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Dynamic Active Earth Pressure Against Retaining Walls, S. A. Anvar, A. Ghahramani Apr 1995

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 …

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Dynamics Of Rigid Foundations On Fluid-Saturated Soil, A. R. Khoee, A. M. Kaynia Apr 1995

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.

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Efficient Evaluation Of Dynamic Impedance, Gao Lin, Huai-Hai Chen Apr 1995

Efficient Evaluation Of Dynamic Impedance, Gao Lin, Huai-Hai Chen

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

An efficient algorithm for the calculation of dynamic impedance of viscoelastic multilayered media is presented. The wavenumber integral over infinite limits are split into two subintervals, the first one is dominated by the plane waves while the second is dominated by the surface Rayleigh waves. Though the integrand of the first one is characterized by dense oscillations and sharp peaks, its integration covers very narrow range and can be evaluated sufficiently accurately with dense sampling points. The integrand of second one varies very smoothly and can be determined analytically, the integration is easy to perform. The advantages of the present …

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Efficiency Of An Energy-Dissipating Barrier, M. P. Luong Apr 1995

Efficiency Of An Energy-Dissipating Barrier, M. P. Luong

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The proposed paper describes some experimental procedures, used in (a) laboratory to recognize the energy-dissipating ability of soil and (b) in centrifuge to generate in-flight stress waves propagating through a centrifugal soil mass in order to investigate the efficiency of a stress wave mitigation barrier. The screening principle of this new type of energy-dissipating barrier has been suggested by the dissipative behavior of sandy soils, evidenced by infrared vibrothermography.

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Generalized Plasticity And Cyclic Pressuremeter Test Modelling, A. Saïtta, J. Canou, L. Dormieux Apr 1995

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 …

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Prediction Of Settlements Of Soft Clay Caused By Earthquakes, Zhou Jian, K. Yasuhara Apr 1995

Prediction Of Settlements Of Soft Clay Caused By Earthquakes, Zhou Jian, K. Yasuhara

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper develops an analytical method for the calculation of the earthquake-induced settlement of foundation by using Biot's type consolidation equation. In order to investigate the effectiveness of the proposed method, a comparison of the numerical result with the observed earthquake-induced settlement on the site at Sendai in Japan caused by the miyagioki earthquake in 1987 will be presented.

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Improved Soil-Spring Method For Soil-Structure Interaction — Vertical Excitation, A. H. Hadjian, H. T. Tang Apr 1995

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 …

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Application Of Weak Earthquake Records In Soil-Structure Interaction Analysis, E. Juhásová Apr 1995

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 …

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Seismic Response Of 20-Valleys: Local Site Effects, K. E. Loukakis, J. Bielak Apr 1995

Seismic Response Of 20-Valleys: Local Site Effects, K. E. Loukakis, J. Bielak

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Layering and geometry effects on ground response of two-dimensional sedimentary valleys under oblique seismic excitation are investigated. The seismic wave has the shape of a half cycle incoming pulse with SV-wave characteristics. Vertical and oblique incoming signals of varying duration are used. The analysis is performed using finite element techniques, an equivalent effective force method to prescribe the free field motion within the domain of computation, and an artificial boundary to absorb the scattered motion. Simple examples are presented confirming the validity of this methodology. It is shown that surface waves generated at the valley edges propagate through the basin …

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Dynamic Modeling Of Layered Systems To Moving Surface Loads: Applications, Raj Siddharthan, Gary M. Norris, Mahmoud El-Gamal Apr 1995

Dynamic Modeling Of Layered Systems To Moving Surface Loads: Applications, Raj Siddharthan, Gary M. Norris, Mahmoud El-Gamal

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Two important application of a recently developed moving load model are described. The model uses an efficient semi analytical "finite layer" formulation of the porous medium. One application is a response of a layered sandy nonlinear porous medium, while the other is a viscoelastic pavement layer system. The study reveals that the properties of the layers and porefluid and the moving velocity of the load are important factors that affect the response of the layered system.

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Theoretical Investigations On The Nakamura's Technique, C. Lachet, P. Y. Bard Apr 1995

Theoretical Investigations On The Nakamura's Technique, C. Lachet, P. Y. Bard

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

We use synthetic calculations to investigate the spectral ratio between horizontal and vertical components (H/V ratio), derived from noise simulation, in order to appreciate the reliability of the so-called Nakamura's method for site effects applications. This ratio shows a peak whose position generally coincides with the fundamental resonance frequency. We show that this position is independent of the source function, whereas it is characteristic of the geological structure. We also compare these results with those obtained for vertical S waves and Rayleigh waves, in order to better understand the significance of this HIV peak. Finally, we show that the amplitude …

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Discussions And Replies — Session Xii, Multiple Authors Apr 1995

Discussions And Replies — Session Xii, Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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Lumped-Parameter Model And Nonlinear Dssi Analysis, Maotian Luan, Gao Lin, W. F. Chen Apr 1995

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.

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Nonlinear Dynamic Impedance Of Pile Group Foundation, K. Miura, K. Masuda, T. Maeda, T. Kobori Apr 1995

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 …

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Scattering Of Sh-Waves By Arbitrary Surface Topography, M. E. Manoogian, V. W. Lee Apr 1995

Scattering Of Sh-Waves By Arbitrary Surface Topography, M. E. Manoogian, V. W. Lee

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The weighted residual method was applied to the problem of scattering and diffraction of plane SH-waves by a shallow alluvial valley of arbitrary shape on the surface of a two-dimensional half-space. The formulation was also applied to the case of a shallow canyon. In order to demonstrate the versatility of the method, it was applied to shallow circular, shallow elliptical, and shallow rectangular canyons and alluvial valleys. Results obtained for the cases of a semi-cylindrical and a shallow semi-elliptical valleys and canyons match those obtained using closed form solutions. It was shown that significant ground motion amplifications, with respect to …

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Stress Wave Propagation In Unsaturated Sands, G. E. Veyera, C. A. Ross Apr 1995

Stress Wave Propagation In Unsaturated Sands, G. E. Veyera, C. A. Ross

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Wave transmission tests were conducted on specimens of Eglin and Ottawa 20-30 sands at saturations varying from dry to near 100% using a Split-Hopkinson Pressure Bar. Specimens were compacted to a constant dry density in a thick-walled stainless steel container using a standard Proctor hammer. Compacted specimens were loaded in undrained, dynamic uniaxial confined compression at strain rates of approximately 13/s to 19/s. Tests were conducted on dry specimens; specimens compacted moist and tested moist; specimens compacted moist and dried before testing. For a constant input stress, transmitted stress and compressional wave propagation velocity were seen to vary with saturation. …

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Assessment Of Ground Vibration From Passing Train, Ján Benčat Apr 1995

Assessment Of Ground Vibration From Passing Train, Ján Benčat

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Increasing demands on speed increase, higher axle on transportation over dimensional and heavy loads cause simultaneous increase of unfavorable traffic effect on the structures of railways and on the train-induced ground vibration, respectively. This paper examines the residual problems of ground-borne vibration, the vehicle and track features which might be responsible for generation, how it is propagated, and how it might affect. A few of experimental results which have been obtained during studies made on Slovak Railways (ZSR) are presented in the paper, too.

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Response Of Embedded Circular Flexible Foundations, N. Gucunski Apr 1995

Response Of Embedded Circular Flexible Foundations, N. Gucunski

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The stiffness matrix approach to the solution of vertical vibrations of a circular flexible foundation embedded in a viscoelastic layered half-space have been described. Results of a parametric study, represented by displacement and soil reaction distributions and impedances, indicate a significantly different responses of flexible and rigid foundations. Important parameters are identified and include: the stiffness ratio, depth of embedment, soil stratification and loading distribution. Influence of each of the parameters is discussed.

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Table Of Contents, Multiple Authors Apr 1995

Table Of Contents, Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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Three-Dimensional Cyclic Behaviour Of Interfaces, E. Evgin, K. Fakharian Apr 1995

Three-Dimensional Cyclic Behaviour Of Interfaces, E. Evgin, K. Fakharian

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

A new apparatus is used to study the behavior of an interface between dry sand and a rough surface under three dimensional cyclic loading conditions. A simple shear type of soil container is utilized in the experiments to investigate the coupling effects of two orthogonal shear stresses acting on the interface. The significance of the results are discussed with reference to the behavior of axially-laterally loaded piles.

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A New Method For Determining The Anisotropic Parameters Of Materials Under True Triaxial Cyclic Loading, Q. J. Yang, B. Shackel Apr 1995

A New Method For Determining The Anisotropic Parameters Of Materials Under True Triaxial Cyclic Loading, Q. J. Yang, B. Shackel

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

In this paper a new approach to solving the basic equations of elastic cross-anisotropic stress and strain relationships is presented. The uniqueness of the equations is demonstrated and the conditions for their use are easily controlled in the true triaxial test equipment available in the laboratory. By this approximate solution the four anisotropic parameters of cross-anisotropic materials can be obtained. In addition, so-called fuzzy logic weighting factors are introduced to assess the differences among the observed principal deformations of samples tested. A computer program ANISOLV has been written to calculate the formulated parameters. Some typical examples are given to demonstrate …

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Verification Of An Elasto-Piastic Earthquake Analysis Procedure, A. Anandarajah Apr 1995

Verification Of An Elasto-Piastic Earthquake Analysis Procedure, A. Anandarajah

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

An effective stress based, finite element procedure of modeling earthquake soil and soil-structure interaction problems is described. Elasto-plastic constitutive models are used to describe the stress-strain behavior of soils. A fully-coupled finite element formulation is employed, which allows the pore pressure build-up and dissipation to be modelled simultaneously. Undrained behavior is modelled as a special case of this general formulation. In a previous study, the procedure was used to perform a “before the event” prediction of the liquefaction behavior of a 10-meter thick saturated sand deposit subjected to an earthquake loading. In the present paper, the predictions are compared with …

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Behaviour Of Saturated Sand Models Under Principal Stress Axes Rotation In Shake Table Tests, Eiji Yanagisawa, Fardin Jafarzadeh Apr 1995

Behaviour Of Saturated Sand Models Under Principal Stress Axes Rotation In Shake Table Tests, Eiji Yanagisawa, Fardin Jafarzadeh

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

One dimensional shake table tests were performed on saturated loose or medium dense Toyoura sand models, in order to study the response of level grounds during earthquakes and the nature of generated excess pore water pressure. 12 virgin models which prepared under identical condition, were subjected to cyclic and three different irregular shear stress patterns. It is shown that there is correlation between excess pore pressure ratio and developed shear strain, independent from applied shear stress histories and density of the models. Also, the relations of accumulated shear work as well as normalized shear work, per unit volume, are considered …

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Numerical Simulations Of Soil Liquefaction Using Stochastic Input Parameters, R. Popescu, J. H. Prevost, E. H. Vanmarcke Apr 1995

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 …

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Past Proceedings: Third International Conference On Recent Advances In Geotechnical Earthquake Engineering And Soil Dynamics, St. Louis (1995), Multiple Authors Apr 1995

Past Proceedings: Third International Conference On Recent Advances In Geotechnical Earthquake Engineering And Soil Dynamics, St. Louis (1995), Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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Discussions And Replies — State-Of-The-Art, Multiple Authors Apr 1995

Discussions And Replies — State-Of-The-Art, Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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General Report— Session Vii: Soil Amplification During Earthquakes And Microzonation, Mehmet Celebi, G. R. Saragoni Apr 1995

General Report— Session Vii: Soil Amplification During Earthquakes And Microzonation, Mehmet Celebi, G. R. Saragoni

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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General Report —Session I: Static And Dynamic Engineering Soil Parameters And Constitutive Relations Of Soils, Peter M. Byrne, Li Yan Apr 1995

General Report —Session I: Static And Dynamic Engineering Soil Parameters And Constitutive Relations Of Soils, Peter M. Byrne, Li Yan

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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General Report —Session X: Wave Propagation In Soils, J. M. Roesset, G. Sanatana, I. S. Salinero Apr 1995

General Report —Session X: Wave Propagation In Soils, J. M. Roesset, G. Sanatana, I. S. Salinero

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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General Report —Session V: Soil Structure Interaction Under Dynamic Loading, A. H. Hadjian, T. Kobori, J. E. Luco, S. A. Savidis, Alex Sy Apr 1995

General Report —Session V: Soil Structure Interaction Under Dynamic Loading, A. H. Hadjian, T. Kobori, J. E. Luco, S. A. Savidis, Alex Sy

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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