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Articles 11371 - 11400 of 13029

Full-Text Articles in Engineering

Dynamical Analysis Of Soil-Piles Interaction Systems Under Earthquake Type Loadings, Kensuke Baba Mar 1991

Dynamical Analysis Of Soil-Piles Interaction Systems Under Earthquake Type Loadings, Kensuke Baba

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

In order to investigate and discuss a theoretical prediction on the seismic response of pile groups in soil-structure interaction systems, the dynamic characteristics of piles surrounded by soil ground due to earthquake type disturbances in addition to those excited by the loadings at the head of piles. This paper is concerned with a theoretical analysis which is based on the three-dimensional wave propagation theory to find dynamic interaction characteristics of elastic pile groups embedded in the viscoelastic soil stratum on a rigid basis, under external forces concentrated at the head of piles and uniformly distributed bedrock motion. In dealing with …

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Effect Of Soil Treatment On The Dynamic Response Of Machine Foundations, M. H. Maher, F. Venancio-Filho, S. J. Lacy Mar 1991

Effect Of Soil Treatment On The Dynamic Response Of Machine Foundations, M. H. Maher, F. Venancio-Filho, S. J. Lacy

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

Improvement of foundation soils using existing treatment techniques such as chemical, compaction and jet grouting can significantly enhance the general load bearing capacity of foundations. This paper describes the effect of soil treatment on the dynamic response of a rigid foundation subjected to steady-state, lCM-amplitude high-frequency vibrations, such as those encountered in machine foundation problems. Dynamic finite element analysis were performed to evaluate the effect of soil treatment as a function of treatment type and geometry. The treatment of foundation soil significantly reduced the amplitude of vibration of the foundation with the reduction being highly dependent on the type and …

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Experimental Studies On An Embedded Structure-Soil Interaction, Yuji Miyamoto, Yasuhiro Ohtsuka, Atsunobu Fukuoka, Toshiaki Nasuda, Masanori Izumi Mar 1991

Experimental Studies On An Embedded Structure-Soil Interaction, Yuji Miyamoto, Yasuhiro Ohtsuka, Atsunobu Fukuoka, Toshiaki Nasuda, Masanori Izumi

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

This paper describes the results of experimental studies performed the evaluation of the embedment effects on the dynamic characteristics of the structure and the correlation anlayses between the test results and the calculated results. The vibration tests of large scale models constructed on actual soil are carried out with the purpose of obtaining the basic data for verification study on analysis codes. In the correlation analyses, the methods used here are the sway-rocking model and the axisymmetric finite element method. These methods are confirmed to be applicable to analyse the response or the embedded structures.

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Nonlinear Time Domain Numerical Model For Pile Group Under Transient Dynamic Forces, Toyoaki Nogami, Kazuo Konagai, Jun Otani Mar 1991

Nonlinear Time Domain Numerical Model For Pile Group Under Transient Dynamic Forces, Toyoaki Nogami, Kazuo Konagai, Jun Otani

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

A computational model of soil-pile interaction behavior in pile and pile group was developed in this paper. Particular attention was paid to making the model simple and capable of taking into account nonlinear soil behavior, such as gapping and slippage between soil and pile, and cyclic behavior of soil. The model was developed within the frame work of the Winkler model defined in plane strain conditions. In order to analyze transient dynamic response in a rigorous manner, the model was formulated in the time domain using a step-by-step method. A transfer matrix approach was also adopted in the response computation. …

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Peculiarities Of Soil Structure Interaction In Construction With Artificial Bases, Mark A. Klyachko, Alexander M. Uzdin Mar 1991

Peculiarities Of Soil Structure Interaction In Construction With Artificial Bases, Mark A. Klyachko, Alexander M. Uzdin

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

A technique is suggested to increase seismic resistance of constructions by using alternative artificial bases. Two types of artificial bases are considered: a (consolidated) soil pad and a pile foundation (with or without pile grating). Criteria have been established for the foundation parameters required depending upon the foundation versus construction stiffness ratio. The construction of a consolidated soil pad 3 m thick (h~3m) with deformation module E0 > 30MPa on soils, which are referred, according to the All-Union Building Standard Specifications (SNIP, 1982), to soil category III, is shown to reduce the level of surface accelerations by a factor of …

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Seismic Effect Evaluation For Underground Space & Structures, John G. Z. Q. Wang, Jun Xiong Li Mar 1991

Seismic Effect Evaluation For Underground Space & Structures, John G. Z. Q. Wang, Jun Xiong Li

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

It is stressed in this paper that in a strong earthquake the damages of all the underground structures, chambers or any sort of underground space differed quite a lot from that on the ground surface. Numerous evidences show ground motion attenuates immensely downward with depth. However, the earthquake resistance design for underground structures still ignores this fact and sticks to the criteria of ground structures. As a result, very conservative and exhausting design for underground engineering were caused. Through a series of investigations and based on the comparison between the ground damages and the underground damages of the same site, …

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Seismic Fluidization And Foundation Behavior, R. Richards Jr., M. Budhu, D. G. Elms Mar 1991

Seismic Fluidization And Foundation Behavior, R. Richards Jr., M. Budhu, D. G. Elms

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

Field observations of seismic settlements of foundations on granular soils due to shear flow rather than densification or liquefaction are explained in terms of the concept of seismic fluidization. The theory is briefly reviewed and used to derive seismic bearing capacity factors for shallow foundations from the standard static formulas. The reduction of bearing capacity as accelerations increase triggers incremental settlement whenever the ground acceleration exceeds some critical level whose value depends on the static design factor of safety. The total seismic settlement can be computed for a particular earthquake record by a modified sliding block approach or related to …

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Soil Structure Interaction Analysis Of A Deeply Embedded Reactor Silo, Margaret Longstreth, Alan Appleford, Frederick F. Tajirian Mar 1991

Soil Structure Interaction Analysis Of A Deeply Embedded Reactor Silo, Margaret Longstreth, Alan Appleford, Frederick F. Tajirian

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

This paper reviews the seismic soil structure interaction (SSI) analysis performed for the Modular High Temperature Gas-cooled Reactor (MHTGR). The large depth to diameter ratio of the silo requires proper modeling of embedment and silo flexibility when evaluating the response of the structure to seismic loads. The carputer program SASSI was used to perform the three dimensional SSI analysis in order to take full advantage of embedment in reducing seismic response. Acceleration response spectra were computed for three soil sites at various points in the silo walls and internal vessels. The results demonstrated the effectiveness of embedment in reducing the …

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Assessment Of Dynamic Properties Of Wushantou Dam, J. C. Chern, M. T. Wang, T. S. Lee Mar 1991

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 …

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Assessment Of Seismic Stability Of Dolphin Pool Slope Of John Hart Dam, J. K. Lou, P. M. Byrne, S. J. Garner, W. F. Marcuson Iii Mar 1991

Assessment Of Seismic Stability Of Dolphin Pool Slope Of John Hart Dam, J. K. Lou, P. M. Byrne, S. J. Garner, W. F. Marcuson Iii

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

The John Hart Dam is in a high seismic risk area. To ensure dam safety, the Dolphin Pool Slope portion of the dam had to be rebuilt. Extensive field investigations and laboratory testing were conducted to obtain representative soil strength parameters for seismic stability analyses and rehabilitation design. Back analysis of the performance of the Dolphin Pool Slope under a 1946 earthquake loading confirmed the strength parameters determined from the field investigation and laboratory testing. Seismic analyses indicated that large zones of the dam could be expected to liquefy under the Maximum Credible Earthquake and, because of uncertainties regarding the …

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Automated Slope Stability Analysis Of Zoned Dams, P. K. Basudnar, Yudhbir Dhawan, R. K. Dhawan Mar 1991

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.

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Comparison Of 2-D And 3-D Dynamic Analysis Of Effective Stress Of Earth Dams, Xhou Jian, Zeng Guoxi, Wu Shiming Mar 1991

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.

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Session 7: Discussions And Replies, Multiple Authors Mar 1991

Session 7: 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 Response Analysis Of Ash-Retention Dam And Its Earthquake-Resistant Improvement, Nenghui Li, Jiamo Zhu, Zhujiang Shen Mar 1991

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.

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Modeling Of Observed Permanent Deformation At La Villita Dam, Mohamed Fadel Succarieh, Ahmed-Waeil M. Elgamal, Liping Yan Mar 1991

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 …

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Response Of Earth Dam With Underground Concrete Cut-Off Wall, Wanhong Li, Wenshao Wang Mar 1991

Response Of Earth Dam With Underground Concrete Cut-Off Wall, Wanhong Li, Wenshao Wang

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

The response of earth dam with underground concrete cut-off wall during construction, at normal operation and under earthquake action has been evaluated and some interesting research' results such as seismic permanent displacement are obtained. A new nonlinear dynamic model of cohesionless soils, consisting of unclosed hysteresis loop, moving back bone curve and static loading curve, is presented. Shear stress ratio controlled cyclic triaxial tests and ultrasonic shear wave velocity tests have been performed to measure the parameters of the model. The shear resistance at sand/concrete interface has been studied by making tests in a torsional shear testing device.

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Selection Of Method For Seismic Slope Stability Analysis, Neven Matasovic Mar 1991

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 …

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Analysis Of Site Effects At The Garner Valley Downhole Array Near The San Jacinto Fault, Sandra H. Seale, Ralph J. Archuleta Mar 1991

Analysis Of Site Effects At The Garner Valley Downhole Array Near The San Jacinto Fault, Sandra H. Seale, Ralph J. Archuleta

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

The Garner Valley downhole array is located in the geologically complicated and seismologically active San Jacinto fault zone. The choice of the site and the potential for a large earthquake there are discussed. The equipment is described in detail. The data recorded through the end of 1 April 1990 are summarized. Two large events at different locations are discussed in some detail and analyzed for amplification of the signal at the surface.

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Attenuation Of Ground Vibration On Saturated Silt Clay And Rock Bases, Xian-Jian Yang Mar 1991

Attenuation Of Ground Vibration On Saturated Silt Clay And Rock Bases, Xian-Jian Yang

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

By actual measuring and theory analysis, this paper obtains the saturated water mass density and shear modulus of saturated soil , and also the major factor affecting near source attenuation by the mteration of soil skeleton and water , the later also being the major factor affecting far source attenuation. The paper inquiries into the affect of the depth of underground water on the wave propagation. For rock base, as the wave velocity of rock body wave is high and the body wave attenuation much faster than the surface wave does, so the near source attenuated generally faster than the …

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Cellular Normal Modes: An Explanation For Alluvium Response To Earthquakes, W. R. Stephenson Mar 1991

Cellular Normal Modes: An Explanation For Alluvium Response To Earthquakes, W. R. Stephenson

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

The cellular mode concept uses simple physical reasoning to treat the response of soft sediments to earthquake shaking. It assumes that discrete areas of the ground, or "cells", have normal modes of vibration, and that each cell has its own natural frequency of vibration. Evidence indicates that shaking effects often relate directly to cell properties. Thus the 1967 Caracas, 1976 Tangshan, 1985 Mexico and 1989 San Francisco earthquakes have damage patterns, liquefaction patterns and instrumental record features which reflect the response of cellular modes. Since the introduction of the concept in 1974 a range of analytical and numerical techniques have …

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Session 8: Discussions And Replies, Multiple Authors Mar 1991

Session 8: 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 Ground Motion Amplification In Mexico City, Hsien-Hsiang Chiang, Nien-Yin Chang Mar 1991

Earthquake Ground Motion Amplification In Mexico City, Hsien-Hsiang Chiang, Nien-Yin Chang

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

The 1985 Michoacan earthquake caused extensive loss of life and severe damages. During the earthquake, the ground motions recorded at the soft clay sites were amplified by 8 to 50 times those at nearby rock sites. This study evaluates the factors influencing the seismic characteristics of the lakebed deposit in Mexico City. The essential components of response analysis are examined in both 1-D and 2-D soil systems. The amplification of ground motion can be evaluated in both 1-D and 2-D analyses. Results show that the soil property has much greater influence than the control motion on the surface ground motion. …

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Estimation Of Amplification Spectra For P And Sv Waves, Ken'ichi Abe, Kin'ichi Kasuda, Michiyasu Terada, Teruo Shimizu Mar 1991

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.

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Applications Of The Band-Limited-White Noise Source Model For Predicting Site-Specific Strong Ground Motions, Ivan G. Wong, Walter J. Silva, Robert B. Darragh, Cathy Stark, Douglas H. Wright Mar 1991

Applications Of The Band-Limited-White Noise Source Model For Predicting Site-Specific Strong Ground Motions, Ivan G. Wong, Walter J. Silva, Robert B. Darragh, Cathy Stark, Douglas H. Wright

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

Since the Band-Limited-White-Noise (BLWN) source model coupled with random vibration theory (RVT) was first developed in the early 1980's, it has been used successfully to predict strong ground motions at rock sites in different tectonic regimes. The BLWN-RVT methodology is appropriate for an engineering characterization of strong ground motions at a site since the method captures the important features of these motions in terms of peak acceleration and spectral composition and requires a minimum of input parameters. Recently, the capability to estimate strong ground motions at soil sites has been incorporated into the methodology by using RVT and plane-wave propagators …

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Geotechnical Units And The Damages Caused By Earthquakes In Valparaiso - Chile, P. Acevedo, J. Monge, M. Astroza Mar 1991

Geotechnical Units And The Damages Caused By Earthquakes In Valparaiso - Chile, P. Acevedo, J. Monge, M. Astroza

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

The geotechnical units forming the foundation soil of Valparaiso city and constituting seven zones that exhibit different stratigraphic sequences are characterized. In addition, the evolution of the artificial backfilling’s located in the seaport is reported. The damages causes by Chile Earthquake of March 3, 1985 allow to establish for each zone the MSK intensities, which are varying between 7 1/2 and 8 1/2 in the flat-ground sector of Valparaiso, and between 7 1/4 and 7 1/2 in the hills. The major intensity in the flat sector is observed in areas whose artificial backfilling’s are exhibiting greater thickness and less consistency …

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Post Evaluation On Reservoir Triggered Seismicity Of Khao Laem Dam, N. Hetrakul, B. Tanittiraporn, R. Sittipod, P. Vivattananon Mar 1991

Post Evaluation On Reservoir Triggered Seismicity Of Khao Laem Dam, N. Hetrakul, B. Tanittiraporn, R. Sittipod, P. Vivattananon

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

Investigation on reservoir associated earthquake phenomena in western part of Thailand was carried out since early 1983. After impoundment of Khao Laem Reservoir in June 1984 earthquake events had been recorded by micro seismic network around reservoir area. Evaluation of seismic parameters and earthquake pattern and the focal mechanism solutions indicate the earthquakes were triggered by impoundment and the hypocentral distribution confirm the earthquake activities along the north east direction. Results obtained from investigation clearly differentiate the reservoir induced earthquakes phenomena from natural tectonic earthquakes.

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Statistical Relations Between Intensity And Magnitude Of Southeastern United States Earthquakes, Ali A. Nowroozi Mar 1991

Statistical Relations Between Intensity And Magnitude Of Southeastern United States Earthquakes, Ali A. Nowroozi

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

The least squared, the major axis and the reduced major axis criterion are used to deduce a statistical relation between magnitude, mbLg, and intensity, I, for the earthquakes-in southeastern United States. Based on a catalog of 162 events during 1833 to 1987, with magnitudes between 1.1 and 6.9 and intensities between II and X, it is shown that the reduced major axis criterion produces: mbLg = (0.656 ± 0.058)*I + (0.402 ± 0.178), which is the best predictor equation of magnitude for the upper range of the observed intensities. The predictor equations based on the least squared …

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Impact Response Of Granular Soils, C. J. Poran, J. A. Rodriguez, K. S. Heh Mar 1991

Impact Response Of Granular Soils, C. J. Poran, J. A. Rodriguez, K. S. Heh

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

The paper describes results from an extensive experimental model study of response of dry sand to impact of a rigid pounder. In the laboratory tests a circular steel pounder was repeatedly dropped on sand contained in a large tank. Measurements included pounder acceleration and soil pressure at impact, pounder settlement, and soil densities and strains. Effects of pounder drop height, weight and contact area were investigated. A method is presented for the evaluation of global dynamic stiffness of the so1l mass affected by the impact by calculating a dynamic settlement modulus (DSM). The DSM values are determined from integration of …

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Soil Profiling By Spectral Analysis Of Surface Waves, T. Satoh, K. Yamagata, C. J. Poran, J. A. Rodriguez Mar 1991

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 …

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General Report Session 10: Wave Propagation In Soils, Chaim J. Poram Mar 1991

General Report Session 10: Wave Propagation In Soils, Chaim J. Poram

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

No abstract provided.

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