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A Variational Formulation For Classical Models Of The Slope Stability With Earthquake Effect, Petr Koudelka, Petr Procházka

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

The paper deals with an extension of application of the Method of Apriori Integration to a model of a general slope, which is partly homogeneous and which is loaded also by the earthquake effect. The most dangerous direction of the power effect of the vibration is shown and for this direction the change of safety factor is discussed. The effect of reduced shear strength is included.

Assessment Of Dynamic Properties Of Wushantou Dam, J. C. Chern, M. T. Wang, T. S. Lee

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

Accurate assessment of material properties is essential for a meaningful evaluation of the dynamic behavior of a dam. Comprehensive studies using in- situ measurement and laboratory testing techniques coupled with back calculations of dam responses in recorded motion gives the following conclusions : (1) Response in good agreement with actual motion can be obtained by using appropriate analytical models and material properties; (2) a laboratory test may give reasonable result, but allowance should be made for the effects of strain level, sample disturbance and reconsolidation, especially in loose, non - cohesive soil; (3) in- situ shear wave velocity measurement is …

Automated Slope Stability Analysis Of Zoned Dams, P. K. Basudnar, Yudhbir Dhawan, R. K. Dhawan

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

The study pertains to the pseudo-static stability analysis of zoned dams with geologic discontinuities in the foundation. Sequential unconstrained minimization technique in conjunction with Janbu's generalized procedure of slices has been used for finding the critical slip surface and the corresponding minimum factor of safety. The method has been found to be quite efficient in solving such problems.

Comparison Of 2-D And 3-D Dynamic Analysis Of Effective Stress Of Earth Dams, Xhou Jian, Zeng Guoxi, Wu Shiming

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

Presented in this paper is a comparison between the results of 2-D and 3-D dynamic effective stress analyses of a hypothetical earth dam and two real tailing dams. The study is based on a method of rigorous nonlinear dynamic analysis by taking account the interaction of the fluid and soil phase of the material.

Computation Of Dynamic Large Displacements In Earth Systems, Mohamed Fadel Succarieh, Jerry I. Lin, Ahmed-Waeil M. Elgamal

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

A model for the computation of seismically induced permanent displacements is earth structures are proposed. This model allows relative sliding between different zones of the structure under investigation. Large displacements are allowed between these zones. Elasto-plastic constitutive soil behavior is accounted for. An updated Lagrangian Jaumann Finite Element formulation is used. The proposed model is used to predict the observed behavior of LaVillita Dam during the November 15, 1975 earthquake.

Dynamic Response Analysis Of Ash-Retention Dam And Its Earthquake-Resistant Improvement, Nenghui Li, Jiamo Zhu, Zhujiang Shen

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

A nonlinear stress-strain static evaluation model and an equivalent visco-elastic dynamic evaluation model, which can simulate well the static and seismic behaviors of the ash deposit, as well as the methods for analyzing the dynamic response and for improving the earthquake-resistance of the ash-retention dam are presented and illustrated through a practical engineering project in the paper.

Dynamic Response Of Earth Dam-Foundation System, Lin Gao, Guan Fei

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

A numerical procedure is proposed to analyze the seismic response of structure resting on layered medium. By this approach the effects of the dynamic soil-structure interaction (DSSI) upon the response of earth dam on multi-layered half space subjected to seismic ground motions are studied. The dynamic responses of earth dams on rigid base are also evaluated to compare with those on a flexible homogenous half space. It is noted that great differences may arise between the results of the two cases. To investigate the influence of the truncated size of foundation in horizontal direction on the dynamic response of the …

Effects Of Earthquake Induced Liquefaction Of Sediments Stored Behind Concrete Dams, Peter M. Byrne, Li Yan, T. Srithar

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

Earthquake induced liquefaction of sediment stored behind dams can give rise to high uplift pressures which could endanger their safety. The uplift pressures depend upon the permeability and compressibility of both the sediment and the foundation and are controlled by Biot's equation. Uplift pressures are computed for a single dam and foundation with a range of properties. The results show that for the conditions analyzed, the uplift pressures are largely controlled by the foundation permeability with the largest uplift pressures occurring for the highest foundation permeability. The possibility of liquefied sediment flowing into fissures in the foundation rock is also …

Inelastic Seismic Response Of San Fernando And Santa Felicia Dams, Elsa Stara-Gazetas, Ricardo Dobry

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

A simplified method of inelastic seismic analysis of earth dams developed by the authors is used to study the response of the San Fernando and Santa Felicia dams to accelerograms recorded in the 1971 San Fernando Earthquake. The method involves two separate stages. In stage I, the dam is discretized into finite elements and is subjected to horizontal static inertia-like forces; its nonlinear deformation is computed using a plane strain code, while the applied horizontal forces are gradually increased until large enough strains develop in most elements of the dam. The results of this analysis are utilized to derive realistic …

Measured And Calculated Dynamic Response Of Rock-Fill Dam, Lelio H. Mejia, Katherine Fung, David W. Sykora, Joseph P. Koester, Mary E. Hynes

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

The U.S. Army Corps of Engineers recently completed a seismic stability assessment of the Ririe Darn and Reservoir Project located near Idaho Falls, Idaho. Ririe Darn is an earth- and rockfill darn with a central impervious core constructed between 1966 and 1975 in a narrow canyon of Willow Creek. A geologic and seismologic study indicated that the controlling maximum credible earthquake (MCE} is a Magnitude 7.5 earthquake at a distance of 8 km from the darn. The seismic stability analysis included a dynamic response analysis of the darn using two-dimensional finite element procedures. Empirical relations derived from the observed response …

Modeling Of Observed Permanent Deformation At La Villita Dam, Mohamed Fadel Succarieh, Ahmed-Waeil M. Elgamal, Liping Yan

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

The observed behavior of La Villita dam in Mexico during five different earthquakes which have occurred in the period 1975-1985 is analyzed. Asymmetry observed in the recorded crest acceleration time histories is interpreted to be due to localized stick-slip behavior below the recording instrument. Yield acceleration associated with each stick-slip event can be inferred directly from these crest records. Values of observed average yield accelerations for the November 15, 1975 and September 19, 1985 earthquakes are used to predict the observed horizontal displacements during these earthquakes. Response of other soil systems involving stick-slip deformations during dynamic loading is also briefly …

Nonstationary Stochastic Seismic Response Analysis For Earth And Rockfill Dams, Wu Zaiguang, Lin Gao, Han Guocheng

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

In this article, the time domain madal analysis technique for evaluating the nonstationary responses of linear systems is combined with the equivalent linearization approach for determining the stationary responses of nonlinear soil structures. A new analysis method is formed and the nonstationary responses of the earth and rockfill dam are calculated. The results from nonstationary analysis are compared with the ones from the stationary computations. The effectiveness of nonstationarity of input and output is investigated and the relevant conclusions are given.

Seismic Stability Of Hillslopes In Greater Cincinnati Area, M. Zoghi, A. Bodocsi

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

Slope stability problems involving colluvia on shale bedrock are common in the Greater Cincinnati Area. The behavior of these hillslopes during earthquakes is, however, not known. This gives cause to speculation whether they are vulnerable to earthquake vibrations. In order to verify the response of these slopes to earthquake induced ground motions, representative composite clay shale samples obtained from a typical colluvial hillside in Cincinnati were tested in a cyclic direct shear apparatus which was attached to a load cell from the MTS piston actuator. The samples were initially consolidated under a selected normal pressure and then sheared until residual …

Selection Of Method For Seismic Slope Stability Analysis, Neven Matasovic

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

The seismic stability of natural slopes in clayey materials is a subject about which much uncertainty still exists. Therefore, selection of the method for the seismic slope stability analysis is an important part of solving the problem. In this paper the basic elements of the pseudo-static method, the sliding block method and the Ishihara's method are discussed. A case history of seismic stability analysis of an Adriatic coast flysch slope has been employed to evaluate the applicability and reliability of these methods. The slope is treated as an infinite slope. Although no definitive conclusions can be drawn from a single …

General Report Session 7: Stability Of Slopes And Earth Dams Under Earthquakes, J. Lawrence Von Thun

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

The papers received for this session may be classified into five general topic areas; the number of papers in each subtopic area is shown in parentheses.

1. Slope stability analysis incorporating dynamic loading Ÿanalysis methods (3)

Ÿdynamic effects on soil properties (2)

Ÿcase study (1)

2. Dynamic response of embankment dams

Ÿanalysis methods (5)

Ÿcase studies (2)

3. Dynamic deformation analysis

Ÿanalysis methods adapted for a specific case (3)

Ÿcomparison of analysis methods (1)

4. Dynamic deformation or stability analysis incorporating pore pressure development or liquefaction considerations Ÿanalysis methods (3)

Ÿanalysis methods developed for a specific case (2)

Ÿcase history …

Bem-Fem Hybrid Analysis For Topographical Site Response Characteristics, Hirokazu Takemiya, Masaki Ono, Kiyotaka Suda

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

This paper concerns an amplification of seismic ground motions by a certainly shaped surface soil deposits in view of its topographical configuration. Different hybrid methods of the boundary element method (BEM) and the finite element method (FEM) are used for the two-dimensional (2- D) analysis. In the analysis, the far field impedance is first evaluated by BEM then it is incorporated into the near field FEM analysis based on the weighted residual method. The steady state responses for different types of harmonic incident waves are investigated. Some useful findings are pointed out in comparison with the one-dimensional (1-D) results.

Session 8: Discussions And Replies, Multiple Authors

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

No abstract provided.

Estimation Of Amplification Spectra For P And Sv Waves, Ken'ichi Abe, Kin'ichi Kasuda, Michiyasu Terada, Teruo Shimizu

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

In order to evaluate site effects on strong ground motions, the earthquake motions obtained from the vertical array deploying toward the depth of 400m and a part of the satellite array around its array are used. Dividing horizontal and vertical Lime histories into two potions which have primary and secondary arrivals respectively, their amplification spectral ratios between particular two points in and around the vertical array are examined as a problem of incident P- and SV-wave into stratified structures.

Session 8: Opening Remarks, Ricardo Dobry

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

No abstract provided.

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 …

Session 9: Discussions And Replies, Multiple Authors

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

No abstract provided.

Guerrero Accelerograph Array: Status And Selected Results, J. G. Anderson, A. Mendez, R. Quaas, J. N. Humphrey, R. Castro, S. K. Singh

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

This paper summarizes the history and rational for installation of the Guerrero accelerograph array. The array is producing unprecedented quantities of high quality digital strong motion data. Recent research using the array data has included studies on attenuation, site effects, scaling of spectra with magnitude, the ratio of vertical to horizontal accelerations, and the source of the September 19, 1985 earthquake.

Seismic Risk Analysis For A Site Along The Gorda Segment Of The Cascadia Subduction Zone, Ronald C. Chaney, Guy Conversano, Gary Carver, David N. Lindberg, Frank Bickner

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

A seismic risk evaluation was conducted on a site near Eureka, California. The site was subject to potential earthquake loading from a number of sources. These sources were: (1) Mendocino Fracture Zone, (2) Gorda Segment of the Cascadia Subduction Zone, (3) Little Salmon thrust fault under the site, (4) Mad River Fault Zone, and (5) Intra plate west - Gorda Plate. The geology of thrust faults in Northern California is examined along with that of the Mendocino Fracture Zone, and the southern section (Gorda Segment) of the Cascadia subduction zone. A trench log showing a splay of the Little Salmon …

Array Processing Of Rayleigh Waves For Shear Structure, T. G. Barker, J. L. Stevens

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

Site response to earthquakes is strongly dependent on shallow shear wave velocity structure β(z), and evidence suggests that soil strength and liquefaction potential depends on it as well. We have determined β(z) at several sites by inversion of dispersion data from Rayleigh waves recorded on linear arrays of geophones using artificial sources. Improved methods have been developed for extracting phase and group velocities that lead to significantly more stable and accurate inversion results.

Session 10: Discussions And Replies, Multiple Authors

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

No abstract provided.

Generalized Rayleigh Waves In Layered Solid-Fluid Media, Hua Hui Tan

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

A finite-element method for the propagation of Rayleigh-type waves in layered solid-fluid media is presented. The method uses displacement as the only parameter to describe the solid and the fluid motions. A penalty function method and a selective integration technique are employed to change the elastic coefficient matrix of fluid from singular to nonsingular. Results obtained from the proposed method agree well with those obtained from available analytical solutions. The method can be used to study the propagation of Rayleigh-type waves in a two-dimensional, irregular solid-fluid system.

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 …