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Assessment Of Liquefaction Potential And Post-Liquefaction Behavior Of Earth Structures: Developments 1981-1991, W. D. Liam Finn

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

Significant developments in procedures for evaluating liquefaction potential and the post-liquefaction behaviour of earth structures are reviewed for the period 1981-1991. Particular attention is paid to the re-valuation of the liquefaction induced slide in the San Fernando Dam following the 1971 earthquake. The findings of this study have had a major impact on engineering practice.

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

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

For realistic modelling oi deformation and collapse of soil structures, an accurate constitutive model for the soil materials is necessary. In this paper we shall show i) how such very successful models can be obtained by the use of generalized plasticity theory; ii) the modification of such models for semi-saturated behavior; and finally iii) How incorporation of such models into a two phase computer program allows the solution of complex problems. A possible mode of failure of the San Fernando dam is included. This paper is divided into three parts according to the above.

Effects Of Soil-Structure Interaction For Structures Subjected To Earthquakes, A. S. Veletsos

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

An extended summary is presented of a state-of-the-art report on the subject matter. The report parallels one presented at the Fourth U. S. National Conference on Earthquake Engineering, in May 1990.

Field And Laboratory Determination Of Soil Properties At Low And High Strains, R. D. Woods

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

Over the past quarter century many testing methods have been used to determine soil properties for dynamic analysis. Most methods had been established by the time of the writer's review (Woods, 1978), and since then, changes have been mostly evolutionary. Many field and laboratory techniques are represented in papers submitted to this conference and these are reviewed, but additional citations from literature in the intervening years has been included for completeness. No claim is made that all pertinent literature is included, but that most methods of field and laboratory testing methods are covered with representative citations.

Geotechnical Lessons Learned From Mexico And Other Recent Earthquakes, Emilio Rosenblueth, Efrain Ovando

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

This paper describes the most relevant effects of the September 1985 earthquakes on Mexico City. It discusses the results of recent exploration and research on regional geology, local site conditions and site response analyses, basic soil properties, and observation of actual behavior of soil-foundation-structure systems. The paper shows the impact of these investigations upon new - building code requirements, on general design practice and on the specialist's perception of earthquake behavior of Mexico City's subsoil. Recent earthquakes recorded in and around Mexico City have contributed insight into some of the unresolved questions left after the experience of 1985. Damaging earthquakes …

Preface, Shamsher Prakash

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

No abstract provided.

Welcoming Remarks, Joseph E. Minor

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

No abstract provided.

Cyclic Undrained Behavior Of Saturated Sand Under Monotonic Loading, Hiroshi Matsuzawa, Masahiro Sugimura

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

In order to investigate undrained behavior of saturated sand, three types of undrained triaxial tests were performed for saturated Toyoura sand, i.e., cyclic loading test with (DTU-test) and without (DU-test) constant initial shear stress and tests in which constant rate axial strain and cyclic axial stress were applied to a specimen simultaneously (DCU-test). In DCU-tests, three types of failure were observed, i.e.; 1) perfectly liquefied in the case of relatively loose sand, 2) initially liquefied, but shear failure was induced after strength recovery for succeeding loading in the case of relatively dense sand, and 3) shear failure was induced without …

Degradation Of Saturated Clays After Cyclic Loading, Tamotsu Matsui, Mohamed A. Bahr, Nobuharu Abe

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

This paper presents a part from a series of tests performed to evaluate the static shear behavior of normally consolidated and over-consolidated clays after cyclic loading effect. The results demonstrated that the static undrained stress-strain behavior of these types of clays was affected by their relative stiffness. Based on the equivalent over-consolidation hypothesis and the experimental results it was able to construct the shear characteristics degradation relationships for the normally consolidated clays. The predicted results were compared with the measured test data and their well agreement was confirmed.

GMax From Pressuremeter Tests: Theory; Chamber Tests; And Field Measurements, Peter M. Byrne, Francisco Salgado, J. A. Howie

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

A method of analysis to predict the in situ maximum shear modulus G_max,0 from self-boring pressuremeter unload tests is presented. The method considers both the stress and void ratio changes induced by pressuremeter loading and the nonlinear stress-strain response upon unloading. The results are presented in the form of a chart that allows G_max,0 to be determined from the equivalent elastic unload modulus, G*, for a wide range of loading and unloading conditions. The analysis procedure is checked with chamber tests and field data and the results are found to be in good agreement provided factors to account …

Modeling The Monotonic And Cyclic Viscoplastic Soil Behavior, Ronaldo I. Borja

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

We describe a class of viscoplastic constitutive models capable of simulating the monotonic and cyclic rate-dependent soil behavior. These models are developed by enriching their inviscid counterparts with a viscous character to model the irreversible deformation that develops with time. The viscoplastic strain rate is of the Duvaut-Lions type whose magnitude increases with the distance of the stress point from its projection onto the inviscid solution. With appropriate choice of an inviscid elasto-plastic soil model, one can generate quasipreconsolidation effects during creep and account for the influence of frequency on the shape and width of hysteresis loops formed during cyclic …

General Report Session 1: Static And Dynamic Soil Parameters And Constitutive Relations Of Soils, Peter M. Byrne, Li Yan

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

The soil parameters that are commonly of interest in dealing with earthquake and soil dynamics problems are:

1) The maximum shear modulus G₀, or the shear wave velocity, V_s.

2) The variation of secant shear modulus with shear strain level, G/G₀ vs γ.

3) Equivalent viscous damping as a function of strain.

4) Other parameters such as, dilatometer modulus, normalized SPT or CPT value, state parameters, formation factor.

In terms of constitutive relations the following models have been used:

1) Linear elastic (total stress) - appropriate at very small strains < 10^-3%.

2) Equivalent linear …

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 …}

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 …

Session 2: Closing Remarks, C. K. Shen

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

No abstract provided.

Session 2: Discussions And Replies, Multiple Authors

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

No abstract provided.

Laboratory Tests On Embedded Reactor Building On Soft Ground, Ltaru Kurosawa, Shohara Ryoichi, Kinji Akino, Masanori Izumi

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

Model tests using shaking table and impulse hummer were performed to confirm analysis tools currently used in Japan for the seismic design of a reactor building embedded in soft ground. The models are made of a silicone rubber ground and an aluminum building. Embedment depths of the foundation are varied. Comparison between test results and analytical results is discussed in terms of impedance functions, foundation input motions and structure responses.

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 …

Liquefaction Tests By A Laminar Box In A Centrifuge, Kichio Suzuki, Ryouichi Babasaki, Yoshio Suzuki

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

A new laminar box constructed with aluminum frames of 24mm wide and 10mm thick for model shaking tests on liquefaction phenomenon of soft saturated sandy soil in centrifugal gravity field was manufactured. The box was designed to develop shear distortion in the soil unimpeded by a rigid-type container. Liquefaction tests were performed on horizontally laid soft saturated sand and obtained the same results as Tokimatsu and Yoshimi 1983.

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, …

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.

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 …

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.

Dynamic Properties Of Fine-Grained Coal Refuse, C. Robert Ullrich, Barry K. Thacker, Nancy R. Roberts

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

A simplified method of slope stability analysis is presented for upstream-constructed coal tailings dams subjected to earthquake shaking. The method employs a conventional method of slices approach, in which dynamic loads are represented as psuedostatic forces applied to each slice. Excess pore water pressures are estimated from cyclic triaxial tests performed on specimens of fine coal refuse. Cyclic triaxial test results are presented for fine coal refuse materials from six sites in the western Appalachian region. Measured excess pore water pressure values appear to be influenced by fine coal processing procedures, although material plasticity and grain characteristics are also important. …

Evaluation Of Liquefaction Potential For An Earth Dam Site, Bhagwat V. K. Lavania, J. N. Sharma, S. Mukerjee

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

The foundation of the proposed Polavaram Earth and Rockfill Dam (India) has a sand deposit about 15 to 30 meters deep. The medium size sand is poorly to uniformly graded having relati.ve density in the range of 40-45% and angle of internal friction 30°. Standard Penetration Tests have been conducted in 22 bore holes at site and the N-counts have been observed to range between 4 to 111. The liquefaction potential of deposit under maximum credible earthquake (MCE) for the site has been evaluated by analyzing the data on the basis of prevailing empirical approaches and by the results of …

Fault Processes And Liquefaction In The Marine Environment, Ronald C. Chaney

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

No abstract provided.

An Elastoplastic Model For Sand Liquefaction, Limin Zhang, Ting Hu

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

The stress-dilatancy relations of sand for the stress paths involved in a complete periodic stress cycle are set up. The plastic potential functions for' each loading stage are derived consequently. Based on the idea of using a stress-strain relationship as an alternative strain-hardening law, the drained volume changes under different effective stress paths are derived and verified. A pore pressure generation mechanism which can take into account the dilatancy of soli directly and the related computational model are put forward. The model can calculate the instantaneous and residual pore pressures in sand and depict the liquefaction process of sand quantitatively, …

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 …

Session 3: Discussions And Replies, Multiple Authors

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

No abstract provided.

Dynamic Strength And Permanent Deformation Of Saturated Sand, Masayuki Hyodo, Noriyuki Yasufuku, Hidekazu Murata, Takeharu Konami

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

The undrained cyclic triaxial behavior of saturated sand has been studied using anisotropically consolidated specimens. The strength and deformation under various combinations of initial static and cyclic shear stresses were attempted to clarify. The cyclic strength was first discussed, and then, the residual shear strain was investigated related with effective stress ratio at the end of each stress cycle. Finally, an empirical model was proposed for evaluating the development of pore pressure and residual shear strain of saturated sand subjected to various initial static and subsequent cyclic shear stresses.