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Nonlinear Seismic Analysis Of Building - Foundation Soil Systems, M. Sobaih, A. Gabr, A. H. Mahmoud, M. M. Bahloul

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

This paper deals with the problem of nonlinear seismic analysis of building - foundation soil systems. The building considered is modeled as a shear - type building supported on the surface of homogeneous isotropic elastic half-space. The governing nonlinear equations of motion for the structure - soil system are solved in the time domain using the step-by-step linear acceleration method of analysis with Wilson-e modification. Different nonlinear models to simulate the behaviour of reinforced concrete under cyclic loading are used. A parametric study has been performed on a single story shear-type building with different natural frequencies supported on the surface …

Pile Group Stiffness For Seismic Soil-Structure Interaction, Anshuli Arya, Anand S. Arya

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

This paper deals with stiffnesses of pile groups based on single pile stiffness as worked out by Novak and Sharnouby (1983) using dynamic analysis. The interaction factors between two neighboring piles are used as those derived by Poulos (1971) statically but assumed to hold under dynamic situation at low frequencies such as involved in earthquakes. Pile groups of 4 to 32 piles in single circular ring and up to 60 piles in multiple rings as used under raft foundations of circular chimneys and overhead water tanks are accordingly analysed. It is found that the stiffness of the group is much …

Seismic Response Of Floating Piles To Obliquely Incident Waves, Shahid Ahmad, S. M. Mamoon

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

The response of single piles under vertically and obliquely incident SH, SV, and P waves is obtained using a hybrid boundary element (BEM) formulation. The piles are represented by compressible beam-column elements and the soil as a hysteretic viscoelastic half-space. A recently developed Green function corresponding to the dynamic Mindlin problem is implemented in the numerical formulation. Exact analytical solutions for the differential equations for the piles under distributed harmonic excitations are used. Treating the half-space as a three-dimensional elastic continuum, the interaction problem is formulated by satisfying equilibrium and displacement compatibility along the pile-soil interface. Solutions adopted for the …

Study On Dynamic Characteristics Of A Pile Group Foundation, Takuji Kobori, Kenji Miura, Masaaki Nakazawa, Katsuichiro Hijikata, Yuji Miyamoto, Takafumi Moroi, Yoshinao Kobayashi

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

The earthquake response of a structure on group of piles is investigated. The test model, which is employed in this study, is a foundation on four piles. Three conditions are prepared for examination of the contact effects of the foundation bottom and the backfilling effects on dynamic characteristics of the foundation on the piles. Forced vibration tests are carried out for ascertaining the impedance functions as the inertial interaction, and earthquake observations for the earthquake input motion as the kinematic interaction. On the basis of the test and the observation results, the correlation analyses are executed for examining the applicability …

The Learning From The Large Scale Lotung Soil-Structure Interaction Experiments, A. H. Hadjian, D. Anderson, W. S. Tseng, N. C. Tsai, C. Y. Chang, Y. K. Tang, H. T. Tang, J. C. Stepp

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

Blind prediction analyses and subsequent correlation studies of a 1/4-scale reinforced concrete containment model constructed at Lotung, Taiwan subject to forced vibration tests and actual earthquakes are evaluated with the objective of validating soil-structure interaction (SSI) analysis methodologies commonly used in U.S. practice. The SSI methods used range from simple soil-spring representation to more complex finite-element methods and sub structuring techniques. Both forced vibration test (FVT) data and actual earthquake induced response data have been obtained for use in validating selected SSI analysis methodologies. Considering that for forced vibration tests only the stiffness and damping characteristics of the foundation are …

Site Amplification Effects In The Ubaye Valley (France): Measurements And Modeling, Denis Jongmans, Michel Campillo

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

Local soil conditions can yield to significant variations in ground motion generated by earthquakes. During the last two decades, these amplification effects have been observed by numerous authors for well-documented earthquakes. On the other hand, theoretical models and numerical techniques have been proposed to physically understand site effects. However, few comparisons have been made between observations and theoretical results for well-known 2D structures (sediment-filled valleys). The aim of this paper is to present a study of the response of a valley in the French Alps. The structure (Ubaye valley) was chosen for its moderate dimensions (500 meters wide and 65 …

Geological And Seismicity Evaluation Of Srinagarind Dam, S. Klaipongpan, V. Chakramanont, J. Pinrode, P. Chittrakarn

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

In April of 198 3, a sequence of earthquakes were recorded by the National Seismic Network where the epicenters were located in the upper reaches of the Srinagarind Reservoir. A detailed evaluation of these earthquakes has been initiated since that time. Network of micro seismic instruments have also been installed in the region in order to establish the capability of higher resolution for seismic parameters and allow the greater understanding of the mechanism of the activity. After seven years of monitoring and data collecting, analyses of the results have been performed. Results obtained from the evaluation of overall characteristic seismicity, …

Investigation Of Stress Waves Reflection Problems From A Free Surface By Dynamical Photoelasticity Method, I. Ch. Kostin

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

No abstract provided.

Leak Detection In Large Storage Tanks Using Seismic Boundary Waves, M. Kashi, K. Maser, A. Sotoodehnia

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

This paper describes a field evaluation of a technique for detecting leaks in large above ground storage tanks. The technique detects leaking tank products in the foundation material by sensing anomalies in seismic boundary waves transmitted across the tank bottom. The evaluation consisted of three steps: (1) investigation of surface (Rayleigh) wave anomalies due to surface soil saturation in linear arrays; (2) evaluation of boundary waves propagated across the bottom of typical tanks; and (3) a surface (Rayleigh) wave experiment using tomography to locate velocity changes due to surface soil saturation. The results of these tests have shown that boundary …

Soil Profiling By Spectral Analysis Of Surface Waves, T. Satoh, K. Yamagata, C. J. Poran, J. A. Rodriguez

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

Methods for in-situ surface measurement and spectral analysis of Rayleigh waves for subsurface soil investigation have been tried by several researchers in recent years. The two most common methods, steady-state Rayleigh-wave and spectral-analysis-of-surface-waves (SASW) have certain disadvantages and are not used for routine soil investigation. The paper presents a system which uses a controlled vibration source with amplitude modulation and variable frequency capabilities. The electromagnetic vibrator may be varied in size and weight according to the depth of the soil strata investigated. The Rayleigh wave phase velocity dispersion curves are used to compute apparent velocity distribution in depth. An approximate …

Three Dimensional Wave Propagation Due To Pile Driving, S. Savidis, A. Mitakidis

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

A very economical and efficient method to construct pile foundations or sheet walls is given by the driving of the pile itself in the case of prefabricated piles or of the steel-sheet pipe for concrete piles in situ and also by the driving of the sheet piles in the case of sheet walls. In spite of its efficiency this method underlies, because of environment protection reasons to certain restrictions that concern the influence of the produced shock waves during the driving procedure to neighboring buildings and constructions. For the theoretical calculation of this influence at first the free-field response of …

Use Of Rayleigh Modes In Interpretation Of Sasw Test, N. Gucunski, R. D. Woods

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

The Spectral-Analysis-of-Surface-Waves (SASW) method is a seismic method for measuring in situ elastic moduli of layered systems, like soils or pavements. The inversion process associated with SASW can be an ambiguous task in certain cases, because a field dispersion curve needs to be matched with an unknown path through a family of theoretically defined curves for an assumed profile. A study of the influence of soil stratification on participation of higher Rayleigh modes in surface wave propagation included the evaluation of theoretical dispersion curves, modal shapes and rates of energy transmission in the horizontal direction. Wave propagation due to oscillations …

Session 11: Discussions And Replies, Multiple Authors

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

No abstract provided.

Pile Driving Analysis: Two-Phase Finite Element Approach, P. Hölscher

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

The pile-driving process is analysed using the dynamic finite element program SATURN. The soil is modelled as a two-phase (skeleton and water) axi-symmetric continuum. The elasto-plastic behaviour of the skeleton is considered. Energy dissipation due to radiation, plastic deformation and water-skeleton friction is taken into account. The importance of permeability of the soil, its strength and its dilatancy are outlined. The soil resistance under the toe is strongly influenced by the low compressibility of the water. The results of the simulations show that the non-linear soil behaviour around the pile toe cannot be simulated satisfactorily using a single phase material. …

Torsional Dynamic Response Of Embedded Footings, Peiji Yu, E. B. Wylle, F. E. Richart Jr.

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

A computer program, originally prepared to evaluate stresses and displacements below an axisymmetric surface footing subjected to torsional loadings, has been modified to accommodate embedded footings. The material surrounding the footing can be considered as elastic, nonlinear inelastic or nonlinear inelastic including slip. Layered systems can also be treated. Good agreement was obtained in comparisons with published solutions for elastic systems, as obtained by the finite element method, and by an approximate method. In particular, comparisons were made for variations at maximum amplitude of rotation and dimensionless frequency at maximum amplitude of rotation as functions of the embedment ratio. The …

Prediction Of Loma Prieta Earthquake And Creation Of Awareness About It In Society, Arun Bapat

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

Prediction of earthquake as an exercise of academic interest is one activity. Creation of awareness about seismic disaster and its mitigation is more broad base social activity. It is necessary that the predicted seismic event is likely to occur, people in the vulnerable seismic area should be told about the utility of macroseismic, short-term reliable earthquake precursors, which could be observed by common man. The happenings involving both the above cases for Loma Prieta earthquake are discussed.

Considerations To Damage Patterns In The Marina District During The Loma Prieta Earthquake Based On Rayleigh Wave Investigation, Kohji Tokimatsu, Shoei Nomura, Shinichi Kuwayama, Shuji Tamura, Akio Abe

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

Rayleigh wave investigation is made in the Marina District to study geotechnical factors controlling the damage patterns in the Loma Prieta earthquake. A portable system has been developed for determining a Rayleigh wave dispersion curve based on the measurements of artificially induced ground vibration or microtremor. Five sites are selected along a line crossing the hydraulic fill zone in which structures and/or buried utilities were significantly damaged. An inverse analysis on the measured dispersion curves results in a cross section of shear wave velocity profiles in the District. Site amplification and liquefaction potential of each site are estimated and discussed …

General Report Session 5: Soil-Structure Interaction Under Dynamic Loading, E. Kausel, J. Roesset, A. H. Hadjian, J. Bielak, G. R. Martin

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

No abstract provided.

Classification Of Analysis Methods For Dynamic Soil-Structure Interaction, John P. Wolf

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

The various methods to perform soil-structure-interaction analysis are classified. The first classification uses as criterion the behavior (linear or nonlinear) of the structure and of the unbounded soil. The second classification distinguishes between the direct method and the substructure method, which do not necessarily lead to identical results. Within each method, however, the various procedures are mathematically equivalent. In the substructure method the dynamic stiffness representing the interaction forces of the unbounded soil is determined based on the boundary element method in the time or frequency domain. In the latter case various so-called realizations in the time domain are distinguished …

Constitutive Modelling Of Soils And Computation Of Earthquake Damage And Liquefaction, O. C. Zienkiewicz, M. Pastor, Y. M. Xie

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

For realistic modelling oi deformation and collapse of soil structures, an accurate constitutive model for the soil materials is necessary. In this paper we shall show i) how such very successful models can be obtained by the use of generalized plasticity theory; ii) the modification of such models for semi-saturated behavior; and finally iii) How incorporation of such models into a two phase computer program allows the solution of complex problems. A possible mode of failure of the San Fernando dam is included. This paper is divided into three parts according to the above.

Field And Laboratory Determination Of Soil Properties At Low And High Strains, R. D. Woods

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

Over the past quarter century many testing methods have been used to determine soil properties for dynamic analysis. Most methods had been established by the time of the writer's review (Woods, 1978), and since then, changes have been mostly evolutionary. Many field and laboratory techniques are represented in papers submitted to this conference and these are reviewed, but additional citations from literature in the intervening years has been included for completeness. No claim is made that all pertinent literature is included, but that most methods of field and laboratory testing methods are covered with representative citations.

Development Of Shear Modulus Reduction Curves Based On Lotung Downhole Ground Motion Data, C.-Y. Chang, Y. K. Tang, C. M. Mok, H. T. Tang, M. S. Power, J. C. Stepp

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

In this study, equivalent shear moduli (or shear-wave velocities) and their variations with shearing strain at the Lotung seismic experiment site were back-calculated from recorded downhole array ground motions. Ground motion data for various levels of shaking (peak ground surface accelerations ranging from 0.03g to 0.21g) recorded during seven earthquakes were used in the analyses. Results show that downhole array ground motion data can be used to infer in-situ dynamic soil properties over a wide strain range.

Mechanical Properties Of Cemented Sands Based On Inter-Particle Contact Behavior, Anil Misra, Ching S. Chang

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

The mechanical properties of cemented sands are modelled using a micromechanical approach. The derived model accounts for the packing structure, the particle properties and the contact properties.

Centrifugal Modeling Of A Pile Under Vertical Random Excitation, Lary R. Lenke, Hon-Kim Ko, Ronald Y. S. Pak

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

Data from the experimental modeling of a pile in a geotechnical centrifuge are compared with analytical results. The model pile was subjected to vertical random excitation with subsequent determination of the compliance function in the frequency domain. This compliance function was found to be consistent with theory. An absorbing boundary was used to minimize reflected wave energy from the centrifuge container boundaries.

Prediction Of Fatigue Cracking And Rutting In Asphalt Pavements By Small-Scale Centrifuge Models, M. Hossien Roghani, V. P. Drnevich, Y. H. Huang

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

This paper presents a summary of a study to investigate the feasibility of predicting fatigue cracking and rutting in full depth asphalt pavements by centrifuge modeling. This is accomplished by constructing a small-scale centrifuge model and measuring directly the resilient tensile strains at the bottom of asphalt layer and the accumulated permanent on the pavement surface under repeated loads. The purpose of using a centrifuge is to insure that the stresses and strains due to self-weight are the same in the small-scale model as in the prototype pavement. Model pavements in two different scales of 1:10 and 1:20 were constructed, …

Liquefaction Analysis By Multi-Surface Model, Satoshi Morio

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

In recent years, liquefaction phenomena induced by earthquakes have attracted considerable attention and extensive research has already been performed on various aspects. Also, many constitutive relations have been proposed in order to represent the deformation behavior during cyclic loading. These models, however, have mostly been verified by comparison stress or strain control element tests, and there have not been many numerical tests applying them to the boundary value problems. In this study, a simple and practical constitutive relation which is able to simulate the unelastic behavior of soils under multi-directional cyclic stresses is proposed. The proposed model has been introduced …

Acuta Enews March 1991, Vol. 20, No. 3

ACUTA Newsletters

In This Issue

Telecom graduate study

Greenville Tech outgrows PBX

World-calling discounts

Call for Presentations

Update on Hawaii

Listing of exhibitors

The Self-Shielding Of Fallout Gamma Rays By Terrain Roughness, Mark S. Herte

Theses and Dissertations

The study presents a first order calculation of the self-shielding of nuclear weapon fission fragment gamma rays by surface roughness (microscopic terrain irregularities). To simulate fallout particles, polymer microspheres were deposited on slides containing samples of soil, concrete and asphalt roofing shingles. Scanning electron microscopy was used to photographically map the surfaces. The thickness of surface irregularities at various angles was measured by converting the photographs to digital images. Measurements showed a dependence upon the surface type, but not upon particle size. Average values of the measurements were modelled using a homogeneous buried source. With this geometry, dose rates were …

Acuta Enews February 1991, Vol. 20, No. 2

ACUTA Newsletters

In This Issue

ACUTA gains new tax status

Stopping a runaway dialer

Just what is an engineer?

FCC ruling awaited

Party Line

In-house accounting

Centrifugal Modeling Of Leaking Underground Storage Tanks, Kuo-Neng George Chang

Theses

There are between 2 to 3.5 million Underground Storage Tanks (UST) located through this nation. Most of these tanks store gasoline and fuel oil. Many tanks in fact are or will soon be leaking, thus making them one of the major sources of groundwater contamination in USA. The fate and transport of chemicals from the leaking USTs is estimated from mathematical models. A major difficulty in these modeling efforts has been a crucial lack of information concerning the constitutive relationships governing multiphase contaminant movement.

Centrifugal modeling is an alternative to mathematical modeling, which may give an insight to the problem …