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Effects Of Earthquake Induced Liquefaction Of Sediments Stored Behind Concrete Dams, Peter M. Byrne, Li Yan, T. Srithar Mar 1991

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 …

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One- And Two-Dimensional Analysis Of Earth Dams, D. J. Elton, C. F. Shie, T. Hadj-Hamou Mar 1991

One- And Two-Dimensional Analysis Of Earth Dams, D. J. Elton, C. F. Shie, T. Hadj-Hamou

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

Earth dams may experience reduction in shear strength due to seismically induced pore pressures. Such reduction may be large enough to result in large deformations and eventual loss of the reservoir. While the analysis of embankment dams subject to earthquake loading is a complicated process, it is required for evaluation of seismic stability. In particular, the possibility of liquefaction in older, hydraulically-filled or otherwise poorly compacted dams during earthquakes presents a threat that must be addressed. This paper compares two methods of calculating the peak dynamic shear stress (critical to liquefaction evaluation) that occurs in an embankment during an earthquake. …

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Stability Analyses In The Ports Of Long Beach And Los Angeles, Allen M. Yourman Jr., Gerald M. Diaz Mar 1991

Stability Analyses In The Ports Of Long Beach And Los Angeles, Allen M. Yourman Jr., Gerald M. Diaz

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

The combined Ports of Los Angeles and Long Beach (Ports) have experienced extensive growth over the last three decades. A main feature of the expansions is the creation of new land by placing hydraulic fill behind rock retention dikes. This paper presents an overview of the recent history and state of practice of slope stability analyses performed for projects related to the expansion of the Ports. The geologic and seismic setting and typical soil conditions are also described. This paper is based on a review of geotechnical reports prepared for projects in both Ports and selected published papers. The various …

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Attenuation Laws Considering M And R Uncertainties, Sun-Rong Huo, Yuxian Hu Mar 1991

Attenuation Laws Considering M And R Uncertainties, Sun-Rong Huo, Yuxian Hu

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

Accounting for the measuring errors or uncertainties of magnitude and distance in addition to ground motion, the attenuation laws for peak horizontal ground acceleration (PGA), velocity(PGV). And displacement (PGD) are studied with a weighted consistent least-square regressional method (WCLSRM) proposed by the authors to obtain the functional relation among several random variables (R.V.). The saturation of ground motions near epicenter with respect to both magnitude and distance is also emphasized in the models. The result is that the scaling factors for distance and the linear term of magnitude in the attenuation relations regressed by the suggested method are about 16 …

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Bem-Fem Hybrid Analysis For Topographical Site Response Characteristics, Hirokazu Takemiya, Masaki Ono, Kiyotaka Suda Mar 1991

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.

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Effect Of Local Soil Stratigraphy On Microtremor Measurements, George Bouckovalas, Ioanna Krikeli Mar 1991

Effect Of Local Soil Stratigraphy On Microtremor Measurements, George Bouckovalas, Ioanna Krikeli

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

The method of microtremors has been recently applied for the microzonation of the town of alamata, in southern Greece. Results from this study are evaluated in comparison with predictions of seismic ground response obtained by 1-D wave propagation analyses. Predominant periods of microtremor are considerably lower than estimated fundamental ground periods. It is shown that a small part of the observed differences in due to soil non-linearity in connection with the small strain amplitudes induced by microtremors. The largest part appears to be due to geologic factors, namely the existence of rigid soil layers within the soft soil above the …

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Effects Of Local Soil Conditions In The 1986 Kalamata Earthquakes, George A. Athanasopoulos Mar 1991

Effects Of Local Soil Conditions In The 1986 Kalamata Earthquakes, George A. Athanasopoulos

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

Seismic ground response analyses and simplified determinations of fundamental periods of soil profiles were conducted for nine sites of the Greek coastal city of Kalamata which was struck by two destructive small epicentral distance earthquakes in September of 1986. The response analyses were performed by using the computer program LUSH here as the fundamental periods were determined by applying simplified methods suggested in recent literature. The dynamic soil properties needed in all calculations were obtained by in-situ and laboratory testing. The results of all analyses showed differentiation of response from site to site in terms of both frequency content and …

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Evaluation Of Soil Amplification At Smart1 Array, Taiwan, Mansour Niazi Mar 1991

Evaluation Of Soil Amplification At Smart1 Array, Taiwan, Mansour Niazi

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

In a recent compilation and analysis of nearly 750 accelerograms, we studied six pairs of triaxial accelerograms recorded digitally at two neighboring sites underlain by rock and soil, respectively. The distance between the two sites, both located south of the SMART1 array in northeast Taiwan, is approximately 2 km. The epicentral distances are less than 80 km. For each component, we computed the ratios of peak and spectral amplitudes recorded at the soil site to that of the rock site, for three peak parameters and 23 spectral ordinates. The mean estimates of the soil amplification for the peak parameters range …

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Pseudo- Three-Dimensional Analysis Of Cyclic Deformation Of Ground Subject To Seismic Liquefaction, Ikuo Towhata, M. D. Shafiqui Islam Mar 1991

Pseudo- Three-Dimensional Analysis Of Cyclic Deformation Of Ground Subject To Seismic Liquefaction, Ikuo Towhata, M. D. Shafiqui Islam

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

A Numerical tool was developed to evaluate the effects of differential movement which occurs at the ground surface during earthquakes. A special emphasis is placed on liquefaction of subsoils. A complicated three-dimensional analysis was avoided by using a pseudo-three-dimensional method of finite element analysis which runs on an element mesh of the ground surface topography as seen from the sky. The present analysis takes into account the nonlinear stress-strain behavior of soils, the ground softening due to pore pressure development, and the irregularity in the topography. The proposed method was applied to several cases in which buried pipelines were damaged …

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Seismic Response Of Deep Soil Profiles In The New Madrid Seismic Zone, William E. Manrod Iii, James E. Beavers, M. Joe Hunt Mar 1991

Seismic Response Of Deep Soil Profiles In The New Madrid Seismic Zone, William E. Manrod Iii, James E. Beavers, M. Joe Hunt

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

Geotechnical and geophysical investigations are being performed at a site which is located within 60 km of the epicenter of the 8.7 magnitude New Madrid February 7, 1812 earthquake. The exploration is being performed to determine the seismic response of the soil profile and to evaluate the liquefaction potential of the site. Permanent downhole instrumentation for seismic monitoring will be installed.

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General Report Session 9: Seismology: Predicting Strong Ground Motion For Design, Pierre-Yves Bard Mar 1991

General Report Session 9: Seismology: Predicting Strong Ground Motion For Design, Pierre-Yves Bard

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

The 14 papers of the session may be divided (somewhat artificially, of course) in three main subgroups: - a significant number (5) deal with the whole process of predicting strong ground motion for design, starting from geological / tectonic considerations and ending at a quantitative estimate of some ground motion parameters (peak acceleration, response spectrum,. .. ), either on a regional or national scale for zoning purposes (9.17, 9.24), or at a specific site for the design of some specific structures (papers 9.10, 9.13), or finally from a methodological point of view ( 9.13, 9.24, 9.26). - the 7 papers …

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General Report Session 8: Soil Amplification During Earthquakes And Microzonation, J. Carl Stepp Mar 1991

General Report Session 8: Soil Amplification During Earthquakes And Microzonation, J. Carl Stepp

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

No abstract provided.

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Study Of Site Response At Memphis Due To A Large New Madrid Earthquake, Shahid Ahmad, Hemand Desai, Elsa Stara-Gazetas Mar 1991

Study Of Site Response At Memphis Due To A Large New Madrid Earthquake, Shahid Ahmad, Hemand Desai, Elsa Stara-Gazetas

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

The influence of geological and geotechnical factors on potential ground motions in Memphis due to a 65km distant hypothetical M=7 New Madrid earthquake has been investigated. From the study of the seismotectonic environment and the seismicity of the region, the characteristics of the "design earthquake" are selected. A seismological model of the radiation/attenuation of the earthquake source and of the generated waves is used to generate synthetic bedrock ("hard rock") accelerograms, which are then propagated through a deep deposit of "soft-rock" to obtain input base excitations for the near-surface soil profiles. A representative soil profile for Memphis is selected from …

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Guerrero Accelerograph Array: Status And Selected Results, J. G. Anderson, A. Mendez, R. Quaas, J. N. Humphrey, R. Castro, S. K. Singh Mar 1991

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.

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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 Mar 1991

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 …

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Subsurface Conditions In Memphis And Shelby County, Tennessee, T. S. Chang, K. W. Ng, H. Hwang, C. S. Lee Mar 1991

Subsurface Conditions In Memphis And Shelby County, Tennessee, T. S. Chang, K. W. Ng, H. Hwang, C. S. Lee

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

Investigation of subsurface conditions in the Memphis and Shelby County area, located within 100 miles south of the New Madrid seismic zone, was conducted by studying the soil data of more than 8,500 boring logs in the study area. These soil boring logs were collected from government agencies and private geotechnical companies so that the overall subsurface investigation was feasible and affordable. The subsurface conditions were presented in the standardized format of representative soil logs in accordance with a grid system applied to the study area. The results of the subsurface investigation are essential for regional seismic study such as …

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Session 10: Discussions And Replies, Multiple Authors Mar 1991

Session 10: Discussions And Replies, Multiple Authors

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

No abstract provided.

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Dispersion Characteristics Of Elastic Waves In Saturated Soils, Shiming Wu, Longzhu Chen Mar 1991

Dispersion Characteristics Of Elastic Waves In Saturated Soils, Shiming Wu, Longzhu Chen

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

Based on the wave equations established by the authors, the dispersion characteristics of elastic waves in saturated soils are analyzed and verified by laboratory test and seismic survey in the field. The results can be used for determination of physical and mechanical parameters of saturated soils, such as, Poisson's ratio, depth for first appearance of full saturation, porosity and unit weight by measurement of wave velocities.

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Generalized Rayleigh Waves In Layered Solid-Fluid Media, Hua Hui Tan Mar 1991

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.

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Dynamic Considerations In The Design Of Paper Machine Foundations, J. P. Lee Mar 1991

Dynamic Considerations In The Design Of Paper Machine Foundations, J. P. Lee

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

The design of modern paper machine foundation should consider machine frame supporting foundation and underlying soil as an integrated system. For smooth operation of the machine, quality of paper and economic reasons, a dynamic analysis of the machine system should be performed. This paper discusses three most important factors in the dynamic analysis of a paper machine: (1) Soil-structure interaction effect, (2) frequency analysis, and (3) force-response analysis.

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Ground Vibration Isolated By Silo And Pile Barriers, Xian-Jian Yang Mar 1991

Ground Vibration Isolated By Silo And Pile Barriers, Xian-Jian Yang

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

Based on the model, field test and theory research, this paper puts forward the design method of ground vibration isolated by silo and pita barriers, the practical engineering calculation and the remained problems in this respect. It is pointed out that although the diameter of pile is much smaller than that L/δ shielded wave length (Woods 1978), the ground wave motion can be effectively shielded so long as the proper pile distance is to be selected. This makes it possible that the silo and pile (as well as the pile of other form and material) barriers can be used in …

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Integrated Analysis Of Turbomachinery Frame-Foundation-Soil Interaction, Madhira R. Madhav, N. G. R. Iyengar, S. Kathiroli Mar 1991

Integrated Analysis Of Turbomachinery Frame-Foundation-Soil Interaction, Madhira R. Madhav, N. G. R. Iyengar, S. Kathiroli

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

For the smooth functioning of turbomachines, the design of the rotor, the bearings, the supporting structure, and the foundation should be carried out as an integrated system. The frequency domain method in conjunction with FEM is chosen for the analysis. The modified influence matrix boundary condition method is applied to reduce the number of equations to be solved. Results for 4 idealized cases are compared. It is shown that the interaction effects are significant in the lowest frequency domain.

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Pile Driving Criteria For Construction Near An Historic Dam, L. P. Jedele Mar 1991

Pile Driving Criteria For Construction Near An Historic Dam, L. P. Jedele

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

The construction of a new road included a bridge crossing a river. The location of the bridge crossing was about 300 feet (91.5 meters) downstream from an historic dam. Prior to construction, concerns were raised about vibrations which might be generated from construction activities, especially pile driving for the new bridge abutments, and their potential effect on the integrity of the dam. As a result, a vibration study was conducted on the dam, prior to construction, to assess the vibrations generated from normal operation of the dam and from a simulated pile driving operation. Based on the simulated pile driving …

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Prediction Of Vibrations Of Footings For Highly Sensitive Devices, Werner Palloks, Werner Heidrich, Stephan Achilles Mar 1991

Prediction Of Vibrations Of Footings For Highly Sensitive Devices, Werner Palloks, Werner Heidrich, Stephan Achilles

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

When planning foundations for devices sensitive to vibrations the planned location should be investigated for vibrations. These investigations have to include the existing sources in the vicinity as for instance street or rail traffic as well as exciting devices to be installed at the same building site like compressor stations or other machines. The present paper shows a procedure to estimate the vibrations at the planned locations for sensitive devices. The procedure includes investigations of the dynamic soil properties, the decrease of the vibrations with distance, and the transfer functions of rigid footings. It takes into consideration stochastic excitation as …

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Simple Design Methods For Vibration Isolation By Wave Barriers, Tahmeed M. Ai-Hussaini, Shahid Ahmad Mar 1991

Simple Design Methods For Vibration Isolation By Wave Barriers, Tahmeed M. Ai-Hussaini, Shahid Ahmad

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

Rectangular wave barriers (open or infilled trenches) are frequently used in engineering practice to reduce the ground vibrations caused by propagating surface (Rayleigh) waves of relatively small wave lengths. This paper presents models involving simple algebraic formulas for the design of rectangular wave barriers in homogeneous soil deposits. Both vertical and horizontal ground vibrations are considered. An extensive parametric investigation was conducted using a direct boundary element method algorithm. Simple models based on the key dimensionless parameters that control the vibration screening effectiveness were then developed. The utility of such models is established through comparisons with rigorous numerical solutions and …

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Turbogenerator Foundation Analysis Under Wide-Range (Seismic In Particular) Excitation, Igor Andrianov, Vladimir Sedin Mar 1991

Turbogenerator Foundation Analysis Under Wide-Range (Seismic In Particular) Excitation, Igor Andrianov, Vladimir Sedin

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

Dynamics of turbogenerator foundation under wide-range (seismic in particular) excitation is being investigated. It is rather simple to get a solution for low- and high- frequency vibrations in case of a ribbed plate resting on elastic subgrade. As for practical purposes, it is a solution for intermediate parameter values that is of solution. It is shown here that the difficulties could be overcome by two-point fade-approximant method.

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Ground Failure During Loma Prieta Eq - Downtown Santa Cruz, Alan Kropp, Michael Thomas Mar 1991

Ground Failure During Loma Prieta Eq - Downtown Santa Cruz, Alan Kropp, Michael Thomas

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

Ground failure occurred in numerous locations in the downtown Santa Cruz area during the Lorna Prieta Earthquake. These failures included liquefaction, lateral spreading and lurch cracking. Mapping of many of these features was made within three days of the earthquake, before heavy rains obscured much of the surface evidence. Data from a United States Geological Survey study of liquefaction potential in Santa Cruz has been examined. In addition, subsurface information has been collected from several downtown subsurface exploration studies. A comparison has been made between areas where ground failure was predicted and where it occurred during the Lorna Prieta Earthquake. …

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Lifeline And Geotechnical Aspects Of The 1989 Loma Prieta Earthquake, T. D. O'Rourke, H. E. Stewart, T. E. Gowdy, J. W. Pease Mar 1991

Lifeline And Geotechnical Aspects Of The 1989 Loma Prieta Earthquake, T. D. O'Rourke, H. E. Stewart, T. E. Gowdy, J. W. Pease

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

This paper provides an overview of areas in San Francisco which were affected by soil liquefaction and significant ground deformation as a result of the Loma Prieta earthquake. The distribution of pipeline system damage is examined, and comparisons are made between 1989 and 1906 patterns of water supply damage. Special attention is given to the Marina to illustrate how the natural site conditions and artificial fills contributed to soil liquefaction and buried pipeline damage of both the water and gas distribution networks. Finally, the liquefaction potentials of natural beach and sand bar deposits, land-tipped fill, and hydraulic fill are evaluated …

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Ground Motion Characteristics Of The San Francisco Bay Area Detected By Microtremor Measurements, T. Ohmachi, Y. Nakamura, T. Toshinawa Mar 1991

Ground Motion Characteristics Of The San Francisco Bay Area Detected By Microtremor Measurements, T. Ohmachi, Y. Nakamura, T. Toshinawa

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

Microtremor measurement was done mainly in the damaged areas in San Francisco and Oakland after the 1989 Loma Prieta earthquake. The observation areas were (1) the Marina District, (2) Cypress Street, (3) the Embarcadero, and (4) South of Market District. Predominant frequency (Fp) and amplification factor (Ap) obtained from a spectral ratio between horizontal and vertical components were evaluated for each observation cite. Difference in the degree of damage in the areas (1) and (4) was coincident with difference in Ap and Fp. Significant difference could not be found in Ap and Fp between the areas (2) and (3).

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Liquefaction And Surface Settlement In The Marina District, D. Rosidi, W. B. Wigginton Mar 1991

Liquefaction And Surface Settlement In The Marina District, D. Rosidi, W. B. Wigginton

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

This paper evaluates the liquefaction potential of sands within the Marina District. Three types of underlying potentially liquefiable soil deposits are studied: (A) Hydraulic fill, (B) Artificial fill, and (C) Strawberry Island and other modern beach deposits. A liquefaction analysis for each of these deposits is conducted. It is suggested that a Peak Ground Acceleration (PGA) of approximately 0.1g is needed in the Marina District to initiate liquefaction. Relations between PGA and thickness of liquefiable soil, as well as potential surface settlement are presented. These relationships are useful for the study of expected performance of the Marina District in future …

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