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

Engineering Commons™

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

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 180181 - 180210 of 197987

Full-Text Articles in Engineering

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

Classification Of Analysis Methods For Dynamic Soil-Structure Interaction, John P. Wolf Mar 1991

Classification Of Analysis Methods For Dynamic Soil-Structure Interaction, John P. Wolf

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

The various methods to perform soil-structure-interaction analysis are classified. The first classification uses as criterion the behavior (linear or nonlinear) of the structure and of the unbounded soil. The second classification distinguishes between the direct method and the substructure method, which do not necessarily lead to identical results. Within each method, however, the various procedures are mathematically equivalent. In the substructure method the dynamic stiffness representing the interaction forces of the unbounded soil is determined based on the boundary element method in the time or frequency domain. In the latter case various so-called realizations in the time domain are distinguished …

Go to article

State Of The Art Papers: Discussion And Replies, Tzou-Shin Ueng Mar 1991

State Of The Art Papers: Discussion And Replies, Tzou-Shin Ueng

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

No abstract provided.

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

Piles Under Dynamic Loads, M. Novak Mar 1991

Piles Under Dynamic Loads, M. Novak

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

The paper deals with some of the more recent developments in pile dynamics. It reviews the progress in the analysis of single piles and pile groups, field as well as laboratory experiments and soil-pile-structure interaction. The influence of pile-soil interface is discussed and extensive references are given.

Go to article

Seismic Design Of Earth Retaining Structures, R. V. Whitman Mar 1991

Seismic Design Of Earth Retaining Structures, R. V. Whitman

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

Recent experiments, field observations and theoretical numerical studies are summarized: Where the simple conditions assumed by the Mononobe-Okabe theory are reproduced. ln tests, predictions and observations agree well. However, a retaining structure and surrounding soil are a complex dynamic system and behavior is far from simple. Emphasis has shifted somewhat away from dynamic stresses toward evaluation of residual displacements. With a good understanding of actual behavior, traditional methods may still be used except for large and unusual structures. The largest unknowns concern the behavior of cohesive soils and moderately dense to dense saturated sands.

Go to article

Earthquake Probabilities On The New Madrid Fault And The Impact Of Loma Prieta On Central U.S. Earthquake Preparedness, David Stewart Mar 1991

Earthquake Probabilities On The New Madrid Fault And The Impact Of Loma Prieta On Central U.S. Earthquake Preparedness, David Stewart

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

Reliable probabilities of future damaging earthquakes in the New Madrid Fault Zone for purposes of mitigation and response planning are not available, even though considerable thought and research has gone into this question. Generalizations sufficient for pre-earthquake planning do exist, however, which suggest the need to prepare for at least a 50% chance of a 6.0 surface wave magnitude event within a decade, but that a repeat of the massive 8.0 magnitude events of 1811-12 need not be of concern for at least another century or two. The Loma Prieta was a significant stimulus toward greater earthquake planning and preparation …

Go to article

Table Of Contents, Multiple Authors Mar 1991

Table Of Contents, Multiple Authors

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

No abstract provided.

Go to article

Conference Schedule, Multiple Authors Mar 1991

Conference Schedule, Multiple Authors

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

No abstract provided.

Go to article

Pictures And Participants, Multiple Members Mar 1991

Pictures And Participants, Multiple Members

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

No abstract provided.

Go to article

Errata, Multiple Authors Mar 1991

Errata, Multiple Authors

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

No abstract provided.

Go to article

Representative Earthquake Features In The New Madrid Seismic Zone As Seen By Participants In The March 15-17, 1991, Field Trip, David Stewart Mar 1991

Representative Earthquake Features In The New Madrid Seismic Zone As Seen By Participants In The March 15-17, 1991, Field Trip, David Stewart

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

No abstract provided.

Go to article

Application Of The Elastoplastic-Viscoplastic Bounding Surface Model To Cyclic Loading, Victor N. Kaliakin Mar 1991

Application Of The Elastoplastic-Viscoplastic Bounding Surface Model To Cyclic Loading, Victor N. Kaliakin

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

The predictive capabilities of the elastoplastic-viscoplastic bonding surface mode, with emphasis response of cohesive soils subjected to cyclic loading, are discussed herein. This model, which represents a generalized three-dimensional constitutive formulation for isotropic cohesive soils, is developed within the framework coupled elastoplasticity-viscoplasticity and critical state soil mechanics.

Go to article

Session 1: Closing Remarks, M. Pastor Mar 1991

Session 1: Closing Remarks, M. Pastor

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

No abstract provided.

Go to article

Cyclic Non-Linear Constitutive Equations For Sands, T. Doanh Mar 1991

Cyclic Non-Linear Constitutive Equations For Sands, T. Doanh

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

A series of triaxial cyclic tests are performed on Hostun sand; each test undergoes several two-way, strain-controlled cyclic loadings under drained conditions. The purpose of these tests is to investigate the behavior of this sand under complex loadings. This paper extends the previous works during the last years, and aims at showing that the non-linear incremental constitutive equations can describe the behavior of saturated sand subjected to various stress loadings in drained conditions.

Go to article

Cyclic Undrained Behavior Of An Undisturbed Gravel For Aseismic Design Of A Bridge Foundation, Fumio Tatsuoka, Shin-Lchi Yamada, Katsuhiko Yamada, Masahiko Yasuda, Susumu Manabe Mar 1991

Cyclic Undrained Behavior Of An Undisturbed Gravel For Aseismic Design Of A Bridge Foundation, Fumio Tatsuoka, Shin-Lchi Yamada, Katsuhiko Yamada, Masahiko Yasuda, Susumu Manabe

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

For the aseismic design of a pier foundation constructed on a lightly cemented dense gravel deposit of a 3,910m-long suspension bridge, cyclic and monotonic undrained triaxial tests were performed on undisturbed specimens with a diameter of 30cm taken from the deposit under a sea depth of about 55m. Using the results of the cyclic undrained triaxial tests together with irregular cyclic stresses evaluated for the design earthquake motion by a dynamic FEM analysis, maximum strains in the gravel deposit were obtained by the cumulative damage concept. The strain values thus estimated indicated a sufficiently high degree of seismic stability of …

Go to article

Cyclic Undrained Tests Along Constant Axial Stress On Hollow Cylinder, O. Hameury, T. Doanh Mar 1991

Cyclic Undrained Tests Along Constant Axial Stress On Hollow Cylinder, O. Hameury, T. Doanh

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

Cyclic hollow cylinder tests have been performed on sand and clay under undrained conditions. In order to point out the effects of the rotation of principal axes, a constant axial stress is maintained during the application of torsional shear. On this stress path, the behavior of the two materials is studied in terms of stress-strain relationship, pore pressure, failure criterion and also rotation of strain principal axes.

Go to article

Downhole Seismic Cone Analysis Using Digital Signal Processing, R. G. Campanella, W. P. Stewart Mar 1991

Downhole Seismic Cone Analysis Using Digital Signal Processing, R. G. Campanella, W. P. Stewart

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

In-situ measurement of the dynamic characteristics of surficial soils is becoming more common in geotechnical practice for prediction of ground surface motions from earthquake excitation and to evaluate foundations for vibrating equipment. Techniques for these measurements have been under development at the University Of British Columbia (U.B.C.) since 1980. The paper discusses many practical considerations with respect to equipment (sources, receivers, trigger, etc.) and procedures that can affect the interpretation and analysis of seismic cone results. A brief review is given of the cross-over method as used at UBC to determine interval shear velocity travel times from downhole seismic cone …

Go to article

Effects Of Hysteretic Shape On Dynamic Response, Per B. Selnes, Farrokh Nadim Mar 1991

Effects Of Hysteretic Shape On Dynamic Response, Per B. Selnes, Farrokh Nadim

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

The parameters determined in laboratory tests for use in dynamic analyses are usually the secant modulus and the area of the hysteresis loop. The accuracy of this approach was studied for highly non-linear behavior through analytical solutions and numerical simulations of a single degree of freedom system. Only the effect of the shape of the hysteresis loop was studied, i.e. the stiffness and the area of the loop were kept constant independent of amplitude. The study shows that irregular hysteresis may cause a significant increase in the response of the system in higher frequencies compared to what would be expected …

Go to article

Lumped Parameters In Permanent Displacement, H. V. Phuong Truong Mar 1991

Lumped Parameters In Permanent Displacement, H. V. Phuong Truong

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

New dynamic spring and damping values, which are dependent on the frequency, have been introduced into calculations of horizontal permanent displacement. The new dynamic damping value, which is inversely proportional to the circular frequency, has the same form as the material damping, while the new value of stiffness increases with increase in circular frequency. Similar methods can be used to obtain new dynamic spring and damping values for other modes of vibrations such as vertical, rocking and torsional. An analytical treatment of the coupled rocking and sliding modes is presented which considers horizontal and vertical Coulomb friction forces, two-layered soil …

Go to article

Soils Parameters And Constitutive Relations Under Multiaxial Cyclic Loading, M. Reza Salami Mar 1991

Soils Parameters And Constitutive Relations Under Multiaxial Cyclic Loading, M. Reza Salami

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

A generalized constitutive model based on the theory of plasticity is proposed and utilized to characterize stress-deformation behavior of soils and geological materials under complex and cyclic multiaxial loadings. It allows for factors such as hardenings, volume changes, stress paths, cohesive and tensile strengths and variation of yield behavior with mean pressure. It is applied to characterize behavior of soils, concrete and rocks. The Constants for the model are determined from series of available laboratory tests conducted under different initial confinements, cyclic hydrostatic preloading and stress paths obtained by using multiaxial and cylindrical triaxial testing devices. The model is verified …

Go to article

Structural Collapse Behavior Of Sands In Undrained Shear, J. D. Frost, J. L. Chameau, G. A. Leonards Mar 1991

Structural Collapse Behavior Of Sands In Undrained Shear, J. D. Frost, J. L. Chameau, G. A. Leonards

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

Results from undrained torsional shear tests are presented and used to further examine the concepts of steady state and structural collapse in sands, with emphasis on the influence of the collapse mechanism on soil behavior at steady state. It is shown that the degree to which the material collapses is dependent on the loading conditions and the initial fabric of the sand. Consequently, the steady state position in the state diagram is also function of these parameters.

Go to article

The Effect Of Frequency Of Cyclic Loading On Earth Structures And Foundation Soils, Daniel E. Normandeau, Thomas F. Zimmie Mar 1991

The Effect Of Frequency Of Cyclic Loading On Earth Structures And Foundation Soils, Daniel E. Normandeau, Thomas F. Zimmie

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

Earth dams, earth embankments, slopes, and certain foundation soils are subject to cyclic loading with an initial locked-in static shear stress due to earthquakes, blasting operations, and in some cases machine vibrations. In order to investigate the effect of the frequency of the applied cyclic loading, thirty-one Norwegian Geotechnical Institute Direct Simple Shear (NGI-DSS) tests were run. Frequencies for the applied cyclic loading of 0.2 Hz, 0.05 Hz, and 0.025 Hz were used throughout this investigation. San Fernando Sandy Silt (SFSS), from the Lower San Fernando Dam which failed in 1971, was the material tested in this study. This investigation …

Go to article

Liquefaction Criterion For Sand Deposits During Earthquake, Wu Yuejin Mar 1991

Liquefaction Criterion For Sand Deposits During Earthquake, Wu Yuejin

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

In this paper, the cyclic stress conditions for the liquefaction of sand samples and deposits are presented. The liquefaction criterion for sand deposits during earthquake is given. Finally the criterion is discussed from two aspects.

Go to article

Session 3: Opening Remarks, G. Castro Mar 1991

Session 3: Opening Remarks, G. Castro

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

No abstract provided.

Go to article

Semi-Analytical Iteration Algorithm Of Seismic Pore Pressure, Zhang Jianmin, Xie Dingyi Mar 1991

Semi-Analytical Iteration Algorithm Of Seismic Pore Pressure, Zhang Jianmin, Xie Dingyi

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

In this paper a semi-analytical iteration method for predicting the seismic pore-water pressure generation and dissipation in saturated sand layers is suggested. The fundamental formulae including three general analytical solutions under the condition of the 1-D, 2-D, and 3-D dissipation and the calculation principle are briefly presented, and then the suggested method is used in predicting the generation and dissipation of seismic pore water pressure in the 1-D saturated sand layers as an example. The suggested method provides the possibility to consider at a certain extent the change characteristics in permeability and volumetric strain of sand during the seismic action …

Go to article

Settlement Calculations Of Clay Layers Induced By Earthquake, Hiroshi Matsuda, Eiichi Hoshiyama, Sukeo Ōhara Mar 1991

Settlement Calculations Of Clay Layers Induced By Earthquake, Hiroshi Matsuda, Eiichi Hoshiyama, Sukeo Ōhara

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

A procedure to calculate the seismic settlement of clayey layers is developed based on the strain-controlled cyclic simple shear test results. By using this procedure the seismic ground settlements are estimated and also the results are compared with the observed ones. In the calculations, six types of accelerogram are used. As a result of estimations, following conclusions are obtained. (1) In the case of a horizontal soil layer of 5 m in height, the settlements are in the range from 3 to 6 cm for a maximum acceleration of about 340 gal. (2) In the case of clay deposits in …

Go to article

Dynamic Earth Pressure Distribution Behind Retaining Walls, D. M. Dewaikar Mar 1991

Dynamic Earth Pressure Distribution Behind Retaining Walls, D. M. Dewaikar

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

The point of application of dynamic active thrust and its distribution are computed using the method of slices and criterion of maximization of overturning moment of the active thrust. The computations show that point of application of the dynamic thrust is significantly influenced by such factors as wall friction and acceleration coefficients. Horizontal accelerations coupled with positive vertical accelerations (acting downwards) have the effect of moving the point of application closer to the wall base. The combination of horizontal acceleration with negative vertical acceleration produces exactly the reverse effect and generates more overturning moments even though the magnitude of corresponding …

Go to article

Stability Of Fiber Reinforced Sand Retaining Walls, Masami Fukuoka, Kakuhiro Nakayama, Shun-Ichi Lhara, Kiyohiro Okedoi, Ken-Ichirou Ozaki Mar 1991

Stability Of Fiber Reinforced Sand Retaining Walls, Masami Fukuoka, Kakuhiro Nakayama, Shun-Ichi Lhara, Kiyohiro Okedoi, Ken-Ichirou Ozaki

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

A ten meter high retaining wall made by sands reinforced with continuous fibers was constructed in 1988. Thickness of the retaining wall was 1 mat the top and 2.5 m at the bottom, and the slope was 63° at the face and 71° at the back. Earth pressure acting on the wall, displacements of the face, settlements of the fill and acceleration of the retaining wall were measured. During the construction, around the third height of the wall was displaced 15 cm in a forward direction. At the time of an earthquake, the values of the maximum horizontal acceleration at …

Go to article

Lumped-Parameter Model For Foundation On Layer, John P. Wolf, Antonio Paronesso Mar 1991

Lumped-Parameter Model For Foundation On Layer, John P. Wolf, Antonio Paronesso

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

A lumped-parameter model to represent a disk on the surface of a layer built-in at its base vibrating in horizontal, vertical, rocking or torsional motions is presented. Eight frequency-independent real coefficients determine the springs, dampers and the mass of the lumped-parameter model with two internal degrees of freedom. These coefficients are specified for various ratios of the radius of the disk to the depth of the layer and for various Poisson's ratios. To derive the mechanical properties of the lumped-parameter a systematic procedure of curve-fitting of the dynamic-stiffness coefficient up to at least twice the fundamental frequency of the layer …

Go to article

First Prev Next Last