the hydraulic gradients developing in response to the suction applied, and the results are presented as simple closed form solutions useful for evaluation...

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

Institute of Scientific and Technical Information of China (English)

章香雅; 郑祖祯

2003-01-01

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.

Assessment of seismic wave effects on soil-structure interaction

International Nuclear Information System (INIS)

Bernreuter, D.L.

1977-01-01

One of the most common hypotheses made for soil-structure interaction analyses is that the earthquake input motion is identical at all points beneath the structure. Several papers have recently shown that this assumption may be overly conservative and that the effect of wave passage is extremely important. These studies typically employ a relatively simple model, namely, the basemat is represented by a rectangular rigid foundation resting on top of the soil and connected to the soil by a continuously distributed set of soil springs. The seismic input is applied at the base of the soil springs and is assumed to be traveling at a constant wave velocity across the site. It ispossible to improve on the soil/structure model by use of finite element methods; however, little is known about how to model the input seismic energy and typically a simple travelling wave is used. In this paper, the author examines the available data to determine: (i) the appropriate wave velocity to use, and (ii) if the currently availble analytic models are adequate. (Auth.)

Kinematic seismic response of piles in layered soil profile

International Nuclear Information System (INIS)

Ahmad, I.; Khan, A.N.

2006-01-01

This paper is aimed at highlighting the importance of Kinematic Seismic Response of Piles, a phenomenon often ignored in dynamic analysis. A case study is presented where the end bearing pile is embedded in two layer soil system of highly contrasting stiffnesses; a typical case where kinematic loading plays important role. The pile soil system is modeled as continuous system and as discrete parameter system; both are based on BDWF (Beam on Dynamic Winkler Foundation) formulation. For discrete parameter system, a finite element software SAP2000 is used and the modeling technique of kinematic interaction in finite element software is discussed. For pile soil system modeled as continuous system, a general MATLAB code is developed capable of performing elastic site response analysis in two layer soil system, solving differential equation governing kinematic interaction, and giving as output the maximum ground displacement, maximum pile displacement, rotation, moment and shear distribution along pile length. The paper concludes that kinematic seismic actions must be evaluated particularly at the interface of soil layers of significantly differing soil stiffnesses. (author)

Development and Application of a Numerical Framework for Improving Building Foundation Heat Transfer Calculations

Science.gov (United States)

Kruis, Nathanael J. F.

Heat transfer from building foundations varies significantly in all three spatial dimensions and has important dynamic effects at all timescales, from one hour to several years. With the additional consideration of moisture transport, ground freezing, evapotranspiration, and other physical phenomena, the estimation of foundation heat transfer becomes increasingly sophisticated and computationally intensive to the point where accuracy must be compromised for reasonable computation time. The tools currently available to calculate foundation heat transfer are often either too limited in their capabilities to draw meaningful conclusions or too sophisticated to use in common practices. This work presents Kiva, a new foundation heat transfer computational framework. Kiva provides a flexible environment for testing different numerical schemes, initialization methods, spatial and temporal discretizations, and geometric approximations. Comparisons within this framework provide insight into the balance of computation speed and accuracy relative to highly detailed reference solutions. The accuracy and computational performance of six finite difference numerical schemes are verified against established IEA BESTEST test cases for slab-on-grade heat conduction. Of the schemes tested, the Alternating Direction Implicit (ADI) scheme demonstrates the best balance between accuracy, performance, and numerical stability. Kiva features four approaches of initializing soil temperatures for an annual simulation. A new accelerated initialization approach is shown to significantly reduce the required years of presimulation. Methods of approximating three-dimensional heat transfer within a representative two-dimensional context further improve computational performance. A new approximation called the boundary layer adjustment method is shown to improve accuracy over other established methods with a negligible increase in computation time. This method accounts for the reduced heat transfer

Obtaining corporate information from NHS foundation trusts.

Science.gov (United States)

Woodward, Valerie; Endacott, Ruth; Sheaff, Rod; Jones, Ray

Foundation trusts have boards of directors that are responsible for the day-to-day running of the organisation, planning services and developing strategy. Unlike non-foundation trusts and primary care trusts (PCTs), foundation trusts are not obliged to hold directors' board meetings in public. This article describes the online availability and accessibility of the minutes of such meetings in a number of foundation trusts, non-foundation trusts and PCTs. The implications for transparency in the NHS are also discussed.

Bucket foundations under lateral cyclic loading

DEFF Research Database (Denmark)

Foglia, Aligi

failure envelopes. A jacked installation test is successfully compared with existing models. Tests of bucket foundations under lateral loading applied at different loading rates are analysed. As expected, the bearing capacity of bucket foundations under transient lateral loading increases dramatically...... documents on bearing capacity and installation of bucket foundations are reviewed and the results from the models found in literature are compared to the experimental results obtained in the current study. Monotonic tests of bucket foundations under lateral loading until failure are compared with existing...

The harm of petroleum-polluted soil and its remediation research

Science.gov (United States)

Wang, Shuguang; Xu, Yan; Lin, Zhaofeng; Zhang, Jishi; Norbu, Namkha; Liu, Wei

2017-08-01

Land resources are the foundation of human's survival and development, and it's one of the most valuable natural resources of each country. In view of the serious problems of petroleum pollution to soil caused during the exploration and development processes, this article based on a large number of literature researches, firstly discussed the compositions and properties of petroleum contaminants, secondly investigated some restoration methods for the current situation of petroleum polluted soil, compared and analyzed the advantages and disadvantages of three kinds of bioremediation technologies. Finally, according to the deficiencies of previous research and existing problems, made an outlook of the physical and chemical remediation, bioremediation, and microbe-plant remediation, to provide some enlightenments for petroleum-contaminated soil remediation.

A simplified algorithm for the design of piled raft foundations applied for the case study of a building erected within Żoliborz-Szczęśliwice glacial tunnel valley

Directory of Open Access Journals (Sweden)

Kacprzak Grzegorz

2015-06-01

Full Text Available A common engineering solution for excessive settlement with raft foundation (s is the use of piles in order to reduce the vertical displacements, in this method, the whole structural load is transferred to the piles. This is an overly cautious approach, and there remains a need to find an optimal design method for a building’s foundations. Such a solution may be the piled raft foundation, which allows a reduction of the number of piles due to the integration of the raft in the bearing capacity of the foundation. The aim of the article is to estimate the contribution of foundation elements such as the raft and the piles in the bearing capacity of a residential building located in Warsaw, where the geological conditions are characterized by organic soil layers, principally of gyttja.

49 CFR 230.77 - Foundation brake gear.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall be...

A review of experimental soil-structure interaction damping

International Nuclear Information System (INIS)

Tsai, N.C.

1981-01-01

In soil-structure interaction analysis, the foundation soil is usually represented by impedance springs and dampers. The impedance damping includes the effect of both the material damping and the radiation damping. Because the impedance theory normally assumes a rigid structural base and an elastic bond between the soil and structure, it is generally held that the radiation damping has been overestimated by the theory. There are some published information on the dynamic tests of footings and structures that allow direct or indirect assessments of the validity of the analytical radiation damping. An overview of such information is presented here. Based on these limited test data, it is concluded that for horizontal soil-structure interaction analysis the analytical radiation damping alone is sufficient to represent the combined material and radiation damping in the field. On the other hand, for vertical analysis it appears that the theory may have overestimated the radiation damping and certain reduction is recommended. (orig.)

Industrial Foundations in the Danish Economy

DEFF Research Database (Denmark)

Thomsen, Steen

Industrial Foundations (foundations that own business companies) are found around the world e.g in Northern Europe, Germany, the US and India, but nowhere do they appear to be as economically important as in Denmark. In this paper we review their share of the Danish economy. We find that foundation......-owned companies account for 5-10% of the Danish economy depending on measurement. However, they constitute the bulk of Danish stock market capitalization and R&D expenditure, and they also contribute disproportionally to international business activity. Finally the industrial foundations make charitable donations...

Shrinkage Module of Soil Samples with Different Cement Content

Directory of Open Access Journals (Sweden)

Mohannad Sabry

2017-12-01

Full Text Available The differences in soil's body mass during shrinkage over time have changes in soil physical properties which provide an important reason to check the design of underground foundations in expansive soils. In this paper, a state-of-art of the soil heat stress-strain relationship prediction methods is checked using soil engineering laboratory experiments and Matlab R2013b numerical modelling. The shrinkage of soils with different cement content of (0%, 2%, 4%, 6% and 8% with the same water content of 20 percent in room temperature for 24 hours, are critically reviewed in terms of their predictive shrinkage along with their strengths and flexural behaviour. The review highlights the prediction methods present to determine the effect of heat stress on the shrinkage of soil samples with different cement content after classifying the soils into clay, silt and sand depending on their particle size using sieve and hydrometer experiments. The results of the soil engineering laboratory experiments showed that as the cement content increases, the shrinkage of soil decreases as a result of increased elasticity in soil. The numerical analysis using finite element method in Matlab R2013b shows that as the cement content increases the displacement in the soil sample decreases and that the soil sample with 8% cement content has more resistance to shrinkage and less displacement than the soil with 6% cement, which has less resistance to heat stresses and more displacement.

AAA Foundation for Traffic Safety

Science.gov (United States)

... of Top Deadly Mistakes Made by Teen Drivers -- AAA AAA: Road debris causes avoidable crashes, deaths Save the ... and 500 deaths! Foundation News Stay Tuned New AAA Foundation for Traffic Safety website coming Fall 2017 ...

Foundations of Neuromorphic Computing

Science.gov (United States)

2013-05-01

paradigms: few sensors/complex computations and many sensors/simple computation. Challenges with Nano-enabled Neuromorphic Chips A wide variety of...FOUNDATIONS OF NEUROMORPHIC COMPUTING MAY 2013 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION...2009 – SEP 2012 4. TITLE AND SUBTITLE FOUNDATIONS OF NEUROMORPHIC COMPUTING 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT NUMBER N/A 5c. PROGRAM

Corporate Ownership by Industrial Foundations

DEFF Research Database (Denmark)

Thomsen, Steen

1999-01-01

Industrial foundations are self-governing non profit institutions that own business companies. This ownership structure is found in a fair number of Northern European companies, some of them successful world class competitors. Standard agency theory would predict foundation-owned companies...... to be relatively inefficient since they lack monitoring by residual claimants and access to equity finance from the stock market. Nevertheless, empirical research (Thomsen 1996) has found that Danish foundation-owned companies do no worse in terms of profitability and growth than companies with dispersed ownership...

Experimental and analytical studies for a BWR nuclear reactor building. Evaluation of soil-structure interaction behaviour

International Nuclear Information System (INIS)

Mizuno, N.; Tsushima, Y.

1975-01-01

This paper evaluates the spatial characteristics of dynamic properties, especially soil-structure interaction behaviour, of the BWR nuclear building by experimental and analytical studies. It is well known that the damping effects in soil-structure interaction are remarkable on the building with short periods by the dissipation of vibrational energy to the soil. The authors have previously reported an analytical method for estimating the damping effects the properties of which are characterized as follows: 1) The complex damping is used, because the so-called structural damping may be more suitable for estimating the damping effects of an elastic structure. 2) H. Tajimi's theory is used for estimating the dynamical soil-foundation stiffness with the dissipation of vibrational energy on the elastic half-space soil. In this paper, an approximate explanation is presented in regard to the more developmental mathematical method for estimating the damping effects than the above-mentioned previous method, which is 'Modes Superposition Method for Multi-Degrees of Freedom System' with the constant complex stiffness showing the structural damping effects and the dynamical soil-foundation stiffness approximated by the linear or quadratic functions of the eigenvalues. An approximate explanation is presented in regard to the experimental results of the No. 1 reactor building (BWR) of Hamaoka Nuclear Power Station, The Chubu Electric Power Co., Ltd. (Auth.)

Probabilistic analysis of deformed mode of engineering constructions’ soil-cement grounds

Directory of Open Access Journals (Sweden)

Vynnykov Yuriy

2017-01-01

Full Text Available The results of the analysis of probabilistic methods that are used to assess the deformed state of the foundations of engineering structures are presented. A finite element analysis of the stress-strain state of the “man made soil ground – foundation – structure” system was carried out. A method for probabilistic calculation using the finite element method is proposed. On a real example, the level of reliability of a design decision based on a deterministic calculation is estimated by probabilistic calculation. On the basis of the statistic data obtained by imitational modeling, the probability of failure and no-failure operation of the structure regarding the absolute value of settlement and regarding the value of tilt against the reinforcement ratio of soft soil grounds settlements was determined. The probability of failure regarding the value of tilt against the reinforcement ratio was taken (15 to 25%, which is 0.03 – 0.05.

Wave Forces on Windturbine Foundations

DEFF Research Database (Denmark)

Larsen, Brian Juul; Frigaard, Peter

A testprogramme has been performed to determine the wave forces on two types of foundations for an offshore windturbine. the tested foundation types are a monopile and cone. Furthermore the shaft of the cone has been tested....

Study of Various Techniques for Improving Weak and Compressible Clay Soil under a High Earth Embankment

Directory of Open Access Journals (Sweden)

Zein A.K. M.

2014-04-01

Full Text Available This paper investigates the suitability of three soil improvement techniques for the construction of a high earth embankment on thick weak and highly compressible clay soil. The eastern approach embankment of Alhalfaya Bridge on the River Nile linking Khartoum North and Omdurman cities was chosen as a case study and a comprehensive site investigation program was carried out to determine the properties the subsurface soils. The study results showed that unless the subsurface soils have been improved they may fail or undergo excessively large settlements due to the embankment construction. Three ground improvement techniques based on the principles of the “staged construction method, SCM”, “vertical sand drain, VSD” and “sand compaction piles, SCP” of embankment foundation soil treatment are discussed and evaluated. Embankment design options based on applications of the above methods have been proposed for foundation treatment to adequately support embankment loads. A method performance evaluation based on the improvement of soil properties achieved; the time required for construction and compared estimated costs criteria was made to assess the effectiveness and expected overall performance. Adoption of any of the soil improvement techniques considered depends mainly on the most critical and decisive factor governing the embankment design. Based on the overall performance for the embankment case studied, the sand drains is considered as the most appropriate improvement method followed by the sand compaction piles technique whereas the staged construction method showed the poorest overall performance.

Effect of foundation embedment on the seismic response of a high-temperature gas-cooled reactor plant

International Nuclear Information System (INIS)

Lee, T.H.; Thompson, R.W.; Charman, C.M.

1983-01-01

The effects of soil-structure interaction during seismic events upon the dynamic response of a High Temperature Gas-Cooled Reactor plant (HTGR) have been investigated for both surface-founded and embedded basemats. The influence from foundation embedment has been quantitatively assessed through a series of theoretical studies on plants of various sizes. The surface-founded analyses were performed using frequency-independent soil impedance parameters, while the embedded plant analyses utilized finite element models simulated on the FLUSH computer program. The seismic response of the surface-founded plants has been used to establish the standard-site design in-structure response spectra. These analyses were performed by using the linear modal formulation based on conventional soil stiffness and damping values. They serve as reference solutions to which the response data of the corresponding embedded plants are compared. In these comparison studies the responses of embedded plants were generally found to be lower than those of the corresponding surface-founded plants. Additional studies on the surface-founded plants have recently been performed by considering inelastic soil behavior. These inelastic solutions, which treat the soil as an elasto-plastic medium exhibiting hysteretic unloading-reloading characteristics in time, have reduced the response of surface-founded plants. Numerical results are presented in terms of in-structure response spectra along with other pertinent seismic load data at key levels of the plant. Analysis techniques for future studies using viscoelastic halfspace representation and inelastic finite element modeling for soil are also discussed

The foundation of self-esteem.

Science.gov (United States)

Bailey, Joseph A

2003-05-01

Self-esteem is a simplistic term for varied and complex mental states pertaining to how one views oneself. It takes but little research in the voluminous literature to see the vagueness and inconsistencies in its various definitions. Even more problematic is the uncertainty concerning its foundational components. The importance of having a solid definition and specific ideas about the foundational components of self-esteem is that both pave the way to recognizing its causes; to predicting effects from those causes; and to organizing the trouble-shooting process for locating those philosophical flaws or psychological scars which lead to low self-esteem. The purpose of this paper is to offer a common ground for thinking about self-esteem at its most basic level. In order to distinguish the "basic level" from the rest of the components of self-esteem, let us liken it to a skyscraper building. Here, the focus is on the building's "underground foundation" and the base upon which that foundation rests. The base is a definition that allows for the assessment of the foundation. The underground foundation itself consists of the mental building blocks called self-meaning, self-identity, self-image, and self-concepts. To help illustrate their interactions, a few of the "masks" and "faces" of self-esteem will be mentioned. What is not being addressed is the "above ground structure"--those theories and manifestations dealt with by most mental health specialists.

Unknown foundation determination for scour.

Science.gov (United States)

2012-04-01

Unknown foundations affect about 9,000 bridges in Texas. For bridges over rivers, this creates a problem : regarding scour decisions as the calculated scour depth cannot be compared to the foundation depth, and a : very conservative costly approach m...

Foundational aspects of security

DEFF Research Database (Denmark)

Chatzikokolakis, Konstantinos; Mödersheim, Sebastian Alexander; Palamidessi, Catuscia

2014-01-01

This Special Issue of the Journal of Computer Security focuses on foundational aspects of security, which in recent years have helped change much of the way we think about and approach system security.......This Special Issue of the Journal of Computer Security focuses on foundational aspects of security, which in recent years have helped change much of the way we think about and approach system security....

Marfan Foundation

Science.gov (United States)

... The Marfan Foundation Marfan & Related Disorders What is Marfan Syndrome? What are Related Disorders? What are the Signs? ... Click to see what's happening around the country! Marfan syndrome is a life-threatening genetic disorder, and an ...

Vasculitis Foundation

Science.gov (United States)

... Our Board Our Team Anniversary Vasculitis Foundation Newsletters Annual Reports Press Page Literature Order Form Join Contact Us Dream Big Donate Donate Support the VF Through the Amazon Smile Program United Way Giving Ways to Give ...

Effects of Biochar and Lime on Soil Physicochemical Properties and Tobacco Seedling Growth in Red Soil

Directory of Open Access Journals (Sweden)

ZHU Pan

2015-12-01

Full Text Available Red soil, mainly found in the southern China, is developed in a warm, moist climate. The main property of the soils is strong acidity, aluminum toxicity, and low available nutrients. In this study, different effects of biochar and lime on soil physicochemical properties and tobacco growth were determined in red soil, so as to provide a scientific foundation for soil improvement tobacco field. A pot experiment was designed and conducted at four biochar levels(0, 0.5%, 1%, 2% and normal lime level (0.3% to study effects of two different soil amendments on red soil pH, exchangeable aluminum(Exc-Al and exchangeable manganese(Exc-Mn, available nutrients and organic carbon (SOC. Meanwhile, agronomic traits, biomass and leaves elements of tobacco were also tested. Results showed that the agronomic characters and biomass of tobacco seedling had changed effectively after biochar or lime was added. Under 0.5%, 1% biochar treatment, the content of nitrogen(N, phosphorus(P, potassium(K, calcium(Ca and magnesium(Mg in tobacco leaves substantially raised. However, when 2% biochar was applied, leaves N content declined by 9.3%. Compared with the control, leaves N, P and Ca content increased observably in the lime treatment. However, its K and Mg content decreased by 9.0% and 13.3% respectively. Alkaline nitrogen(SAN, available phosphorus (SAP, available potassium (SAK, and exchangeable calcium (Exc-Ca and exchangeable magnesium (Exc-Mg were improved obviously in soil applied with biochar. Only the content of Exc-Ca was significantly increased in lime treatment. In addition, it was beneficial to improve soil pH and reduce soil Exc-Al when biochar or lime had been used. Thus, both biochar and lime are propitious to increase soil pH value, lessen soil Exc-Al content, and improve the growth of tobacco seedling. Furthermore, biochar application also can raise the content of available nutrient and SOC in red soil.

INTERACTION OF SOIL-CEMENT PILE SUPPORTING STRUCTURES WITH THE BODY OF A LANDSLIDE

Directory of Open Access Journals (Sweden)

D. Y. Ihnatenko

2017-10-01

Full Text Available Purpose. Analysis and comparison of the landslide slope finite element model calculation results of the appliance of soil-cement piles, depending on the variation of the retaining structure rigidity, makes it possible to evaluate the effectiveness of their application and the cooperative work of piles with the displacement body. It also makes it possible to make a conclusion about the advantages of using this anti-landslide protection method of the slope. Methodology. Analysis of geomorphological data obtained from the results of laboratory studies of soils on the slope section is considered. Creation of a three-dimensional finite-element slope model according to the constructed sections and depths of the soil layers. Calculation of the nonlinear problem of finite element modeling of the slope with applying of soil-cement piles of various rigidity. Findings. The obtained results of calculating the finite element model of the landslide slope, and the analysis of the stress-strain state of the construction with soil-cement piles has been carried out. Originality. Despite the widespread of using soil-cement piles as enclosing structures for the construction of foundation pits and reinforcement of foundations of emergency structures, special attention should be paid to the study of the expediency of using soil-cement retaining pile structures on landslide areas. Practical value. It is known that soil-cement retaining piles are expediently in use as a protective element, which interacts quite well with the ground environment due to its structure of the initial material. Using of modern computer programs of finite element modeling makes it possible to calculate the efficiency of the use of soil-cement piles and to determine the parameters of the necessary retaining structure according to the given geological structure of the slope, and also, depending on its shape and the physical characteristics of the soils, to compare the performance of different

Characteristics of Soil Structure Interaction for Reactor Building of Kashiwazaki-Kariwa Nuclear Power Plant

International Nuclear Information System (INIS)

Gil, Moon Joo; Jung, Rae Young; Hyun, Chang Hun; Kim, Moon Soo; Lim, Nam Hyoung

2010-01-01

On 16 July 2007, the Nigataken-chuetsu-oki earthquake registering a moment magnitude of 6.8 occurred at a depth of about 15 km. As a result of this earthquake, noticeable shaking exceeding the design ground motion was measured at the Tokyo Electric Power Company (TEPCO) Kashiwazaki-Kariwa Nuclear Power Station (KKN), the biggest nuclear power plant in the world, located at about 16 km away from the epicenter. This earthquake triggered a fire at an electrical transformer and insignificant damage on some parts of facilities. This event gave an impulse to study on the damage and safety margin of nuclear power plant due to the strong earthquake exceeding design basis. As a part of those efforts, KARISMA (KAshiwazaki-Kariwa Research Initiative for Seismic Margin Assessment) benchmark study was launched by the IAEA in terms of an international collaborative research. The main objectives of this research are to estimate the structural behavior and to evaluate the seismic margin of reactor building considering the effects of Soil-Structure Interaction (SSI). This paper presents verification of structural model developed here and validation of soil foundation characteristics through soil-column analysis. It has also been demonstrated that the spring constants and damping coefficient obtained from impedance analysis represent well the soil foundation characteristics

Healthy sand : a farmers initiative on soil protection and ecosystem service management

Science.gov (United States)

Smit, Annemieke; Verzandvoort, Simone; Kuikman, Peter; Stuka, Jason; Morari, Francesco; Rienks, Willem; Stokkers, Jan; Hesselink, Bertus; Lever, Henk

2015-04-01

In a small region in the Netherlands a group of dairy farmers (cooperated in a foundation HOE Duurzaam) cooperates with the drinking water company and together aim for a more healthy soil. They farm a sandy soil, which is in most of the parcels low in organic matter. The local farmers perceive loss of soil fertility and blame loss of soil organic matter for that. All farmers expect that increasing the soil organic matter content will retain more nitrates in the soil, leading to a reduction in nitrate leaching and a higher nutrient availability for the crops, forage and grass and probably low urgency for grassland renewal. The drinking water company in the area also has high expectations that a higher SOM content does relate to higher quality of the (drinking) water and lower costs to clean and filter the water to meet drinking water quality requirements. Most farmers in the area face suboptimal moisture conditions and thrive for increasing the soil organic matter content and improving the soil structure as key factors to relieve, soil moisture problems both in dry (drought) and wet (flooding) periods. A better water holding capacity of the soil provides benefits for the regional water board as this reduces leaching and run-off. The case study, which is part of the Recare-project, at first glance deals with soil management and technology to improve soil quality. However, the casus in fact deals with social innovation. The real challenge to this group of neighbours, farmers within a small region, and to science is how to combine knowledge and experience on soil management for increasing the content of soil organic matter and how to recognize the ecosystem services that are provided by the adapted and more 'healthy' soils. And also how to formalize relations between costs and benefits of measures taken in the field and how these could be financially rewarded from an agreed and acceptable financial awarding scheme based on payments for securing soil carbon stocks and

Three Dimensional Response Spectrum Soil Structure Modeling Versus Conceptual Understanding To Illustrate Seismic Response Of Structures

International Nuclear Information System (INIS)

Touqan, Abdul Razzaq

2008-01-01

Present methods of analysis and mathematical modeling contain so many assumptions that separate them from reality and thus represent a defect in design which makes it difficult to analyze reasons of failure. Three dimensional (3D) modeling is so superior to 1D or 2D modeling, static analysis deviates from the true nature of earthquake load which is ''a dynamic punch'', and conflicting assumptions exist between structural engineers (who assume flexible structures on rigid block foundations) and geotechnical engineers (who assume flexible foundations supporting rigid structures). Thus a 3D dynamic soil-structure interaction is a step that removes many of the assumptions and thus clears reality to a greater extent. However such a model cannot be analytically analyzed. We need to anatomize and analogize it. The paper will represent a conceptual (analogical) 1D model for soil structure interaction and clarifies it by comparing its outcome with 3D dynamic soil-structure finite element analysis of two structures. The aim is to focus on how to calculate the period of the structure and to investigate effect of variation of stiffness on soil-structure interaction

The experience of strengthening subsidence of the soil under the existing building in the city of Rostov-on-Don

Directory of Open Access Journals (Sweden)

Prokopov Albert

2017-01-01

Full Text Available Described problem for multi-storey residential development in the city of Rostov-on-Don on collapsible soils. The analysis of the technical and technological peculiarities of solidification under conditions of maintained buildings. Examples of projects of consolidation subsidence of foundation soils of buildings in operation 50–70 years.

Numerical investigation of soil and buried structures using finite element analysis

Directory of Open Access Journals (Sweden)

Meysam Shirzad Shahrivar

2017-02-01

Full Text Available Today the important of studying soil effect on behavior of soil  contacted structures such as foundations, piles,  retaining wall and other similar structures is so much that neglecting of soil-structure interaction effect can cause to untrue results. In this paper soil-structure interaction simulation was done by using Finite element method analysis with ABAQUS version 6.13-14.The results has been presented based on pile function in contact with soil, vertical stresses in soil and structures, pore pressure in drained and undrained condition and underground water level.Final conclusions revealed that pore pressure effect is not uniform on all parts of pile and amount of pore pressure increment in top elements is lower than down elements of  pile.Further it was proven that average amount of vertical stress on end of pile is    of this stress on top of the pile. thus it was concluded that 70% of pile bearing capacity is depend on friction of soil and pile contact surface.

Assessment of soil-structure interaction effects based on simple modes

International Nuclear Information System (INIS)

Philippacopoulos, A.J.; Miller, C.A.

1983-01-01

Soil-structure interaction effects are investigated using a simple mathematical model which employs three degrees-of-freedom. The foundation is approximated by a homogeneous, isotropic, elastic half-space. Harmonic functions and a recorded earthquake are used to represent the free-field input motion. Variations of the response characteristics due to structural and interaction parameters are demonstrated. Response spectra are presented that display the magnitude of the maximum structural response for a range of fixed-base structural frequencies, interaction frequencies and damping. Conclusions are obtained regarding the behavior of the response of the soil-structure system. The findings reported herein can be used for the interpretation of the results of soil-structure interaction analyses of nuclear plant structures that are performed with available computer codes

Safety assessment of a shallow foundation using the random finite element method

Science.gov (United States)

Zaskórski, Łukasz; Puła, Wojciech

2015-04-01

A complex structure of soil and its random character are reasons why soil modeling is a cumbersome task. Heterogeneity of soil has to be considered even within a homogenous layer of soil. Therefore an estimation of shear strength parameters of soil for the purposes of a geotechnical analysis causes many problems. In applicable standards (Eurocode 7) there is not presented any explicit method of an evaluation of characteristic values of soil parameters. Only general guidelines can be found how these values should be estimated. Hence many approaches of an assessment of characteristic values of soil parameters are presented in literature and can be applied in practice. In this paper, the reliability assessment of a shallow strip footing was conducted using a reliability index β. Therefore some approaches of an estimation of characteristic values of soil properties were compared by evaluating values of reliability index β which can be achieved by applying each of them. Method of Orr and Breysse, Duncan's method, Schneider's method, Schneider's method concerning influence of fluctuation scales and method included in Eurocode 7 were examined. Design values of the bearing capacity based on these approaches were referred to the stochastic bearing capacity estimated by the random finite element method (RFEM). Design values of the bearing capacity were conducted for various widths and depths of a foundation in conjunction with design approaches DA defined in Eurocode. RFEM was presented by Griffiths and Fenton (1993). It combines deterministic finite element method, random field theory and Monte Carlo simulations. Random field theory allows to consider a random character of soil parameters within a homogenous layer of soil. For this purpose a soil property is considered as a separate random variable in every element of a mesh in the finite element method with proper correlation structure between points of given area. RFEM was applied to estimate which theoretical

Seismic isolation of two dimensional periodic foundations

International Nuclear Information System (INIS)

Yan, Y.; Mo, Y. L.; Laskar, A.; Cheng, Z.; Shi, Z.; Menq, F.; Tang, Y.

2014-01-01

Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5 Hz to 50 Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.

Monitoring the southwestern Wyoming landscape—A foundation for management and science

Science.gov (United States)

Manier, Daniel J.; Anderson, Patrick J.; Assal, Timothy J.; Chong, Geneva W.; Melcher, Cynthia P.

2017-08-29

Natural resource monitoring involves repeated collections of resource condition data and analyses to detect possible changes and identify underlying causes of changes. For natural resource agencies, monitoring provides the foundation for management and science. Specifically, analyses of monitoring data allow managers to better understand effects of land-use and other changes on important natural resources and to achieve their conservation and management goals. Examples of natural resources monitored on public lands include wildlife habitats, plant productivity, animal movements and population trends, soil chemistry, and water quality and quantity. Broader definitions of monitoring also recognize the need for scientifically valid data to help support planning efforts and informed decisions, to develop adaptive management strategies, and to provide the means for evaluating management outcomes.

Improved soil characterization for pipe piles in sand in API RP-2A

International Nuclear Information System (INIS)

Hossain, M.K.; Briaud, J.L.

1993-01-01

In the offshore, most foundations are steel pipe piles and most of them are designed using the API RP 2A guidelines. For axial capacity of piles in sand the current guidelines in many cases show definite discrepancies when compared against actual load capacities of piles. An updated data base analysis shows that there are three major weaknesses in the current guidelines with respect to soil characterization: (a) the consideration of the lateral earth pressure coefficient, K, as a constant (1.0 or 0.8); (b) the consideration of the unit point bearing resistance, q, as a linear function of depth; and (c) the absence of an unambiguous soil parameter determination process based on reliable in-situ test results. In this paper, specific modifications to the current API RP 2A guidelines are proposed on the basis of a data base analysis to account for the discrepancies arising from (a), (b), and (c) above. These modifications will reduce the discrepancies in the current API RP 2A method and increase the accuracy of the prediction of axial capacity of pipe piles in sand. Furthermore this will make the method fundamentally more consistent with soil behavior in deep foundations

Geotechnical zoning of urban foundations: Avilés case study (N Spain)

Science.gov (United States)

María Díaz-Díaz, Luis; Arias, Daniel; López-Fernández, Carlos; Pando, Luis

2014-05-01

on their foundation conditions: i) good ground conditions (rocks: UCS > 25 MPa); ii) acceptable ground conditions (rocks: UCS 5-25 MPa); iii) bad ground conditions (soils and rocks: UCS edification, being useful to society, industrial and public sectors.

Canonical discrimination of the effect of a new broiler production facility on soil chemical profiles as related to current management practices

Science.gov (United States)

The effect dirt-floored broiler houses have on the underlying native soil and the potential for contamination of the ground water by leaching under the foundation of these houses is an understudied area. No research could be found in the literature which followed alterations in soil parameters from...

Near-field soil-structure interaction analysis using nonlinear hybrid modeling

International Nuclear Information System (INIS)

Katayama, I.; Chen, C.; Lee, Y.J.; Jean, W.Y.; Penzien, J.

1989-01-01

The hybrid modeling method (Gupta and Penzien 1980) and associated analysis procedure for solving a three-dimensional soil-structure interaction problem was developed by Gupta and Penzien (1981) and Gupta et al.(1982). Subsequently, successive modifications have been made to the original modeling method and analysis procedure allowing more general treatment of the SSI problem (Penzien, 1988). Through many correlation studies of field test data obtained under forced-vibration and earthquake-excitation conditions, it has been shown that the HASSI programs can effectively predict the dynamic response of a soil-structure system, if realistic soil parameters are adopted. In the above, the entire structure-foundation system is considered to respond in a linear fashion. Since the reflected three-dimensional waves at the soil-structure interface decays very rapidly with distance away from the structure (Katayama, 1987 (a)), the response of the soil close to the base of the structure may greatly affect its response; therefore, proper modeling of the non-linear soil behavior characteristic is essential. The nonlinear behavior of near-field soil has been taken into consideration in HASSI-7 by the standard equivalent linearization procedures used in programs SHAKE and FLUSH

Theodore Presser and His Foundation.

Science.gov (United States)

Nazzaro, William J.

1983-01-01

Describes the life of Theodore Presser and the establishment of the Presser Foundation in 1916. Presser was a music publisher and the founder of "Etude" magazine. The Presser Foundation provides scholarships to music students, aid to elderly music teachers, and help to colleges for building music facilities. (CS)

Profiles of Nine Community Colleges with Successful Foundations.

Science.gov (United States)

Angel, Dan; Gares, Dale

1981-01-01

College profiles include the following information: type of college, location, enrollment, age of college, total budget, foundation's years of experience, non-profit status, total foundation assets, dollar support for 1979-80, responsibility for foundation, number of foundation board members, most successful fund-raising methods, and restrictions…

Three dimensional periodic foundations for base seismic isolation

International Nuclear Information System (INIS)

Yan, Y; Mo, Y L; Cheng, Z; Shi, Z; Menq, F; Tang, Y

2015-01-01

Based on the concept of phononic crystals, periodic foundations made of periodic materials are investigated in this paper. The periodic foundations can provide low frequency band gaps, which cover the main frequency ranges of seismic waves. Therefore, the periodic foundations are able to protect the upper structures during earthquake events. In this paper, the basic theory of three dimensional periodic foundations is studied and the finite element method was used to conduct the sensitivity study. A simplified three-dimensional periodic foundation with a superstructure was tested in the field and the feasibility of three dimensional periodic foundations was proved. The test results showed that the response of the upper structure with the three dimensional periodic foundation was reduced under excitation waves with the main frequency falling in the attenuation zones. The finite element analysis results are consistent with the experimental data, indicating that three dimensional periodic foundations are a feasible way of reducing seismic vibrations. (paper)

Experimental study on embedment effect of foundation, 2

International Nuclear Information System (INIS)

Ohtomo, Keizo; Toma, Junichi; Hashimoto, Koichi; Hanada, Kazutake; Ueshima, Teruyuki; Yajima, Hiroshi

1986-01-01

In order to make clear the dynamic behavior of a embeded foundation on the quarternary ground experimentally, a series of forced vibration tests and seismic observation on both the small foundation (4 x 4 x 3 m) and the embeded form larger scale foundation of the shaking table (16 x 16 x 7.7 m) were conducted at the same site. The purposes this study are evaluating the dynamic behavior and the characteristics of dynamic stiffness and damping of the larger foundation based on forced vibration tests, and applying them to the dynamic response analysis of variable embedded foundations. In this report, the authors first examine frequency dependent property and its theoretical tendency of dynamic stiffness and damping surrounding table foundation. And then, consider an applicability and point of discussion related with the some theories which influence the embedment effect, in contrast with the experimental datum of the model foundation are past studies on a embedment effect (JPDR, Large-Scale Foundation in Tadotsu). (author)

Polish Foundation for Energy Efficiency

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

The Polish Foundation for Energy Efficiency (FEWE) was established in Poland at the end of 1990. FEWE, as an independent and non-profit organization, has the following objectives: to strive towards an energy efficient national economy, and to show the way and methods by use of which energy efficiency can be increased. The activity of the Foundation covers the entire territory of Poland through three regional centers: in Warsaw, Katowice and Cracow. FEWE employs well-known and experienced specialists within thermal and power engineering, civil engineering, economy and applied sciences. The organizer of the Foundation has been Battelle Memorial Institute - Pacific Northwest Laboratories from the USA.

Assessment of seismic wave effects on soil-structure interaction

International Nuclear Information System (INIS)

Bernreuter, D.L.

1977-03-01

It is normally assumed in the seismic analysis of structures that the free-field motion which is used as input is the same for all points on a given level beneath the foundation mat. This represents a simplification, as not all particles of soil describe the same motion simultaneously. As the foundation mat of the structure is rigid in the horizontal direction, it will tend to average the ground motion. Abandoning the assumption of the uniformity of the input motion may lead to a reduction of the translational motion which a foundation mat will experience, as the displacement components will cancel each other to a certain extent. This is of considerable interest for the design of nuclear power plants which are very stiff, large structures. To investigate these effects, the extremely complex phenomenon of the passage of a seismic wave has to be simplified considerably. It is the purpose of this paper to determine if wave passage effects can be determined from the simplified analyses currently used

KIN SP: A boundary element method based code for single pile kinematic bending in layered soil

Directory of Open Access Journals (Sweden)

Stefano Stacul

2018-02-01

Full Text Available In high seismicity areas, it is important to consider kinematic effects to properly design pile foundations. Kinematic effects are due to the interaction between pile and soil deformations induced by seismic waves. One of the effect is the arise of significant strains in weak soils that induce bending moments on piles. These moments can be significant in presence of a high stiffness contrast in a soil deposit. The single pile kinematic interaction problem is generally solved with beam on dynamic Winkler foundation approaches (BDWF or using continuous models. In this work, a new boundary element method (BEM based computer code (KIN SP is presented where the kinematic analysis is preceded by a free-field response analysis. The analysis results of this method, in terms of bending moments at the pile-head and at the interface of a two-layered soil, are influenced by many factors including the soil–pile interface discretization. A parametric study is presented with the aim to suggest the minimum number of boundary elements to guarantee the accuracy of a BEM solution, for typical pile–soil relative stiffness values as a function of the pile diameter, the location of the interface of a two-layered soil and of the stiffness contrast. KIN SP results have been compared with simplified solutions in literature and with those obtained using a quasi-three-dimensional (3D finite element code.

Use of the laboratory tests of soil modulus in modelling pile behaviour

Science.gov (United States)

Dyka, Ireneusz

2012-10-01

This article deals with the question of theoretical description of behaviour of a single pile rested in a layered soil medium. Particular attention is paid to soil modulus which is used in calculation method for pile load-settlement curve. A brief analysis of the results obtained by laboratory tests to assess soil modulus and its nonlinear variability has been presented. The results of tests have been used in triaxial apparatus and resonant column/torsional shear device. There have also been presented the results of load-settlement calculation for a single pile under axial load with implementation of different models of soil modulus degradation. On this basis, possibilities of using particular kinds of laboratory tests in calculation procedure of foundation settlement have been presented as well as further developments of them.

Foundation Networks and American Hegemony

Directory of Open Access Journals (Sweden)

Inderjeet Parmar

2012-02-01

Full Text Available The major American foundations constructed and sustained the rich texture of cooperative social, intellectual and political relations between key actors and institutions supportive of specific modes of thought that promoted US hegemony. Foundations also fostered and developed the attractive power-knowledge networks that not only radiated intellectual influence but also attracted some of the most creative minds. Finally, liberal internationalist foundations fostered globalism even when the American state was ‘isolationist’, and when US influence abroad unwelcome. Their significance in American hegemony building lay in their sustained, long-term cooperative relationship with the American state through which they helped build national, international and global institutions and networks. The latter process evidences the most significant impact of US foundations – the building of the domestic and international infrastructure for liberal internationalism which has transformed into a kind of “social neoliberalism”. Theoretical conclusions follow from these claims: the sustained and deep cooperation between the state and foundations suggests that we must revise our views of “how power works” in the United States and therefore influences its foreign relations. Therefore, the article shows that elite networks, consisting of state officials and private citizens are powerful means by which foreign policy shifts may be prepared, elite and mass opinion primed and mobilised, new consensus built, ‘old’ forces marginalised, and US hegemony constructed.

The Foundation Handbook: A Private Foundation Approach to Fund Raising at State Colleges and Universities.

Science.gov (United States)

Lemish, Donald L.

Guidelines for state colleges and universities who wish to use a foundation as an umbrella organization for receiving all private gifts, restricted and unrestricted, are presented. In examining the need for a foundation, attention should be directed to: establishing credibility, marshalling volunteers, providing for a mechanism for accepting life…

Arthritis Foundation

Science.gov (United States)

... Vision Leadership News Partners & Sponsors Careers Code of Ethics Financials Annual Report Contact Us Privacy Policy Terms & Conditions Donate Press Store Blog Community Local Offices Kids Get Arthritis Too Español Arthritis Today Social Media Newsletters Sign Up for E-Newsletters Arthritis Foundation ...

Integrating biological indicators in a Soil Monitoring Network (SMN to improve soil quality diagnosis - a case study in Southern Belgium (Wallonia

Directory of Open Access Journals (Sweden)

Krüger, I.

2017-01-01

Full Text Available Description of the subject. Soil organisms and their activities are essential for soil ecosystem functioning and they can thus be used as pertinent indicators of soil quality. Recent efforts have been undertaken to include biological indicators of soil quality into regional/national monitoring networks. Objectives. The aim of this study was to provide a first dataset of six biological indicators and two eco-physiological quotients for two landscape units in Wallonia. These spatial units are characterized by homogeneous climate conditions, soil type, land-use and management (here, grasslands in the Ardennes, and croplands in the Loam Region. Method. Respiration potential, microbial biomass carbon and nitrogen, net nitrogen mineralization, metabolic potential of soil bacteria and earthworm abundance were measured at a total of 60 sites in two different landscape units (LSU. Variability within each LSU was studied. Data was synthesized through calculation of a comprehensive score and presentation as radar plots. Results. All selected biological indicators were significantly higher under grassland than under cropland soils, highlighting the biological indicators' power of discrimination between main land use types. Variability within LSU depended on the biological indicator and was generally higher in grassland than in cropland soils. Each site could unambiguously be assigned to its landscape unit based on its calculated comprehensive score. Radar plots allowed an assessment of the distribution of values within a landscape unit at a glance. Conclusions. The pilot-study defined the first baseline values for agricultural soils in Wallonia and laid the foundation for a monitoring network of biological soil quality.

Signature Pedagogies for Social Foundations: Negotiating Social Foundations Teaching Practices in the Field of Education

Science.gov (United States)

Schneider, Sandra B.

2010-01-01

The conflicts arising between the pedagogical preferences of the fields of instructional design and technology (IDT) and social foundations of education are substantial. This conflict is primarily one of pedagogical values separating the Social Foundations with its emphasis on critical and creative thinking and the presumption of value and theory…

Soil Organic Matter Stability and Soil Carbon Storage with Changes in Land Use Intensity in Uganda

Science.gov (United States)

Tiemann, L. K.; Grandy, S.; Hartter, J.

2014-12-01

As the foundation of soil fertility, soil organic matter (SOM) formation and break-down is a critical factor of agroecosystem sustainability. In tropical systems where soils are quickly weathered, the link between SOM and soil fertility is particularly strong; however, the mechanisms controlling the stabilization and destabilization of SOM are not well characterized in tropical soils. In western Uganda, we collected soil samples under different levels of land use intensity including maize fields, banana plantations and inside an un-cultivated native tropical forest, Kibale National Park (KNP). To better understand the link between land use intensity and SOM stability we measured total soil C and N, and respiration rates during a 369 d soil incubation. In addition, we separated soils into particle size fractions, and mineral adsorbed SOM in the silt (2-50 μm ) and clay (fractions was dissociated, purified and chemically characterized via pyrolysis-GC/MS. Cultivated soil C and N have declined by 22 and 48%, respectively, in comparison to uncultivated KNP soils. Incubation data indicate that over the last decade, relatively accessible and labile soil organic carbon (SOC) pools have been depleted by 55-59% in cultivated soils. As a result of this depletion, the chemical composition of SOM has been altered such that clay and silt associated SOM differed significantly between agricultural fields and KNP. In particular, nitrogen containing compounds were in lower abundance in agricultural compared to KNP soils. This suggests that N depletion due to agriculture has advanced to pools of mineral associated organic N that are typically protected from break-down. In areas where land use intensity is relatively greater, increases in polysaccharides and lipids in maize fields compared to KNP indicate increases in microbial residues and decomposition by-products as microbes mine SOM for organic N. Chemical characterization of post-incubation SOM will help us better understand

Moral foundations vignettes: a standardized stimulus database of scenarios based on moral foundations theory.

Science.gov (United States)

Clifford, Scott; Iyengar, Vijeth; Cabeza, Roberto; Sinnott-Armstrong, Walter

2015-12-01

Research on the emotional, cognitive, and social determinants of moral judgment has surged in recent years. The development of moral foundations theory (MFT) has played an important role, demonstrating the breadth of morality. Moral psychology has responded by investigating how different domains of moral judgment are shaped by a variety of psychological factors. Yet, the discipline lacks a validated set of moral violations that span the moral domain, creating a barrier to investigating influences on judgment and how their neural bases might vary across the moral domain. In this paper, we aim to fill this gap by developing and validating a large set of moral foundations vignettes (MFVs). Each vignette depicts a behavior violating a particular moral foundation and not others. The vignettes are controlled on many dimensions including syntactic structure and complexity making them suitable for neuroimaging research. We demonstrate the validity of our vignettes by examining respondents' classifications of moral violations, conducting exploratory and confirmatory factor analysis, and demonstrating the correspondence between the extracted factors and existing measures of the moral foundations. We expect that the MFVs will be beneficial for a wide variety of behavioral and neuroimaging investigations of moral cognition.

Moral foundations vignettes: a standardized stimulus database of scenarios based on moral foundations theory

Science.gov (United States)

Iyengar, Vijeth; Cabeza, Roberto; Sinnott-Armstrong, Walter

2016-01-01

Research on the emotional, cognitive, and social determinants of moral judgment has surged in recent years. The development of moral foundations theory (MFT) has played an important role, demonstrating the breadth of morality. Moral psychology has responded by investigating how different domains of moral judgment are shaped by a variety of psychological factors. Yet, the discipline lacks a validated set of moral violations that span the moral domain, creating a barrier to investigating influences on judgment and how their neural bases might vary across the moral domain. In this paper, we aim to fill this gap by developing and validating a large set of moral foundations vignettes (MFVs). Each vignette depicts a behavior violating a particular moral foundation and not others. The vignettes are controlled on many dimensions including syntactic structure and complexity making them suitable for neuroimaging research. We demonstrate the validity of our vignettes by examining respondents’ classifications of moral violations, conducting exploratory and confirmatory factor analysis, and demonstrating the correspondence between the extracted factors and existing measures of the moral foundations. We expect that the MFVs will be beneficial for a wide variety of behavioral and neuroimaging investigations of moral cognition. PMID:25582811

Analysis of soil-structure interaction and floor response spectrum of reactor building for China advanced research reactor

International Nuclear Information System (INIS)

Rong Feng; Wang Jiachun; He Shuyan

2006-01-01

Analysis of Soil-Structure Interaction (SSI) and calculation of Floor Response Spectrum (FRS) is substantial for anti-seismic design for China Advanced Research Reactor (CARR) project. The article uses direct method to analyze the seismic reaction of the reactor building in considering soil-structure interaction by establishing two-dimensional soil-structure co-acting model for analyzing and inputting of seismic waves from three directions respectively. The seismic response and floor response spectrum of foundation and floors of the building under different cases have been calculated. (authors)

Optimum Design of Braced Steel Space Frames including Soil-Structure Interaction via Teaching-Learning-Based Optimization and Harmony Search Algorithms

OpenAIRE

Ayse T. Daloglu; Musa Artar; Korhan Ozgan; Ali İ. Karakas

2018-01-01

Optimum design of braced steel space frames including soil-structure interaction is studied by using harmony search (HS) and teaching-learning-based optimization (TLBO) algorithms. A three-parameter elastic foundation model is used to incorporate the soil-structure interaction effect. A 10-storey braced steel space frame example taken from literature is investigated according to four different bracing types for the cases with/without soil-structure interaction. X, V, Z, and eccentric V-shaped...

Experimental and analytical studies for a BWR nuclear reactor building evaluation of soil-structure interaction behavior

International Nuclear Information System (INIS)

Mizuno, N.; Tsushima, Y.

1975-01-01

The purpose of this paper is to evaluate the spatial characteristics of dynamic properties, especially soil-structure interaction behavior, or the BWR nuclear reactor building by experimental and analytical studies. An analytical method (SMIRT-1 Paper K 2/4) for estimating the damping effects is reported. The complex damping is used, because the so-called structural damping may be more suitable for estimating the damping effects of an elastic structure. H. Tajimi's theory is used for estimating the dynamical soil-foundation stiffness with the dissipation of vibrational energy on the elastic half-space soil. An approximate explanation is presented in regard to the more developmental mathematical method for estimating the damping effects than the above-mentioned previous method, which is 'Modes Superposition Method for Multi-Degrees of Freedom System' with the constant complex stiffness showing the structural damping effects and the dynamical soil-foundation stiffness approximated by the linear or quadratic functions of the eigenvalues. Next, an approximate explanation is presented in regard to the experimental results of the No.1 reactor building (BWR) of Hamaoka Nuclear Power Station, The Chubu Electric Power Co., Ltd. The regression analyses of the experimental resonance curves by one degree system show that the critical damping ratio is larger than the 0.10 used in the design for the fundamental natural period. It is attempted to simulate the experimental results by the above-mentioned method. The simulated model is a fourty-eight degrees of freedom spring mass system because of the eight masses for the eight floors including the base foundation and the six degrees of freedom for a mass

Foundations for the Future: The Fundraising Role of Foundation Boards at Public Colleges and Universities

Science.gov (United States)

Worth, Michael

2012-01-01

In the face of rising costs and a prolonged economic downturn, public colleges and universities are being challenged to increase their sources of private support and philanthropy. Drawing on the findings of a recent AGB survey of public college- and university-affiliated foundation board chairs and chief executive officers, Foundations for the…

Wronski's Foundations of Mathematics.

Science.gov (United States)

Wagner, Roi

2016-09-01

Argument This paper reconstructs Wronski's philosophical foundations of mathematics. It uses his critique of Lagrange's algebraic analysis as a vignette to introduce the problems that he raised, and argues that these problems have not been properly appreciated by his contemporaries and subsequent commentators. The paper goes on to reconstruct Wronski's mathematical law of creation and his notions of theory and techne, in order to put his objections to Lagrange in their philosophical context. Finally, Wronski's proof of his universal law (the expansion of a given function by any series of functions) is reviewed in terms of the above reconstruction. I argue that Wronski's philosophical approach poses an alternative to the views of his contemporary mainstream mathematicians, which brings up the contingency of their choices, and bridges the foundational concerns of early modernity with those of the twentieth-century foundations crisis. I also argue that Wronski's views may be useful to contemporary philosophy of mathematical practice, if they are read against their metaphysical grain.

An experimental study on advancement of damping performance of foundations in soft ground. Pt.1: Forced vibration tests of a foundation block constructed on improved soil medium

International Nuclear Information System (INIS)

Ishimaru, S.; Shimomura, Y.; Kawamura, M.; Ikeda, Y.; Hata, I.; Ishigaki, H.

2005-01-01

Purpose of this study is to enhance attenuation performance of structures that will be constructed in the soft ground area. We conducted material tests to obtain basic properties of the soil cement column. The forced vibration tests then were carried out to acquire dynamic feature of the reinforced concrete block constructed on improved soil mediums. Additional forced vibration tests for various conditions of trenches dug along the block were conducted to obtain fundamental features of damping effect of the side surfaces of the test block. According to results of the material testing, densities of the soil cement columns were 1.45-1.52 g/cm 3 and the unconfined compressive strengths were 2.4-4.2 times as large as the specified design strength (1 MPa). In comparison of resonance curves by experiments and simulation analysis, simulation analysis results estimated by the hybrid approach were in good agreement with experiment ones for both the X and Y-directions. From the results of the forced vibration test focusing on various condition of the trenches dug along the test block, it was indicated that response of tamping by the rammer decreased compared with that of treading. (authors)

Evolution of power plant foundations in Nova Scotia

Energy Technology Data Exchange (ETDEWEB)

Chen, C.T.; Larade, M.; Myette, R.; MacIvor, T. [Nova Scotia Power Inc., Halifax, NS (Canada)

2009-07-01

Many thermal steam plants in Nova Scotia, including the first 3 units Dartmouth's Tufts Cove Generating Station, were constructed on bedrock and near the sea for easy access to cooling water. Major equipment foundations such as turbine/condenser foundations, boiler feed pump foundations and fan foundations are concrete block foundations that are designed to withstand the heavy equipment and environmental loads imposed throughout the service-life of the plant. This paper discussed the rationale for choosing different types of foundations at the 5 power generating units at the Tufts Cove Generating Station. Due to the presence of boulders, pipe piles were installed in drilled holes in 1995 for the unit 2 precipitator foundation. In 2005, micro-piles were installed for unit 1 and 3 precipitators because they were relatively non-protrusive for the congested urban site that was full of buried structures and services. Similarly, for the unit 4 and 5 sound wall foundations, the high resistance capacities for both downward and uplift loads of the micro-piles embedded into the bedrock proved to be very valuable. These tall wall structures are subject to very high wind loads and were constructed at a geotechnically challenged site. Good geotechnical investigation and consultation was shown to be the basis for good design and construction of foundation works. It was concluded that the lessons learned at Tufts Cove can be applied to other similar foundation designs. 7 refs., 10 figs.

Industrial Foundations as Long-Term Owners

DEFF Research Database (Denmark)

Thomsen, Steen; Poulsen, Thomas; Børsting, Christa Winther

Short-termism has become a serious concern for corporate governance, and this has inspired a search for institutional arrangements to promote long-term decision-making. In this paper, we call attention to long-term ownership by industrial foundations, which is common in Northern Europe but little...... known in the rest of the world. We use a unique Danish data set to document that industrial foundations are long-term owners that practice long-term governance. We show that foundation ownership is highly stable compared to other ownership structures. Foundation-owned companies replace managers less...... frequently. They have conservative capital structures with low financial leverage. They score higher on an index of long-termism in finance, investment, and employment. They survive longer. Overall, our paper supports the hypothesis that corporate time horizons are influenced by ownership structures...

Prefabricated EPS Elements used as Strip Foundation of a Single-family House with a Double Brick Wall

OpenAIRE

Rasmussen, Torben Valdbjørn

2008-01-01

A new prefabricated lightweight element was designed for a strip foundation that was demonstrated on site as the base of a single-family house with a double brick wall. The element was placed on a stable surface underneath the top soil layer, just 0.25 m underneath the finished ground surface. The prefabricated element was designed to fulfil the requirements of low energy consumption required by the new Danish Building Regulations. The base of the house was cast in one working operation and c...

Study of parameters important to soil-structure interaction in seismic analyses of nuclear power plants

International Nuclear Information System (INIS)

Nelson, T.A.

1983-12-01

The development of state-of-the-art techniques for analyzing the effects of soil-structure interaction (SSI) on structures during earthquakes is outlined. Emphasis is placed on methods to account for energy dissipation as a result of both wave propagation away from the structure's foundation and hysteretic soil response. Solution techniques are grouped into two major types: substructure methods, which break the problem into a series of steps; and direct methods, which analyze the soil-structure model in one step. In addition to theoretical and historical development of SSI methodology, case studies are presented illustrating the application of these solution techniques. 94 references

Foundations of Risk Analysis

CERN Document Server

Aven, Terje

2012-01-01

Foundations of Risk Analysis presents the issues core to risk analysis - understanding what risk means, expressing risk, building risk models, addressing uncertainty, and applying probability models to real problems. The author provides the readers with the knowledge and basic thinking they require to successfully manage risk and uncertainty to support decision making. This updated edition reflects recent developments on risk and uncertainty concepts, representations and treatment. New material in Foundations of Risk Analysis includes:An up to date presentation of how to understand, define and

Foundations of stochastic analysis

CERN Document Server

Rao, M M; Lukacs, E

1981-01-01

Foundations of Stochastic Analysis deals with the foundations of the theory of Kolmogorov and Bochner and its impact on the growth of stochastic analysis. Topics covered range from conditional expectations and probabilities to projective and direct limits, as well as martingales and likelihood ratios. Abstract martingales and their applications are also discussed. Comprised of five chapters, this volume begins with an overview of the basic Kolmogorov-Bochner theorem, followed by a discussion on conditional expectations and probabilities containing several characterizations of operators and mea

Foundations of predictive analytics

CERN Document Server

Wu, James

2012-01-01

Drawing on the authors' two decades of experience in applied modeling and data mining, Foundations of Predictive Analytics presents the fundamental background required for analyzing data and building models for many practical applications, such as consumer behavior modeling, risk and marketing analytics, and other areas. It also discusses a variety of practical topics that are frequently missing from similar texts. The book begins with the statistical and linear algebra/matrix foundation of modeling methods, from distributions to cumulant and copula functions to Cornish--Fisher expansion and o

The curator/patron: Foundations and contemporary art

Directory of Open Access Journals (Sweden)

Rebecca Coates

2008-12-01

Full Text Available This article addresses the role of private foundations in commissioning site-specific ephemeral art works: contemporary art projects of a temporary nature that are realised outside of public institutions. Though small in number, I argue that the private individuals creating and managing private foundations of this nature demonstrate a new form of patronage, creating in the process a new role of ‘curator/patron’. Equally, this process of realisation reflects the changing needs of contemporary art practice. Work of this scale and ambition would increasingly not be possible without the vision, perseverance and funding of these kinds of foundation. In Australia, this trend is demonstrated by two foundations: Kaldor Art Projects, and their commissioning of works by artists such as Christo and Jeanne-Claude, Gilbert & George and Jeff Koons; and the more recently formed Sherman Contemporary Art Foundation, whose first project was with Chinese artist Ai Weiwei. In this article, these examples are placed within the broader international context of foundation models such as Artangel, UK, Fondazione Nicola Trussardi, Milan, and The Public Art Fund, New York.

Characterization of bridge foundations workshop report.

Science.gov (United States)

2013-11-01

"In 2013, the Federal Highway Administration proposed a new research program for the characterization of bridge foundations. To narrow the focus and develop a research roadmap for the program, a workshop on Characterization of Bridge Foundations...

General cracked-hinge model for simulation of low-cycle damage in cemented beams on soil

DEFF Research Database (Denmark)

Skar, Asmus; Poulsen, Peter Noe; Olesen, John Forbes

2017-01-01

The need for mechanistic constitutive models to evaluate the complex interaction between concrete crack propagation, geometry and soil foundation in concrete- and composite pavement systems has been recognized. Several models developed are either too complex or designed to solve relatively simple...