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Full-Text Articles in Geotechnical Engineering
The Liquefaction Of Sand Lenses Due To Cyclic Loading, J. D. Holchin, L. E. Vallejo
The Liquefaction Of Sand Lenses Due To Cyclic Loading, J. D. Holchin, L. E. Vallejo
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Many studies have been conducted on the effects of cyclic loading on homogeneous saturated deposits of sand, and to a lesser extent on silt and clay. In contrast, very little research has been performed on the effects of cyclic loading on saturated sand lenses located within clay masses. Sand lenses and thin discontinuous layers of loose sand are frequently encountered in saturated clay or silt deposits located in areas of the United States prone to earthquakes. Sand lenses are also frequently associated with hydraulic fill structures, which are known to perform poorly during earthquake loading. The liquefaction and failure of …
Predicting Seismic Liquefaction Using Neural Networks, A. T. C. Goh
Predicting Seismic Liquefaction Using Neural Networks, A. T. C. Goh
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Neural networks have emerged as a powerful computational technique for modeling nonlinear multivariate relationships. The neural network is a product of artificial intelligence research. This paper examines the feasibility of using neural networks for assessing liquefaction potential, from actual field records. The paper starts with a brief overview of the basic architecture and concepts of neural networks. The application of the neural network methodology to evaluate seismic liquefaction potential is then presented.
Generalized Plasticity And Cyclic Pressuremeter Test Modelling, A. Saïtta, J. Canou, L. Dormieux
Generalized Plasticity And Cyclic Pressuremeter Test Modelling, A. Saïtta, J. Canou, L. Dormieux
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A constitutive model based on generalized elastoplasticity (Zienkiewicz et al., 1985) is used for the modelling of monotonic and cyclic pressuremeter tests in a clay. The permeability of the material is taken into account for the modelling of the excess pore water pressure generation during the test (combination of pore pressure build up and dissipation). It is shown how this type of model can simply represent the main features observed during a cyclic pressuremeter test in a clay, particularly the accumulation of excess pore water pressure during the cycles of loading, and the importance of dissipation on the excess pore …
Area Of Compaction To Prevent Uplift By Liquefaction, Yukihisa Tanaka, Hideo Komine, Jun-Ichi Tohma, Keizo Ohtomo, Hitoshi Tochigi, Hidenori Abo, Satoyuki Fukuda
Area Of Compaction To Prevent Uplift By Liquefaction, Yukihisa Tanaka, Hideo Komine, Jun-Ichi Tohma, Keizo Ohtomo, Hitoshi Tochigi, Hidenori Abo, Satoyuki Fukuda
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this study, shaking table tests, upper seepage flow tests and numerical analyses were conducted to determine the condition of improvement by the compaction method, including the extent of area and the density, to prevent uplift of underground pipes by liquefaction. Based on the results of these investigations, a procedure to determine the improvement conditions was proposed.
Numerical Simulations Of Soil Liquefaction Using Stochastic Input Parameters, R. Popescu, J. H. Prevost, E. H. Vanmarcke
Numerical Simulations Of Soil Liquefaction Using Stochastic Input Parameters, R. Popescu, J. H. Prevost, E. H. Vanmarcke
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The influence of spatial variability of soil properties on the results of numerical simulations of dynamically induced pore water pressure is addressed. Random media of NSPT values are generated based on in situ test results. The soil geomechanical properties are evaluated at each location, function of the NSPT values, and finite element simulations of the behavior of a horizontally layered soil subjected to seismic loading are performed. The influence of : (1) assumed distribution of the underlying random variable, (2) scale of fluctuation, and (3) finite element mesh size are discussed in terms of predicted liquefaction index and …
Effective Stress Liquefaction Analysis At The Wildlife Site, P. M. Byrne, J. Mcintyre
Effective Stress Liquefaction Analysis At The Wildlife Site, P. M. Byrne, J. Mcintyre
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An incremental stress-strain model for granular soils based on fundamental soil mechanics principles is presented. The model captures the drained skeleton behavior observed in laboratory tests under cyclic loading. The undrained behavior is captured using the same skeleton stress-strain relation together with the volumetric constraint imposed by the pore water fluid. The model predicts cyclic simple shear response in close agreement with observed cyclic test data in terms of pore water pressure rise, cycles to trigger liquefaction, as well as the characteristic post-liquefaction response. Finally, the model is incorporated in a dynamic analyses procedure and applied to the field case …
Settlement In Sands Due To Cyclic Loading, A. Erken, A. M. Ansal, E. Alhas
Settlement In Sands Due To Cyclic Loading, A. Erken, A. M. Ansal, E. Alhas
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Stress controlled undrained cyclic triaxial tests have been conducted on undisturbed sandy and silty soil samples obtained by special sampler in order to minimize the effect of disturbance. The influence of fines content on liquefaction - induced volumetric strains have been studied. The results indicate that cyclic mobility of sands is affected by non – plastic fines content. As fines content increase, cyclic shear strength decreases. Volumetric strain is influenced by fines content as well as shear strain and cyclic stress. At large shear strains amplitudes, an increase in percentage of fines causes more volumetric strains. Volumetric strains of silt …
Determination Of Liquefaction Potential Using Dielectric Concept, A. Kaya, H. Y. Fang
Determination Of Liquefaction Potential Using Dielectric Concept, A. Kaya, H. Y. Fang
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this paper existing insitu test methods to determine possible liquefaction potential of a site are discussed briefly with their advantages and limitations. Then, resistivity method is presented and showed how both resistivity and dielectric constant can be coped to determine insitu properties of soils such as cementation factor and porosity without disturbing the soil structure by means of Time Domain Reflectometry (TDR). A procedure is also presented to obtain both resistivity and dielectric constant of granular soils in the field. It is concluded that the proposed method and procedure is superior to the existing methods.
Lateral Stress Ratio On Retaining Structures After Earthquake Loading, Constantine A. Stamatopoulos
Lateral Stress Ratio On Retaining Structures After Earthquake Loading, Constantine A. Stamatopoulos
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Equations are derived by analysis g1vmg the earthquake-induced change in the permanent horizontal stress acting on frictionless vertical walls retaining dry sand. These equations exhibit a limit in the coefficient of lateral pressure that depends only on the slope of the critical state line and the Poisson's Ratio of the backfill. The horizontal stress after dynamic shaking increases or decreases towards this limit. Predictions agree qualitatively with results of laboratory tests.
Soil-Diaphragm Wall Interaction In Floating Dam, H. Watanabe, K. Kanazawa
Soil-Diaphragm Wall Interaction In Floating Dam, H. Watanabe, K. Kanazawa
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Stability of embankment dam with diaphragm cutoff wall constructed on riverbed sediment depends on structural behavior of local part around top of the wall. A numerical method to evaluate static and dynamic behavior of the part including earth pressure concentration is proposed and the validity is confirmed by comparison of numerical results of full construction process with observed ones in a prototype dam. Besides, in-situ vibration tests are performed on testing diaphragm wall constructed in dam site for banking test to reveal dynamic behavior of the wall. Furthermore, earthquake response analysis of whole structure is carried out to clarify behavior …
Shaking Table Tests And Numerical Simulation Of Seismic Response Of The Seawall, Y. Nishimura, S. Fukui, M. Sato, H. Kurose, M. Fujitani
Shaking Table Tests And Numerical Simulation Of Seismic Response Of The Seawall, Y. Nishimura, S. Fukui, M. Sato, H. Kurose, M. Fujitani
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Shaking table tests of a caisson seawall model were conducted to investigate sliding phenomena of the seawall. The response characteristics of the caisson placed on the mound which was fixed to the shaking table were investigated in the six series of experiments with varying the situation of the model; with or without backfill, wave breaking works and water. These test results were utilized to validate a two-dimensional FEM analysis method with joint elements. The numerical model with the finer mesh division and joint elements showed fairly close results with the series of test results, resulting the better representation of the …
Earthquake Induced Displacement Of Gravity Retaining Walls, X. Zeng
Earthquake Induced Displacement Of Gravity Retaining Walls, X. Zeng
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Centrifuge tests were conducted to study the displacement of gravity retaining walls during earthquakes. Theoretical analysis based on Newmark's sliding block method was used to analyze the data. For a gravity wall with dry backfill, sliding block method generates reasonable results. However, the method is difficult to apply for a retaining wall with saturated backfill. Comprehensive numerical methods need to be used. A method of calculating the tilting of gravity walls is introduced.
Dynamic Active Earth Pressure Against Retaining Walls, S. A. Anvar, A. Ghahramani
Dynamic Active Earth Pressure Against Retaining Walls, S. A. Anvar, A. Ghahramani
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Equations of equilibrium expressed along the stress characteristics are transformed onto the Zero Extension Line (ZEL) directions. The new dynamic equilibrium equations are then applied to simple ZEL field (composed of Rankine, Goursat, and Coulomb zones) behind retaining walls. Integration of differential equilibrium equations along the assumed field boundary, thus provide the final equations for the active static (Kast) and dynamic (Kady) earth pressure coefficients, which are functions of friction and dilation angles of the soil and friction angle of the wall surface. Numerical evaluation of Kast, and Kady indicates that these coefficients …
On Seismic Design Displacements Of Rigid Retaining Walls, Shamsher Prakash, Yingwei Wu, Eyjolfur Ami Rafnsson
On Seismic Design Displacements Of Rigid Retaining Walls, Shamsher Prakash, Yingwei Wu, Eyjolfur Ami Rafnsson
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Correlation of the dynamic displacement and significant factors are presented. Three computer programs (Rafnsson, 1991) have been modified to develop design charts. The wall dimension computed by static condition and related displacement under dynamic loading can be estimated from the computer programs. Twenty-one combinations of base soil and back fill, 5 different ground motions and 7 different heights of wall are used in the analyses to develop design charts. These will help the designer to predict the dynamic behavior of retaining walls and to optimize the design work. Furthermore, equations have been fitted to predict the displacement without using the …
Discussions And Replies — Session Iv, Multiple Authors
Discussions And Replies — Session Iv, Multiple Authors
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
No abstract provided.
Lumped-Parameter Model And Nonlinear Dssi Analysis, Maotian Luan, Gao Lin, W. F. Chen
Lumped-Parameter Model And Nonlinear Dssi Analysis, Maotian Luan, Gao Lin, W. F. Chen
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A 2-.degrees-of-freedom discrete model with 8 constant lumped parameters is developed to equivalently simulate frequency-dependent dynamic impedances of the elastic halfspace. The equations of motion for the nonlinear dynamic soil-structure interaction (DSSI) analysis are established in the time domain and then nonlinear seismic responses of the coupling system are predicted by the proposed iterative procedure. Based on numerical results for three typical shear-type structures, effects of the shear stiffness of underlying soils and different ground motions on dynamic responses are examined.
Effect Of Soil Dilatancy On Vibration And Earth Pressure, Y. Ohshima, H. Watanabe
Effect Of Soil Dilatancy On Vibration And Earth Pressure, Y. Ohshima, H. Watanabe
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A model ground of air dried sand compacted in a shear testing apparatus and two composite models each of which have the model pit of different rigidity buried in a same model ground as above one are excited horizontally with sinusoidal motions on a shaking table. From measured accelerations and dynamic earth pressure it is found that the vertical vibration is produced in the ground due to the dilatancy or volume change of soil and yet it produces the dynamic earth pressure acting horizontally on all outside walls of the model pit. In order to simulate the results of tests …
Dynamics Of Rigid Foundations On Fluid-Saturated Soil, A. R. Khoee, A. M. Kaynia
Dynamics Of Rigid Foundations On Fluid-Saturated Soil, A. R. Khoee, A. M. Kaynia
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper presents a three-dimensional boundary element formulation for the steady-state dynamic analysis of fluid saturated porous media. The coupled differential equations are derived from the field equations by the application of the Fourier Transform. The boundary integral formulation is obtained by the weighted residual method and the associated fundamental solutions are obtained by the method developed by Kupradze. The boundary element model is used to obtain compliance functions of square rigid foundations bonded to the surface of a water-saturated half-space. The effect of the soil permeability on the variation of the compliance functions is also examined.
Improved Soil-Spring Method For Soil-Structure Interaction — Vertical Excitation, A. H. Hadjian, H. T. Tang
Improved Soil-Spring Method For Soil-Structure Interaction — Vertical Excitation, A. H. Hadjian, H. T. Tang
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An improved Soil-Spring Method for vertical response analysis is proposed. The Soil-Spring Method belongs to the sub structuring methods of analyses for seismic soil-structure interaction. As originally developed the method has certain significant limitations. The proposed improvement is essentially iterative where, successively, layering, embedment, soil damping and frequency-dependent effects are introduced and adjusted until acceptable convergence is achieved. Additionally, input motion for embedded structures is specified using a simple procedure. The methodology is applied to the Lotung 1/4-scale containment model for three recorded earthquakes. The comparisons of the response results with the recorded data and with results obtained using state-of-the-art …
Cyclic Mobility Effects On Soil-Pile Interaction In Dense Sand, F. Pelli, E. J. Parker, L. Conte, M. Bosoni
Cyclic Mobility Effects On Soil-Pile Interaction In Dense Sand, F. Pelli, E. J. Parker, L. Conte, M. Bosoni
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A methodology to evaluate the effects of earthquake-induced cyclic mobility in dense sand on the soil-pile interaction parameters is presented. The soil behavior under cyclic loading is defined based on the interpretation of consolidated-undrained cyclic triaxial tests on samples reconstituted to the in situ relative density and shear wave velocity. The stress distribution around the pile is determined analytically, and the softened zone is modelled by an annulus of softer soil. The application of this methodology for the design of three submerged-floating tunnels in the Messina straits, Italy, indicated that even in dense sand the foundation stiffness reduction can be …
Foundation Soil Influence On The Seismic Response Of Piers, P. P. Diotallevi, R. Poluzzi
Foundation Soil Influence On The Seismic Response Of Piers, P. P. Diotallevi, R. Poluzzi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Significant experimental dynamic tests by vibrodyne were conducted on single piers of a motorway near Livomo (Italy). Tests were conducted on structures similar to each other but founded on two different type of soils (under consolidated silts below the water table and over consolidated clays) and very different dynamic responses were found in terms of damping and natural frequencies. This effect was particularly evident for single piles proving the importance of soil characteristics upon the dynamic response of the structure. It is refere also a numerical investigation about the behavior of identical structures founded on different soils and subjected to …
Settlement Of Shallow Foundation On Sand Due To Cyclic Loading, B. M. Das, S. C. Yen, G. Singh
Settlement Of Shallow Foundation On Sand Due To Cyclic Loading, B. M. Das, S. C. Yen, G. Singh
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Laboratory model test results for the permanent settlement of a surface square foundation supported by a sand layer and subjected to a sustained static load superimposed by a cyclic load has been presented. Based on the model test results, the nature of variation of the permanent settlement of the foundation with the intensity of the static loading and the amplitude of the cyclic load intensity are presented.
Application Of Weak Earthquake Records In Soil-Structure Interaction Analysis, E. Juhásová
Application Of Weak Earthquake Records In Soil-Structure Interaction Analysis, E. Juhásová
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The problem concerns cases when the structure is situated in the geological conditions with different soil layers including soft ones. The wave motion in the subsoil is described for linear and non-linear soil media, damping is included through complex modulus of elasticity. Variation of damping, obtained from laboratory experiments, answers to frequency and time influences. The properties of weak earthquakes are discussed as they are used like input data before soil transfer. The response of layered subsoil describes extremes of seismic vibration at different depth. It has been recognized that site effects can significantly affect the nature of seismic input …
Recommendations Of A Workshop For A Soil-Structure Interaction Experiment, M. Celebi, J. E. Luco
Recommendations Of A Workshop For A Soil-Structure Interaction Experiment, M. Celebi, J. E. Luco
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A workshop held in 1992 (Celebi et al., 1992) brought together a panel of experts (a) to reach a consensus on the benefits and feasibility of instrumenting a building in a seismically active region of the United States to study specifically the effect of soil-structure interaction (SSI), and (b) to define the parameters of a SSI experiment. The recommendations of the workshop and the current status of the SSI experiment are described herein.
Prediction Of Non-Linear Pile Foundation Response To Vertical Vibration, Toyoaki Nogami, Hsiao-Lian Chen
Prediction Of Non-Linear Pile Foundation Response To Vertical Vibration, Toyoaki Nogami, Hsiao-Lian Chen
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A rational and yet convenient approach is presented to account for the dynamic soil-pile interaction in the vertical vibration analysis of a nonlinear pile foundation. Once elastic soil properties and static complex unit load transfer curves are provided, the approach is capable of reproducing the dynamic and nonlinear conditions mutually coupled. The concept of the approach is verified by numerical analyses. The proposed approach is demonstrated for the prediction of vibration response of a selected pile foundation in the field. Both static load tests and vibration tests were conducted previously on this pile foundation. Inputs for the analysis are obtained …
Dynamic Interaction Of An Uplifted Beam With The Supporting Soil, Medhat A. Haroun, Ali A. El-Zeiny
Dynamic Interaction Of An Uplifted Beam With The Supporting Soil, Medhat A. Haroun, Ali A. El-Zeiny
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
During seismic events, the overturning moment exerted by the hydrodynamic pressure of a liquid contained in an unanchored, thin-walled liquid storage tank tends to lift the tank base plate off its foundation. The nonlinear uplift and contact mechanism between the base plate and the underlying foundation is investigated in the present study. Nonlinearities due to base plate contact with foundation, large deflection and plastic hinge formation are examined.
Evaluation Of Seismic Response Of Pile-Supported Structures With 3-D Nonlinear Approach, Y. X. Cai, P. L. Gould, C. S. Desai
Evaluation Of Seismic Response Of Pile-Supported Structures With 3-D Nonlinear Approach, Y. X. Cai, P. L. Gould, C. S. Desai
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The seismic response of pile-supported structures is evaluated using a three-dimensional finite element subsystem methodology with an advanced plasticity based constitutive model for soils. The motion of the pile foundation is amplified due to the soil-pile-structure interaction. The dynamic internal forces of the structures obtained by the 3-D nonlinear approach deviate significantly from those obtained by the rigid ground motion model. The structures are generally subjected to three-dimensional forces and couples, despite the type of bedrock seismic excitation and the configuration of structures. Some components of the dynamic internal forces may be overlooked if the simplified symmetric models are used …
Nonlinear Dynamic Impedance Of Pile Group Foundation, K. Miura, K. Masuda, T. Maeda, T. Kobori
Nonlinear Dynamic Impedance Of Pile Group Foundation, K. Miura, K. Masuda, T. Maeda, T. Kobori
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The dynamic impedance of a pile group must be determined to perform a dynamic response analysis of the structure it supports. This problem has attracted continued research interest, but most research to date has been on linear soil media. When the excitation level becomes large during an earthquake or a machine type excitation, stress concentration occurs in the soil surrounding the pile, causing the soil to behave nonlinearly. Calculation of pile group impedance necessitates analysis of pile-soil-pile interaction. Any soil nonlinearity around the piles must be taken into account in this analysis. However, the effect of nonlinearity on dynamic impedance …
Seismic Response On Full-Size Pile Group, Y. C. Han, G. C. W. Sabin
Seismic Response On Full-Size Pile Group, Y. C. Han, G. C. W. Sabin
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Seismic response of pile group is investigated in both theory and experiment. The dynamic experiments were conducted on a full-size pile group in linear vibration and nonlinear vibration respectively, and the impedances of group were determined using the boundary zone model with non-reflective interface. The theoretical and experimental results indicate that the response of pile group may be increased substantially with the nonlinearity of soil-pile system in a seismic event, and there is a pronounced increase in the horizontal seismic response of group with the pile-soil-pile interaction.
Rescue Testing Of Full-Scale In-Situ Structures, P. R. Gefken, J. W. Simons
Rescue Testing Of Full-Scale In-Situ Structures, P. R. Gefken, J. W. Simons
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
At SRI International a state-of-the-art technique for testing large-scale structures to dynamic motion resembling that from a large magnitude earthquake has been developed. The technique, referred to as repeatable earth shaking by controlled underground expansion (RESCUE), may allow actual full-scale structures to be tested in-situ. In this paper we present the results of a finite element simulation of a full-scale highway overpass loaded from ground motion produced by the RESCUE technique. Results indicated that the RESCUE technique could generate significantly enough ground motion to excite failure damage modes.