Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

1991

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 691 - 720 of 1363

Full-Text Articles in Engineering

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 …

Go to article

Ground Vibration Isolation Using Gas Cushions, K. Rainer Massarsch Mar 1991

Ground Vibration Isolation Using Gas Cushions, K. Rainer Massarsch

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

A new ground vibration isolation method is described, which uses inflated, flexible cushions. The isolation cushions have therefore a low impedance and act as vibration reflectors in the ground. Practical aspects, such as the production of the gas cushions screen, the installation method and the gas-tightness of the gas cushions are discussed. The screen can be installed to great depth, using the well-proven slurry trench technique. After installation, the trench is filled with a self-hardening cement-bentonite grout, which creates a plastic, water-tight protection layer around the cushions and assures the long term stability of the screen. The gas cushion screen …

Go to article

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.

Go to article

Pile Driving Analysis: Two-Phase Finite Element Approach, P. Hölscher Mar 1991

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. …

Go to article

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 …

Go to article

Predicting Vibrations Of Soil And Buildings Excited By Machine Foundations Under Dynamic Loads, Mark Svinkin Mar 1991

Predicting Vibrations Of Soil And Buildings Excited By Machine Foundations Under Dynamic Loads, Mark Svinkin

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

This paper presents a new method that predicts the vibrational effects on existing soil, building and equipment from a designed machine foundation when it will be installed at a specific site. The method requires development of certain experimental data at an industrial site and subsequent computerized data reduction. The results are complete vibro-records at the locations of interest. The basic prerequisite of the suggested method is an experimental determining of impulse responses of soil and structures. The use of this response gives to an engineer a chance to consider heterogeneity and multiformity of soil properties. The accepted assumptions have been …

Go to article

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 …

Go to article

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 …

Go to article

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.

Go to article

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. …

Go to article

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 …

Go to article

Liquefaction Of Soils In The 1989 Loma Prieta Earthquake, Raymond B. Seed, Michael F. Riemer, Stephen E. Dickenson Mar 1991

Liquefaction Of Soils In The 1989 Loma Prieta Earthquake, Raymond B. Seed, Michael F. Riemer, Stephen E. Dickenson

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

The Loma Prieta Earthquake of October 17, 1989 was the most costly single natural disaster in U.S. history, resulting in losses of $7 to $9 billion, and claiming 63 lives. These damages were concentrated mainly at a number of distinct sites comprising a relatively small fraction of the affected region, as local site conditions and related geotechnical factors exerted a major influence on damage patterns and loss of life in this catastrophic event. This paper discusses one of these geotechnical factors, the widespread occurrence of soil liquefaction during the earthquake, as well as the associated damages and the resulting lessons …

Go to article

Prediction Of Loma Prieta Earthquake And Creation Of Awareness About It In Society, Arun Bapat Mar 1991

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.

Go to article

Site Stratigraphy And Its Effects On Soil Amplification In The Greater Oakland Area During The October 17, 1989 Loma Prieta Earthquake, J. David Rogers Mar 1991

Site Stratigraphy And Its Effects On Soil Amplification In The Greater Oakland Area During The October 17, 1989 Loma Prieta Earthquake, J. David Rogers

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

No abstract provided.

Go to article

The Loma Prieta Earthquake: Implications Of Structural Damage, S. A. Mahin Mar 1991

The Loma Prieta Earthquake: Implications Of Structural Damage, S. A. Mahin

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

The Loma Prieta earthquake provides a wealth of information on the seismic response of a wide variety of structures over a large metropolitan area. Soil amplification at sites distant from the epicenter contributed significantly to the substantial damages developed during the earthquake. Because of the large shaken area, the earthquake provides much useful information for all those interested in earthquake engineering. Structural damages resulting from the earthquake are reviewed herein with emphasis on buildings and bridges. Implications for modern design and retrofit methods are highlighted. Emphasis is placed on the need to carefully consider soil conditions, to treat the structure …

Go to article

A Study On Pile Forces Of A Pile Group In Layered Soil Under Seismic Loadings, Hasegawa Masayuki, Nakal Shoichi Mar 1991

A Study On Pile Forces Of A Pile Group In Layered Soil Under Seismic Loadings, Hasegawa Masayuki, Nakal Shoichi

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

Characteristics of pile forces under seismic loadings are discussed from view points of the inertial interaction due to the mass effect of a superstructure and the kinematic interaction due to the resistance effect of piles against soil motions. A typical building supported on a pile group embedded in a layered soil, which has two- and four layer profiles, is chosen for studying the pile forces which imply the shearing force and bending moment. The earthquake response analysis is performed in accordance with the substructure method, in which the group effect of piles in the layered soil is appropriately included by …

Go to article

Characteristics Of Vertical Ground Motions Recorded During The Lorna Prieta Earthquake, Marshall Lew Mar 1991

Characteristics Of Vertical Ground Motions Recorded During The Lorna Prieta Earthquake, Marshall Lew

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

A study of a limited number of vertical ground motion acceleration-time histories recorded during the Loma Prieta earthquake of October 17, 1989 has been made. It has been found that maximum vertical ground motions may be greater than the horizontal ground motions in the near vicinity of the fault rupture zone. The limited records suggest that there is more spectral energy at very short structural periods in the vertical ground motions as compared with the horizontal ground motions. At longer periods, the vertical energy is significantly less, however, there is an increasing trend for very long structural periods.

Go to article

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 Mar 1991

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 …

Go to article

Contributed Papers: Discussions And Replies, T. Kagawa Mar 1991

Contributed Papers: Discussions And Replies, T. Kagawa

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

No abstract provided.

Go to article

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).

Go to article

Investigation Of Sanitary Landfill Slope Performance During Strong Ground Motion From The Loma Prieta Earthquake Of October 17, 1989, Mervin E. Johnson, Joan Lundy, Marshall Lew, Monte E. Ray Mar 1991

Investigation Of Sanitary Landfill Slope Performance During Strong Ground Motion From The Loma Prieta Earthquake Of October 17, 1989, Mervin E. Johnson, Joan Lundy, Marshall Lew, Monte E. Ray

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

This paper evaluates the performance of landfill slopes (refuse fill slopes) during strong ground motion from the October 17, 1989 Loma Prieta Earthquake (M7.1) that affected the Santa Cruz Mountains - San Francisco Bay region. The earthquake's occurrence in a highly populated area that contains the waste disposal sites for this large population offered a unique opportunity to review the performance of slopes on the landfills. Current state and federal regulations require the analysis of stability of landfills under seismic loading. To date, these evaluations have relied on gross simplified assumptions. This paper examines whether these assumptions are reasonably correct. …

Go to article

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 …

Go to article

On The Site Amplification Characteristics In San Francisco Bay Region Due To The 1989 Loma Prieta Earthquake Type Loadings, Kesuke Baba, Yutaka Inoue, Takashi Nishigaki Mar 1991

On The Site Amplification Characteristics In San Francisco Bay Region Due To The 1989 Loma Prieta Earthquake Type Loadings, Kesuke Baba, Yutaka Inoue, Takashi Nishigaki

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

A large earthquake occurred in the Santa Cruz mountains, California, on 17 October 1989, and many structures and facilities in the San Francisco Bay region suffered fatal damage from the seismic motion. In order to evaluate the ground amplification characteristics in the region, the practical method of representing the seismic wave field may be necessary. This paper is concerned with a theoretical analysis and numerical evaluation based on the wave propagation theory to find the dynamic characteristics of the slightly sedimental basin around the San Francisco Bay due to the Loma Prieta earthquake type excitations. Numerical examples of this system …

Go to article

Sanitary Landfill Performance During The Loma Prieta Earthquake, Dennis Buranek, Sangeeta Prasad Mar 1991

Sanitary Landfill Performance During The Loma Prieta Earthquake, Dennis Buranek, Sangeeta Prasad

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

The October 17, 1989, Loma Prieta earthquake subjected a number of solid waste or sanitary landfills to significant shaking. The performance of sanitary landfills during large earthquakes is of great interest to the public, state and federal agencies, and the landfill owners. The observed performance of six sanitary landfills located within the Lorna Prieta earthquake damage zone is compared with the performance predicted by a commonly used deformation analysis technique. The six landfills were inspected immediately after the October 17, 1989, magnitude 7.1 earthquake. Damage and evidence of slope movement, or lack thereof, was recorded. The mean peak ground accelerations …

Go to article

Seismic Design Basis — The Uk Regulatory Position For New Nuclear Reactors, C. M. Patchett, R. J. Stubbs Mar 1991

Seismic Design Basis — The Uk Regulatory Position For New Nuclear Reactors, C. M. Patchett, R. J. Stubbs

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

The purpose of this paper is to outline the seismic regulatory requirements relating to the site licensing of new nuclear power installations in the UK, and to describe the background and justification of the seismic design basis level for such installations. It outlines the potential seismic related hazards which should be covered, the factors which are considered important in establishing the level of hazard under consideration, and the techniques which could be used for hazard evaluation. In addition, the paper covers the level of uncertainty associated with the methodology and analytical techniques used in evaluating the seismic hazards.

Go to article

Site Effects In The Loma Prieta Earthquake And Comparison With An Earthquake Intensity Prediction Method, Hatukazu Mizuno, Akio Abe Mar 1991

Site Effects In The Loma Prieta Earthquake And Comparison With An Earthquake Intensity Prediction Method, Hatukazu Mizuno, Akio Abe

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

Strong motion records of the Loma Prieta Earthquake of October, 17, 1989 have been analyzed in comparison with epicentral distances and types of soil deposits, and site effects and attenuation relations have been studied. Site effects are significantly recognized in the earthquake, as usually found in Japanese earthquakes. And validity of the U.S. seismic intensity prediction method that Association of Bay Area Governments (ABAG) adopted to prepare some earthquake preparedness maps has been examined on the basis of the Loma Prieta Earthquake data. Finally, soil damping of San Francisco Bay Area has been evaluated from the strong motion records.

Go to article

The Liquefaction Sand Boils In The San Francisco Marina District During The 1989 Loma Prieta Earthquake, J. P. Bardet, M. Kapuskar Mar 1991

The Liquefaction Sand Boils In The San Francisco Marina District During The 1989 Loma Prieta Earthquake, J. P. Bardet, M. Kapuskar

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

The paper presents and analyzes the observations of the sand boils that emerged in the Marina District after the Loma Prieta Earthquake of October 17, 1989. The sand boils left behind by liquefaction revealed an old lagoon, the periphery of which had experienced severe damage in the 1906 San Francisco earthquake. The buildings in the Marina District were damaged primarily as the liquefied ground spread laterally along the shoreline of the 1906 lagoon that was filled to host the 1915 Panama-Pacific International Exposition in San Francisco. The present work infers that the sand boils are not random phenomena but instrumental …

Go to article

Centrifuge Modeling For Dynamic Geotechnical Studies, R. S. Steedman Mar 1991

Centrifuge Modeling For Dynamic Geotechnical Studies, R. S. Steedman

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

The field of dynamic centrifuge modelling has developed rapidly over the past decade, with international interest in both earthquake and blast modelling. The paper discusses the proliferation of facilities and the insight that can be gained from the interpretation of dynamic model test data now available using hand calculations and advanced techniques of digital signal processing.

Go to article

Constitutive Modelling Of Soils And Computation Of Earthquake Damage And Liquefaction, O. C. Zienkiewicz, M. Pastor, Y. M. Xie Mar 1991

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.

Go to article

Earthquake Geotechnology In Offshore Structures, R. G. Bea Mar 1991

Earthquake Geotechnology In Offshore Structures, R. G. Bea

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

Current developments in earthquake geotechnology in offshore structures are summarized. These developments include measurements of sea floor and platform motions induced by earthquakes and analyses of platform structure and foundation systems. Results from these recent developments are illustrated.

Go to article

First Prev Next Last