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1991

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Articles 661 - 690 of 1363

Full-Text Articles in Engineering

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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Session 8: Co-Chairman's Report, John G. Anderson Mar 1991

Session 8: Co-Chairman's Report, John G. Anderson

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

No abstract provided.

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Site Amplification Effects In The Ubaye Valley (France): Measurements And Modeling, Denis Jongmans, Michel Campillo Mar 1991

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 …

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Soil Amplification Based On Array Observation In Chiba, Japan, Lin Lu, Tsuneo Katayama, Fumio Yamazaki Mar 1991

Soil Amplification Based On Array Observation In Chiba, Japan, Lin Lu, Tsuneo Katayama, Fumio Yamazaki

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

The amplification characteristics of earthquake ground motion were investigated based on the Chiba Array observation records. The amplification of peak acceleration occurred mostly at the top soft layer and is similar for the three ground motion components. The ensemble Fourier spectrum ratio and coherence function were calculated and the amplification can be clearly seen in them. The drop of the coherence function at natural frequencies was discussed. The Fourier spectrum ratio and coherence function were also obtained using the smoothing procedure and were compared with those of the ensemble. Microtremor was measured at 11 points corresponding to the location of …

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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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A Novel Method For Synthesizing Acceleration Time History With Consideration Of Earthquake Environment, He Yang Mar 1991

A Novel Method For Synthesizing Acceleration Time History With Consideration Of Earthquake Environment, He Yang

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

A new method for generating earthquake time histories compatible with the rock response spectrum as the result of seismic hazard analysis will be presented in this paper. It is suggested that the base bank, which is composed of recorded ground motions with different response spectrum characteristics, should be used to select the initial solution. And then, modifying it iteratively to match the target spectrum. In this way, the earthquake environment could be considered.

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Application Of Fuzzy Set Theory In Option Of Response Spectra, Zhou Xiyuan, Su Jingyu Mar 1991

Application Of Fuzzy Set Theory In Option Of Response Spectra, Zhou Xiyuan, Su Jingyu

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

In order to consider the fuzziness of seismic intensity indecated by zoning map and seismic code in seismic design of structure, an innovative method in option of design spectrum in consideration of fuzziness of regional seismic hazard and site condition is presented herein. The solution of the problem can be divided into two steps: 1. to define and establish a fuzzy set for predicting and judging regional seismic hazard and site condition by applying fuzzy mathematics; 2. further to find out fuzzy vector of design spectrum depending on the fuzzy set of regional seismic hazard and site condition by applying …

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Session 9: Discussions And Replies, Multiple Authors Mar 1991

Session 9: Discussions And Replies, Multiple Authors

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

No abstract provided.

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Earthquake Damage Done At Right Angles To Epicentral Direction, Makoto Nasu Mar 1991

Earthquake Damage Done At Right Angles To Epicentral Direction, Makoto Nasu

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

In order to make clear the structures of grounds which are liable to induce earthquake damage, the relations between seismic deformation of various objects and the structures of the grounds under them, and the intersectional angles between the epicentral direction and their longitudinal axes and between the epicentral direction and the deformational directions have been investigated on the basis of many examples of such damage. Various objects such as embankments on heterogeneous grounds, for example, grounds including inclined soft soil layer or made of soft soil layer with inclined bottom, or various objects straddling soft and hard grounds, are Liable …

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Fault Induced Ground Deformations And Their Effect On Structures, Luis E. Vallejo, Mahiru Shettima Mar 1991

Fault Induced Ground Deformations And Their Effect On Structures, Luis E. Vallejo, Mahiru Shettima

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

In the United States and in many other regions of the world, structures such as earth dams are built in areas very close to strike-slip faults. For the safe design of these and other types of structures, geotechnical engineers need a reliable estimate of the ground deformations that fault movement will induce at the site of the proposed structures. In this study, the vertical ground deformations induced by the movement of one strike-slip fault segment is estimated with the use of Linear Elastic Fracture Mechanics (LEFM) theory. The ground deformations estimated using this theory and the deformations experienced by the …

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Geological And Seismicity Evaluation Of Srinagarind Dam, S. Klaipongpan, V. Chakramanont, J. Pinrode, P. Chittrakarn Mar 1991

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, …

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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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Prediction Of Characteristics Of Surface Wave For Earthquake Resistant Design, S. Nakamura, I. Suetomi Mar 1991

Prediction Of Characteristics Of Surface Wave For Earthquake Resistant Design, S. Nakamura, I. Suetomi

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

Surface waves are not considered directly in the current earthquake resistant design code of the underground lineal structure, because a method for estimating the surface wave as input motion is not established. A procedure for calculating the expected value of peak ground displacement from bedrock motion is presented in this paper; the bedrock motion is converted to Love Nave spectra by the method proposed by the authors, and Love wave spectra is converted to peak ground displacement by the method proposed newly in this paper. Input motions of the underground transmission line is estimated as an example case to compare …

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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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Array Processing Of Rayleigh Waves For Shear Structure, T. G. Barker, J. L. Stevens Mar 1991

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.

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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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Investigation Of Stress Waves Reflection Problems From A Free Surface By Dynamical Photoelasticity Method, I. Ch. Kostin Mar 1991

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.

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Leak Detection In Large Storage Tanks Using Seismic Boundary Waves, M. Kashi, K. Maser, A. Sotoodehnia Mar 1991

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 …

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Three Dimensional Wave Propagation Due To Pile Driving, S. Savidis, A. Mitakidis Mar 1991

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 …

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Use Of Rayleigh Modes In Interpretation Of Sasw Test, N. Gucunski, R. D. Woods Mar 1991

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 …

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Current Trends In Design And Analysis Of Paper Machine Foundations, Alex Sy, W. E. Mckevitt Mar 1991

Current Trends In Design And Analysis Of Paper Machine Foundations, Alex Sy, W. E. Mckevitt

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

Current trends in the design and dynamic analysis of paper machine foundations to ensure satisfactory performance are presented in this paper. Space frame foundations for modern high speed paper machines are governed by the requirements to meet stringent alignment/deflection tolerances and dynamic stiffness requirements specified by the machine manufacturer. The current design approach considers the complete machine-foundation-soil interaction. The dynamic response analysis is commonly conducted using a suitable finite element computer code in which the soil is modelled by equivalent springs. Damping is also included in the response calculation. Appropriate stiffness and damping parameters to model the foundation soil or …

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Damage Criteria For Small Amplitude Ground Vibrations, K. Rainer Massarsch, Bengt B. Broms Mar 1991

Damage Criteria For Small Amplitude Ground Vibrations, K. Rainer Massarsch, Bengt B. Broms

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

European codes and recommendations have been reviewed with respect to critical vibration levels, causing damage to buildings. It was found that the variation of the vibration threshold levels was large between the different codes. A rational approach to assess the damage caused by ground vibrations is proposed, based on wave propagation theory. The wave length appears to be the most important parameter. The damage potential was found to be greatest when the length of the propagating wave is equal to or shorter than the length of the building. The wave length can be determined from the frequency and wave propagation …

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Session 11: Discussions And Replies, Multiple Authors Mar 1991

Session 11: Discussions And Replies, Multiple Authors

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

No abstract provided.

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Dynamic Characteristics Of Crusher Supporting Structures, P. Srinivasulu, B. Sivarama Sarma, N. Lakshmanan Mar 1991

Dynamic Characteristics Of Crusher Supporting Structures, P. Srinivasulu, B. Sivarama Sarma, N. Lakshmanan

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

Ring granulator type crushers are installed in many coal handling plants over framed type supporting structures either in steel or reinforced concrete. The causes of excessive vibrations commonly reported from these installations are discussed. The paper describes, in particular, the nature and magnitudes of exciting forces to be considered for the safe design of supporting structures for such machinery. Two practical examples are illustrated - one involving an elevated steel structure and another reinforced concrete framed structure, the latter supporting multiple crushers on the same floor. Pertinent conclusions are drawn for the benefit of future designers of such installations.

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Dynamic Characteristics Of Soils In Calculation Of Vibrations Of Foundations For Machines With Periodical, Pulse And Random Loads, Vadim M. Platesky Mar 1991

Dynamic Characteristics Of Soils In Calculation Of Vibrations Of Foundations For Machines With Periodical, Pulse And Random Loads, Vadim M. Platesky

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

The paper deals with the results of the exper1mental studies performed by the author on the foundations 0.5, 2.4 and 25 sq. m in area under periodical, Pulse and random dynamic loads. Some formulas are given to determine dynamic characteristics of soils. Methods and devices for field dynamic tests of soils are described. The results of the proposed relationship check are given.

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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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