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1991

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Articles 361 - 390 of 505

Full-Text Articles in Civil and Environmental Engineering

In Situ Torsional Cylindrical Shear Test-Laboratory Results, W. Henke, R. Henke Mar 1991

In Situ Torsional Cylindrical Shear Test-Laboratory Results, W. Henke, R. Henke

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

We present results from cyclic tests conducted in the laboratory using a prototype in situ cyclic torsional cylindrical shear geotechnical testing system. The system is intended to advance our ability to design critical systems to resist earthquakes by improving our ability to analytically predict the behavior of soil-structure-equipment systems during earthquakes. It is to do so by providing, more reliably than we feel is now possible, estimates of the in situ cyclic shear stress vs strain characteristics needed by refined earthquake analyses. These characteristics include 1) resistances to initial liquefaction, cyclic degradation, and large cyclic deformations, and 2) undegraded, nonlinear, …

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Lnsitu Measurement Of Damping Of Soils, W. P. Stewart, R. G. Campanella Mar 1991

Lnsitu Measurement Of Damping Of Soils, W. P. Stewart, R. G. Campanella

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

The Seismic Cone Penetration Test (SCPT) has been shown to give reasonable results for insitu measurements of shear wave velocity, and this paper extends this work to include measurements of damping. The relevant equations of motion are described, factors affecting amplitude decay are discussed, and the nature of damping is summarized. Consideration is given to some of the practical aspects of pre-processing of signals. Three methods of damping calculation are presented. The first two, attenuation coefficient and modified SHAKE methods, require the application of amplitude corrections, which is not straight-forward, give variable results, and indicate negative damping in a clayey …

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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 …

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Mechanical Properties Of Cemented Sands Based On Inter-Particle Contact Behavior, Anil Misra, Ching S. Chang Mar 1991

Mechanical Properties Of Cemented Sands Based On Inter-Particle Contact Behavior, Anil Misra, Ching S. Chang

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

The mechanical properties of cemented sands are modelled using a micromechanical approach. The derived model accounts for the packing structure, the particle properties and the contact properties.

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Modelling The Deformation Of Sand During Cyclic Rotation Of Principal Stress Directions, Marte Gutierrez, Kenji Ishihara, Ikuo Towhata Mar 1991

Modelling The Deformation Of Sand During Cyclic Rotation Of Principal Stress Directions, Marte Gutierrez, Kenji Ishihara, Ikuo Towhata

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

The paper presents an elastoplastic constitutive model for the deformation of sand during cyclic rotation of principal stress directions. The model employs a plastic potential theory that allows for the dependency of flow on the stress increment direction and a stress-dilatancy relation incorporating the effects of noncoaxiality. The continuous plastic deformation of sand during principal stress rotation at constant shear stress level is allowed for in the model by using a small elastic area in the stress space. The effects of cyclic stress history is modelled by using discrete surfaces of equal hardening modulus which are allowed to move with …

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Presentation Of The Porewater Pressure Buildup Using Moroto's And State Parameter, Predrag Kvasnička, Tomislav Lvšić Mar 1991

Presentation Of The Porewater Pressure Buildup Using Moroto's And State Parameter, Predrag Kvasnička, Tomislav Lvšić

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

In this paper it is attempted to generate the rise of pore water pressures in undrained strain controlled cyclic triaxial tests for various densities (void ratios), confining pressures and strain amplitudes. The results of cyclic triaxial tests on one type of standard Yugoslav sand are presented. Introducing the Moroto's parameter based on cumulative shear work normalized with confining pressure (Moroto, 1976) and a state parameter defined as a distance between initial void ratio and the steady state line (Been and Jefferies, 1985) the band of the results is narrowed and a single curve for representing the pore water pressure buildup …

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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 …

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Stiffness And Damping Of Sands In Torsion Shear, Supot Teachavorasinskun, Hiroyuki Kato, Satoru Shibuya, Noriyuki Horii, Fumio Tatsuoka Mar 1991

Stiffness And Damping Of Sands In Torsion Shear, Supot Teachavorasinskun, Hiroyuki Kato, Satoru Shibuya, Noriyuki Horii, Fumio Tatsuoka

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

A laboratory investigation was carried out into stiffness and damping of sands as sheared in a torsional shear apparatus. In the drained monotonic and cyclic loading tests, a particular care was taken of the small strain measurements in which the secant stiffness was measured over a wide range of shear strain from about 10-6 to 10-2. Despite the marked differences in the grain size and the sample preparation method among the sands, a fairly good coincidence of the secant stiffness was seen, in common, in the range of shear strain less than about 1 x 10-5 …

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The Dynamic Properties Of Carbonate Sands From Seabed, Du Jian, Wu Xiaofeng, Zhu Longgen Mar 1991

The Dynamic Properties Of Carbonate Sands From Seabed, Du Jian, Wu Xiaofeng, Zhu Longgen

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

Four kind of carbonate sands from offshore seabed together with LB sand of U.K and Fujian sand of China were tested with the Resonant Column method. The results show that the stress strain relationship in the condition of small strain can be represented with the hyperbolic model. The modulus is less than that of general sand. The cementing strength between particles of carbonate sands is weak. The breakage of particles is easy after disturbed and the density, therefore, will be increased. These properties should be further studied for engineering purpose.

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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 …

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Verification By Comparison Between Static And Dynamic Engineering Soil Parameters Evaluated By Means Of Box Tests, Jan Bencat Mar 1991

Verification By Comparison Between Static And Dynamic Engineering Soil Parameters Evaluated By Means Of Box Tests, Jan Bencat

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

A conventional track structure system consists of rails, ties, ballast, subballast and subgrade. To design a track on the basis of live load response and permanent settlement, it is necessary to have knowledge of dynamic stresses in the foundation layers of the track. It needs to determine the material properties and thus, the dynamic and permanent deformation response of the track structure. This paper gives results of the experimental measurements of static and dynamic engineering soil parameters evaluated by means of box tests, Bencat 1989.

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An Approach To Characterise Cyclic Deflection Of Piles In Calcareous Soil Media Under Offshore Wave Loading Conditions, Y. S. Golait Mar 1991

An Approach To Characterise Cyclic Deflection Of Piles In Calcareous Soil Media Under Offshore Wave Loading Conditions, Y. S. Golait

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

Behavior of piles subjected to cyclic lateral loads due to wave action is an important aspect which needs to be evaluated for analyzing and designing these piles supporting offshore structures. The study on the model piles in calcareous soil media was therefore undertaken to investigate the cyclic pile deflection response under offshore wave loading conditions. The test results are analyzed and interpreted to evolve an approach to characterize the cyclic deflection behavior of piles under critical storm loading effect and normal wave loading action.

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An Innovative Dynamic Test Method For Piles, M. C. Janes, R. C. Horvath, P. D. Bermingham Mar 1991

An Innovative Dynamic Test Method For Piles, M. C. Janes, R. C. Horvath, P. D. Bermingham

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

The system described involves using solid propellant fuels to accelerate a reaction mass of the test pile. The force required to accelerate the reaction mass upwards acts equally downward on the pile. Very high forces be may applied to the pile in a controlled, linearly increasing manner. The duration of the applied load is approximately 100 milliseconds. This rate of loading is slow enough to allow the pile and soil to react together as a composite rigid body. The effects combine to produce pile and soil response no longer dominated by the transfer of force via stress pulse (as with …

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Centrifugal Modeling Of A Pile Under Vertical Random Excitation, Lary R. Lenke, Hon-Kim Ko, Ronald Y. S. Pak Mar 1991

Centrifugal Modeling Of A Pile Under Vertical Random Excitation, Lary R. Lenke, Hon-Kim Ko, Ronald Y. S. Pak

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

Data from the experimental modeling of a pile in a geotechnical centrifuge are compared with analytical results. The model pile was subjected to vertical random excitation with subsequent determination of the compliance function in the frequency domain. This compliance function was found to be consistent with theory. An absorbing boundary was used to minimize reflected wave energy from the centrifuge container boundaries.

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Session 2: Closing Remarks, C. K. Shen Mar 1991

Session 2: Closing Remarks, C. K. Shen

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

No abstract provided.

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Deformation Of Reconstituted Clay Under Cyclic Loading, S. W. Yan, D. J. Williams Mar 1991

Deformation Of Reconstituted Clay Under Cyclic Loading, S. W. Yan, D. J. Williams

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

Reconstituted soft clay triaxial specimens were prepared by means of vacuum preloading. Both static and cyclic tests were carried out, with the specimens consolidated under different principal effective stress ratios. The test results lend themselves to incorporation in a finite element formulation, which can readily be used for calculating the deformation of soft clay under cyclic loading.

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Session 2: Discussions And Replies, Multiple Authors Mar 1991

Session 2: Discussions And Replies, Multiple Authors

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

No abstract provided.

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Large-Scale Model Forced-Vibration Test Comparison Of Test Results On Hard And Soft Ground, Takeshi Fujimori, Tomohiko Tsunoda, Kinji Akino, Masanori Izumi Mar 1991

Large-Scale Model Forced-Vibration Test Comparison Of Test Results On Hard And Soft Ground, Takeshi Fujimori, Tomohiko Tsunoda, Kinji Akino, Masanori Izumi

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

Forced-Vibration tests were performed on two large-scale same models constructed on soft and hard ground in order to investigate the effect of the hardness and the stratification of the supporting ground on the vibration characteristics of simulated reactor buildings. The soft ground is almost stratification ground, and the hard ground is almost uniform ground. The test models are RC rigid frame structure with shear walls. In the tests, sinusoidal wave excitation was applied by the excitor. The vibration characteristics of the test models, earth pressure at the bottom of the base mat and the vibration characteristics of the surrounding ground …

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Measured Full-Scale Dynamic Lateral Pile Responses In Clay And In Sand, Matti Hakulinen Mar 1991

Measured Full-Scale Dynamic Lateral Pile Responses In Clay And In Sand, Matti Hakulinen

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

In order to design machine foundations and to examine interaction between pile and soil, versatile horizontal dynamic loading tests were done to piles. In the tests both stiffness and damping values of piles were measured in overconsolidated clay and in earthfill sand. The stiffness of piles was analyzed by Winkler's spring method and the damping of piles with Gazetas' and Dobry's method. The measured and calculated values were almost the same when stiffness was considered. In damping the measured values were about 40 ... 70% of the calculated values. Very important in the calculation is to know which is the …

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General Report Session 2: Model Testing In Cyclic Loading, Mladen Vucetic Mar 1991

General Report Session 2: Model Testing In Cyclic Loading, Mladen Vucetic

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

Geotechnical earthquake engineering problems and similar soil dynamics problems usually involve random three directional cyclic loads, complicated stratification of soil deposits and geometry of supported structures, heterogeneity, anisotropy, and nonlinearity of soils, large degradation of soil stiffness and strength accompanied by equally large displacements and deformations, complex interaction between different soil deposits and between the foundation soil and the supported structure, etc. On the other hand, the empirical and analytical methods used in conjunction with standard field testing or standard laboratory cyclic testing on small specimens, which are currently available in engineering practice, are relatively simple and limited to ideal …

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Prediction Of Fatigue Cracking And Rutting In Asphalt Pavements By Small-Scale Centrifuge Models, M. Hossien Roghani, V. P. Drnevich, Y. H. Huang Mar 1991

Prediction Of Fatigue Cracking And Rutting In Asphalt Pavements By Small-Scale Centrifuge Models, M. Hossien Roghani, V. P. Drnevich, Y. H. Huang

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

This paper presents a summary of a study to investigate the feasibility of predicting fatigue cracking and rutting in full depth asphalt pavements by centrifuge modeling. This is accomplished by constructing a small-scale centrifuge model and measuring directly the resilient tensile strains at the bottom of asphalt layer and the accumulated permanent on the pavement surface under repeated loads. The purpose of using a centrifuge is to insure that the stresses and strains due to self-weight are the same in the small-scale model as in the prototype pavement. Model pavements in two different scales of 1:10 and 1:20 were constructed, …

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Shaking Table Tests On Permanent Ground Displacement Due To Liquefaction, Susumu Yasuda, Hiroyoshi Kiku, Hideo Nagase Mar 1991

Shaking Table Tests On Permanent Ground Displacement Due To Liquefaction, Susumu Yasuda, Hiroyoshi Kiku, Hideo Nagase

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

To study the mechanism of permanent ground displacement due to liquefaction, shaking table tests were conducted. Moreover, vane tests and cyclic torsional shear tests were carried out to measure the rate of decrease of the elastic modulus and the shear strength due to liquefaction. Based on these test results, the authors proposed a simplified procedure for the prediction of permanent ground displacement. Measures to counter permanent ground displacement were also discussed based on the analysis.

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Stress State And Stress Ratio Effects In Downhole And Crosshole Shear Wave Velocity Tests On Sands, Li Yan, Peter M. Byrne Mar 1991

Stress State And Stress Ratio Effects In Downhole And Crosshole Shear Wave Velocity Tests On Sands, Li Yan, Peter M. Byrne

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

The effects of stress state and stress ratio on the maximum shear modulus, obtained from in-situ downhole and crosshole shear wave velocity tests were evaluated in the model tests. The hydraulic gradient similitude method was used to increase and control the model stress level. The downhole and crosshole shear waves were generated and received along the principal stress axes using piezoceramic bender elements. It was found that (1) the shear wave velocity is dependent upon the individual principal stresses in the directions of wave propagation and particle motion, and (2) only the stress ratio defined in the plane of wave …

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Test On Behavior Of Pile Foundation In Liquefiable Soils, H. S. Liu, K. J. Chen Mar 1991

Test On Behavior Of Pile Foundation In Liquefiable Soils, H. S. Liu, K. J. Chen

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

A series of shaking table tests were conducted to clarify the compaction effects of pile driving on sandy soils, and to investigate the failure mechanism of pile foundation in liquefiable soils. The tests showed that the soil in piled zone was densified so greatly that it became non-liquefiable after pile driving. The pore pressure ratios within this zone were far lower than unit. The settlements of pile foundation were mainly caused by the movement of soil beneath pile tips to the liquefied zone which was outside the piled zone. The failure patterns of pile foundation were rather like the Meryerhoff's …

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An Alternative Method Of Measuring Spt Energy, Alex Sy, R. G. Campanella Mar 1991

An Alternative Method Of Measuring Spt Energy, Alex Sy, R. G. Campanella

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

Despite problems associated with its repeatability and reliability, the standard Penetration Test (SPT) continues to be the most widely used in-situ test for liquefaction potential assessment. There are many factors known to influence the SPT results but the most significant factor affecting the N value is the amount of hammer energy delivered into the drill rods. The existing method of SPT energy measurement consists of attaching a load cell near the top of the drill rods and measuring the force time history during hammer impact. An alternative method of SPT energy determ1nat1on based on measurement of both force and acceleration …

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Analysis Of Liquefaction Hazard Due To Earthquake, Junfei Xie, Zhaoji Shi Mar 1991

Analysis Of Liquefaction Hazard Due To Earthquake, Junfei Xie, Zhaoji Shi

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

The aim of this work is to establish a quantitative analysis approach of liquefaction hazard. Based on the microscopic field data of liquefaction it is pointed out that non-uniform settlement of building is the primary type of damages caused by sand liquefaction during earthquake. Then a computation algorithm for evaluating settlements is programmed on the basis of “Softening model” idea, and 33 liquefaction settlement events are evaluated by use of this test-computation approach. The results of these evaluations are in good agreement with the observed ones.

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Analysis Of Liquefiable Sand Deposits Using Gravel Drains, Zhi-Ying Xu Mar 1991

Analysis Of Liquefiable Sand Deposits Using Gravel Drains, Zhi-Ying Xu

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

In this paper, based on the simplified assumption about seismic pore water pressure a partial differential equation of 3-D axi-symmetrical problem which takes into account of the generation, diffusion and dissipation of seismic pore water pressure is presented. This equation is then solved by the method of separation of variables and 5-function and a mathematical formula for residual pore water pressure is obtained. The formula can be used in the calculation and design of the gravel drains installed in the sand layer prone to liquefy. The computed results by this formula are presented in a series of charts which can …

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Behavior Of Fine Sand Under Cyclic Rotation Of Principal Stresses Using The Hollow Cylinder Apparatus, Panos Dakoulas, Yuanhui Sun Mar 1991

Behavior Of Fine Sand Under Cyclic Rotation Of Principal Stresses Using The Hollow Cylinder Apparatus, Panos Dakoulas, Yuanhui Sun

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

Results of an experimental investigation on a saturated fine Ottawa Silica Sand subjected to three different types of cyclic tests are presented in this paper. The effects of principal stress rotation at a constant deviator stress on the pore water pressure buildup and the deformation characteristics of sand are evaluated in comparison with results from cyclic triaxial and cyclic torsional simple shear using the hollow cylinder apparatus. The results presented and discussed in this article, representing a small part of the experimental program, suggest that the effects of rotational shear are more important than the effects of cyclic triaxial loading …

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General Report Session 3: Deformation And Liquefaction Of Sands, Silt, Gravels And Clays, R. G. Campanella, Alex Sy Mar 1991

General Report Session 3: Deformation And Liquefaction Of Sands, Silt, Gravels And Clays, R. G. Campanella, Alex Sy

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

It has been almost 27 years since the damaging earthquakes of 1964 which occurred in Niigata, Japan and in Alaska, USA, focused the geotechnical engineers' attention to liquefaction as a major problem in earthquake engineering. Considerable research and studies have been conducted on the subject of earthquake induced liquefaction since that time and these have included field observations, laboratory experiments and model tests, and theoretical studies. Progress in understanding the liquefaction phenomenon, in the assessment of liquefaction potential, and in the solutions to mitigate the liquefaction hazard has been made, yet the problem remains controversial in many respects, as reflected …

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Dilatometer Based Liquefaction Potential Of Sites In The Imperial Valley, F. Reyna, J. L. Chameau Mar 1991

Dilatometer Based Liquefaction Potential Of Sites In The Imperial Valley, F. Reyna, J. L. Chameau

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

The liquefaction potential of several sites in the Imperial Valley, south California, is evaluated on the basis of standard penetration, cone, and dilatometer test data. The performance of the soil deposits at these sites during past earthquakes has been documented in earlier studies. Since the dilatometer parameter Kd is expected to reflect factors (e.g. fabric, prestress, preshaking, aging) affecting liquefaction potential to a certain extent (Marchetti, 1982), this paper primarily focuses on this parameter as an index for evaluating liquefaction potential. A tentative boundary curve (in terms of stress ratio vs. Kd) for evaluating liquefaction potential that …

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