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Centrifuge Modeling Of A Tilting Wall With Liquefiable Backfill, N.-H. Ting, R. V. Whitman Apr 1995

Centrifuge Modeling Of A Tilting Wall With Liquefiable Backfill, N.-H. Ting, R. V. Whitman

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

A series of dynamic centrifuge tests was carried out to simulate the seismic behaviors of an idealized model retaining wall and the liquefiable backfill supported by the wall. The wall is hinged at the base and is supported near the top by an anchor with finite strength. Eighteen tests with various peak accelerations were applied to six saturated sand models prepared at two relative densities and with two pore fluid viscosities. Permanent tilt in the wall as a result of temporary failure of the anchor occurred in some tests. Results from tests without anchor failures were used to form a …

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Dynamic Deformation Characteristics Of Rockfill Materials From Laboratory Test, In-Situ Test And Earthquake Motion Analysis, Tomoya Lwashita, Nario Yasuda, Akira Nakamura, Osamu Takeda Apr 1995

Dynamic Deformation Characteristics Of Rockfill Materials From Laboratory Test, In-Situ Test And Earthquake Motion Analysis, Tomoya Lwashita, Nario Yasuda, Akira Nakamura, Osamu Takeda

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

On dynamic analyses of rockfill dams, dynamic deformation characteristics of rockfill materials such as shear moduli and damping ratios must be known to make analysis more accurate. In this study, large-scale cyclic triaxial tests were carried out using rockfill materials of actual dams, and the results were compared with the dynamic deformation characteristics obtained by in-situ geophysical explorations and response analyses of earthquake motions observed at dams. Furthermore, the radiation damping ratio was estimated from response analyses and laboratory tests, and then the frequency and strain dependency characteristics of the radiation damping were evaluated.

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Microconcrete Subjected To Static And Dynamic Compression Loadings, Bassam Hwaija Apr 1995

Microconcrete Subjected To Static And Dynamic Compression Loadings, Bassam Hwaija

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

The object of our paper is to consider the influence of the particularly important factor, and to achieve a model describing the behavior of the microconcrete. The specimens have been loaded in rates ranging from 0.0001 to 800 (1/s). The results are discussed available in the literature.

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Permanent Displacements And Tilting Angle Of Small Footings On Sand, H. V. P. Truong, P. J. Moore Apr 1995

Permanent Displacements And Tilting Angle Of Small Footings On Sand, H. V. P. Truong, P. J. Moore

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

This paper presents the comparison between the proposed theoretical prediction and experimental results of horizontal and vertical permanent displacements, and tilting angle of small rigid square and rectangular footings on relatively uniform sand. Old and new lumped parameters for different modes of vibrations, i.e. horizontal, vertical and rocking vibrations are used in the analysis. Some good agreement is found between the theory with the new lumped parameters and experiments, but the relevant dynamic soil properties are still the most critical parameters that need to be measured. Finally, effects of frequency and rocking heights are also investigated.

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Dynamic Centrifuge Experiment On A Cantilever Retaining Wall, M. M. Dewoolkar, A. T. Stadler, S. N. Batiste, H. Y. Ko, R. Y. S. Pak Apr 1995

Dynamic Centrifuge Experiment On A Cantilever Retaining Wall, M. M. Dewoolkar, A. T. Stadler, S. N. Batiste, H. Y. Ko, R. Y. S. Pak

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

Seismic loads on a tall, cantilever retaining wall were studied using centrifuge modeling. An aluminum wall (55' prototype) retaining dry, cohesionless backfill was subjected to two successive dynamic events. The backfill surface was horizontal and even with the top of the wall. The input motion was supplied via a servo-controlled, electro-hydraulic shake table. The input motion was roughly sinusoidal with peak horizontal accelerations of approximately 0.2g and 0.4g for the first and second dynamic events, respectively. The input motion frequency was 1 hz at prototype scale. Lateral earth pressures on the wall, wall displacement, and accelerations of the wall and …

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KOd Apparatus, Type Tk-1, Longgen Zhu, Lizhi Xu, Jian Du Apr 1995

KOd Apparatus, Type Tk-1, Longgen Zhu, Lizhi Xu, Jian Du

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

The lateral pressure coefficient Kod of soil under the cyclic load is an important parameter in designing structures against wave, earthquake, and wind. The Lateral Pressure Coefficient Apparatus, Type TK-1 under the cyclic load, written in the simplified form of Kod Apparatus, Type TK-1, is especially developed to study and determine Kod. Its structure, specifications and test results have shown that this apparatus has superior performances, met the requirements to study and determine Kod.

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Application Of Deep Compaction Techniques To Liquefaction Prevention, G. Armijo, P. Sola, C. Oteo Apr 1995

Application Of Deep Compaction Techniques To Liquefaction Prevention, G. Armijo, P. Sola, C. Oteo

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

This article analyzes the application of dynamic compaction, vibroflotation and vibroreplacement (stone columns) to liquefaction prevention. The ground types to which they can be applied, the depths that can be reached and the degree of improvement that can be obtained are all studied. Finally, and on the basis of the above, basic guidelines are given for the design of ground improvement with these techniques and for the aforementioned purpose.

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North Morecambe Terminal, Barrow, Ground Stabilisation And Pile Foundations, C. A. Raison, B. C. Slocombe, A. L. Bell, J. I. Baez Apr 1995

North Morecambe Terminal, Barrow, Ground Stabilisation And Pile Foundations, C. A. Raison, B. C. Slocombe, A. L. Bell, J. I. Baez

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

Very poor ground conditions and soils that were susceptible to liquefaction to depths of up to 20m beneath the site were major problems for the construction of the largest natural gas processing terminal in Europe. An innovative foundation solution combining deep vibro compaction with short cast in place piles driven into the treated soils was adopted as both cost and programme effective. The Design and Build project also included advance civils work comprising earthworks, drainage and road construction. The contract started in September 1991 and was completed by October 1992, with the process plant programmed to be on-stream by October …

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A Simple Model For Pore Pressure Build-Up Of Soil Under Dynamic Loadings, J. H. Hwang, C. H. Chen Apr 1995

A Simple Model For Pore Pressure Build-Up Of Soil Under Dynamic Loadings, J. H. Hwang, C. H. Chen

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

A simple pore pressure build-up model is introduced in this paper to simulate the effective-stress paths of saturated soils subjected to dynamic loadings. It is a five-parameter model in which two pairs of two parameters are used to define the effective-stress paths during the loading phases of first cycle and post-phase-transformations, respectively, and a dynamic pore pressure parameter is judiciously introduced to represent the increment of pore pressure due to shear loading in between the previous two phases. All parameters can be easily deduced from conventional undrained triaxial tests. Satisfactory results have been achieved for case studies including published results …

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Liquefaction During The 1991 April 22 Telire-Limon Earthquake And Correlations With The Methods Of Seed And Iwasaki, Per Hafström, Jan Skogsberg, Anders Bodare Apr 1995

Liquefaction During The 1991 April 22 Telire-Limon Earthquake And Correlations With The Methods Of Seed And Iwasaki, Per Hafström, Jan Skogsberg, Anders Bodare

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

Sites within the area affected by liquefaction due to the 22 April 1991 Limón-Telire earthquake, have been investigated in order to compare the results of some empirical methods with the incidents observed during the earthquake. The purpose of this comparison was to suggest a suitable method to be used when assessing the risk for liquefaction in Costa Rica in the future.

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A Procedure To Assess The Stability Of Buried Structures Against Liquefaction-Induced Ground Deformations, M. Satoh, M. Hamada, R. Isoyama, A. Hatakeyama Apr 1995

A Procedure To Assess The Stability Of Buried Structures Against Liquefaction-Induced Ground Deformations, M. Satoh, M. Hamada, R. Isoyama, A. Hatakeyama

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

First, an empirical formula to predict the magnitude of permanent ground displacement is proposed based on the observed data at the past earthquake events. Next, a simplified procedure to estimate the failure probability of buried pipes is proposed, in which the model of non-linear beam supported by ground spring elements is used to calculate the strain in the pipe by following the response displacement method. Finally, a simplified method to obtain the probability considering failure modes expected to occur in the pipe is proposed and some numerical example showing the probability and discussions follow.

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Seismic Safety Retrofit Of Second Narrows Bridge Foundations Geotechnical Design Aspects, U. D. Atukorafa, D. Wijawlckl'ema, T. P. Fltzell, N. R. Mccammon Apr 1995

Seismic Safety Retrofit Of Second Narrows Bridge Foundations Geotechnical Design Aspects, U. D. Atukorafa, D. Wijawlckl'ema, T. P. Fltzell, N. R. Mccammon

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

The geotechnical engineering analyses carried out for the seismic safety retrofit design of Second Narrows Bridge located in Vancouver, Canada, are presented. The work involved detailed ground response analyses to evaluate the liquefaction potential of site soils, the development of a series of numerical models to assess the pattern and magnitude of liquefaction-induced ground displacements, and to analytically evaluate the ground displacements with potential ground improvements.

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Liquefaction Case Study Of Volcanic Gravel Layer During 1993 Hokkaido-Nansei-Oki Earthquake, T. Kokusho, Y. Tanaka, K. Kudo, T. Kawai Apr 1995

Liquefaction Case Study Of Volcanic Gravel Layer During 1993 Hokkaido-Nansei-Oki Earthquake, T. Kokusho, Y. Tanaka, K. Kudo, T. Kawai

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

During the Hokkaido-Nansei-Oki Earthquake, a high-land area around the foot of the volcano, Mt. Komagatake, in Hokkaido in Northern Japan experienced liquefaction phenomena inflicting damages of differential settlement in some tens of houses in the area. Several kinds of geotechnical site investigations were carried out to study the cause of the damage in a typical liquefaction site. Trenching and geological survey disclosed that Holocene debris avalanche deposit containing a plenty of large rocks actually liquefied. The undrained cyclic triaxial test was carried out on large intact samples taken out by the in-situ freezing sampling. The stress ratio measured in the …

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Shaking Table Tests On Transient Flow Of Liquefied Ground, I. Towhata, H. Toyota Apr 1995

Shaking Table Tests On Transient Flow Of Liquefied Ground, I. Towhata, H. Toyota

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

An attempt was made to predict the time history of the lateral displacement of ground that liquefied due to earthquakes. The study was initiated by model tests to examine the nature of liquefied sand. The knowledge thus obtained was combined with the theory of Lagrangean equation of motion in order to develop a method of prediction. Comparison was then made between prediction and observation.

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Correlation Between Cpt Data And Dynamic Properties Of In Situ Frozen Samples, Y. Suzuki, K. Tokimatsu, Y. Taya, Y. Kubota Apr 1995

Correlation Between Cpt Data And Dynamic Properties Of In Situ Frozen Samples, Y. Suzuki, K. Tokimatsu, Y. Taya, Y. Kubota

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

Correlations between cone penetration resistance and liquefaction resistance of sandy soils are examined, based on high quality undisturbed samples obtained by the in situ freezing method. For this purpose, the CPT tests are conducted at six sites where in situ frozen sands with fines contents up to 30 % were sampled and their dynamic properties were determined in the laboratory. The comparison of the CPT data with the soil properties of the in situ frozen samples has shown that: (1) Robertson's soil classification chart performs well for sandy soils in Japan; (2) the CPT qt-value shows a good correlation with …

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The Liquefaction Of Sand Lenses Due To Cyclic Loading, J. D. Holchin, L. E. Vallejo Apr 1995

The Liquefaction Of Sand Lenses Due To Cyclic Loading, J. D. Holchin, L. E. Vallejo

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

Many studies have been conducted on the effects of cyclic loading on homogeneous saturated deposits of sand, and to a lesser extent on silt and clay. In contrast, very little research has been performed on the effects of cyclic loading on saturated sand lenses located within clay masses. Sand lenses and thin discontinuous layers of loose sand are frequently encountered in saturated clay or silt deposits located in areas of the United States prone to earthquakes. Sand lenses are also frequently associated with hydraulic fill structures, which are known to perform poorly during earthquake loading. The liquefaction and failure of …

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Generalized Plasticity And Cyclic Pressuremeter Test Modelling, A. Saïtta, J. Canou, L. Dormieux Apr 1995

Generalized Plasticity And Cyclic Pressuremeter Test Modelling, A. Saïtta, J. Canou, L. Dormieux

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

A constitutive model based on generalized elastoplasticity (Zienkiewicz et al., 1985) is used for the modelling of monotonic and cyclic pressuremeter tests in a clay. The permeability of the material is taken into account for the modelling of the excess pore water pressure generation during the test (combination of pore pressure build up and dissipation). It is shown how this type of model can simply represent the main features observed during a cyclic pressuremeter test in a clay, particularly the accumulation of excess pore water pressure during the cycles of loading, and the importance of dissipation on the excess pore …

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Liquefaction Of The Alluvial Soils Of Bangladesh, M. A. Mollah Apr 1995

Liquefaction Of The Alluvial Soils Of Bangladesh, M. A. Mollah

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

In this paper, the potential of the often-saturated sandy soils that occur within the uppermost sub-surface stratigraphy across the Bangladesh plains to experience initial liquefaction due to seismically induced pore water pressure is evaluated. Bore hole logs from development projects were collected. Standard Penetration Test (SPT) values from the drill holes were utilized as the primary data and a widely practiced computational method was employed to estimate the liquefaction potential. The analysis of data indicated that the uppermost portion of the sandy soil layer within 20 m of the surface is loose and sensitive to liquefaction under the influence of …

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Prediction Of Settlements Of Soft Clay Caused By Earthquakes, Zhou Jian, K. Yasuhara Apr 1995

Prediction Of Settlements Of Soft Clay Caused By Earthquakes, Zhou Jian, K. Yasuhara

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

This paper develops an analytical method for the calculation of the earthquake-induced settlement of foundation by using Biot's type consolidation equation. In order to investigate the effectiveness of the proposed method, a comparison of the numerical result with the observed earthquake-induced settlement on the site at Sendai in Japan caused by the miyagioki earthquake in 1987 will be presented.

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Effective Stress Liquefaction Analysis At The Wildlife Site, P. M. Byrne, J. Mcintyre Apr 1995

Effective Stress Liquefaction Analysis At The Wildlife Site, P. M. Byrne, J. Mcintyre

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

An incremental stress-strain model for granular soils based on fundamental soil mechanics principles is presented. The model captures the drained skeleton behavior observed in laboratory tests under cyclic loading. The undrained behavior is captured using the same skeleton stress-strain relation together with the volumetric constraint imposed by the pore water fluid. The model predicts cyclic simple shear response in close agreement with observed cyclic test data in terms of pore water pressure rise, cycles to trigger liquefaction, as well as the characteristic post-liquefaction response. Finally, the model is incorporated in a dynamic analyses procedure and applied to the field case …

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Determination Of Liquefaction Potential Using Dielectric Concept, A. Kaya, H. Y. Fang Apr 1995

Determination Of Liquefaction Potential Using Dielectric Concept, A. Kaya, H. Y. Fang

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

In this paper existing insitu test methods to determine possible liquefaction potential of a site are discussed briefly with their advantages and limitations. Then, resistivity method is presented and showed how both resistivity and dielectric constant can be coped to determine insitu properties of soils such as cementation factor and porosity without disturbing the soil structure by means of Time Domain Reflectometry (TDR). A procedure is also presented to obtain both resistivity and dielectric constant of granular soils in the field. It is concluded that the proposed method and procedure is superior to the existing methods.

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Discussions And Replies — Session Iii, Multiple Authors Apr 1995

Discussions And Replies — Session Iii, Multiple Authors

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

No abstract provided.

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Lateral Stress Ratio On Retaining Structures After Earthquake Loading, Constantine A. Stamatopoulos Apr 1995

Lateral Stress Ratio On Retaining Structures After Earthquake Loading, Constantine A. Stamatopoulos

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

Equations are derived by analysis g1vmg the earthquake-induced change in the permanent horizontal stress acting on frictionless vertical walls retaining dry sand. These equations exhibit a limit in the coefficient of lateral pressure that depends only on the slope of the critical state line and the Poisson's Ratio of the backfill. The horizontal stress after dynamic shaking increases or decreases towards this limit. Predictions agree qualitatively with results of laboratory tests.

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Earthquake Induced Displacement Of Gravity Retaining Walls, X. Zeng Apr 1995

Earthquake Induced Displacement Of Gravity Retaining Walls, X. Zeng

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

Centrifuge tests were conducted to study the displacement of gravity retaining walls during earthquakes. Theoretical analysis based on Newmark's sliding block method was used to analyze the data. For a gravity wall with dry backfill, sliding block method generates reasonable results. However, the method is difficult to apply for a retaining wall with saturated backfill. Comprehensive numerical methods need to be used. A method of calculating the tilting of gravity walls is introduced.

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On Seismic Design Displacements Of Rigid Retaining Walls, Shamsher Prakash, Yingwei Wu, Eyjolfur Ami Rafnsson Apr 1995

On Seismic Design Displacements Of Rigid Retaining Walls, Shamsher Prakash, Yingwei Wu, Eyjolfur Ami Rafnsson

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

Correlation of the dynamic displacement and significant factors are presented. Three computer programs (Rafnsson, 1991) have been modified to develop design charts. The wall dimension computed by static condition and related displacement under dynamic loading can be estimated from the computer programs. Twenty-one combinations of base soil and back fill, 5 different ground motions and 7 different heights of wall are used in the analyses to develop design charts. These will help the designer to predict the dynamic behavior of retaining walls and to optimize the design work. Furthermore, equations have been fitted to predict the displacement without using the …

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Discussions And Replies — Session Iv, Multiple Authors Apr 1995

Discussions And Replies — Session Iv, Multiple Authors

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

No abstract provided.

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Soil Investigation And Fvt Analysis In Hualien Lsst Ssi Research, T. Ueshima, K. Kudo, T. Kokusho, T. Okamoto, Y. Tanaka Apr 1995

Soil Investigation And Fvt Analysis In Hualien Lsst Ssi Research, T. Ueshima, K. Kudo, T. Kokusho, T. Okamoto, Y. Tanaka

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

An international joint research program, Large-Scale Seismic Test (LSST) Program at Hualien, Taiwan, is ongoing, where a large-scale model structure partly embedded in gravelly layer was constructed, in-depth site soil geotechnical investigation was performed at every one of four construction stages, that is, before excavation, after excavation before structure construction, after structure construction before backfill, and after backfill, forced vibration tests (FVTs) of the model structure before backfill (FVT-1) and after backfill (FVT-2) were performed, and seismic observation of the dynamic SSI (soil-structure interaction) system is underway. This paper describes the change of the shear wave velocity (Vs) accompanied by …

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Effect Of Soil Dilatancy On Vibration And Earth Pressure, Y. Ohshima, H. Watanabe Apr 1995

Effect Of Soil Dilatancy On Vibration And Earth Pressure, Y. Ohshima, H. Watanabe

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

A model ground of air dried sand compacted in a shear testing apparatus and two composite models each of which have the model pit of different rigidity buried in a same model ground as above one are excited horizontally with sinusoidal motions on a shaking table. From measured accelerations and dynamic earth pressure it is found that the vertical vibration is produced in the ground due to the dilatancy or volume change of soil and yet it produces the dynamic earth pressure acting horizontally on all outside walls of the model pit. In order to simulate the results of tests …

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Improved Soil-Spring Method For Soil-Structure Interaction — Vertical Excitation, A. H. Hadjian, H. T. Tang Apr 1995

Improved Soil-Spring Method For Soil-Structure Interaction — Vertical Excitation, A. H. Hadjian, H. T. Tang

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

An improved Soil-Spring Method for vertical response analysis is proposed. The Soil-Spring Method belongs to the sub structuring methods of analyses for seismic soil-structure interaction. As originally developed the method has certain significant limitations. The proposed improvement is essentially iterative where, successively, layering, embedment, soil damping and frequency-dependent effects are introduced and adjusted until acceptable convergence is achieved. Additionally, input motion for embedded structures is specified using a simple procedure. The methodology is applied to the Lotung 1/4-scale containment model for three recorded earthquakes. The comparisons of the response results with the recorded data and with results obtained using state-of-the-art …

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Foundation Soil Influence On The Seismic Response Of Piers, P. P. Diotallevi, R. Poluzzi Apr 1995

Foundation Soil Influence On The Seismic Response Of Piers, P. P. Diotallevi, R. Poluzzi

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

Significant experimental dynamic tests by vibrodyne were conducted on single piers of a motorway near Livomo (Italy). Tests were conducted on structures similar to each other but founded on two different type of soils (under consolidated silts below the water table and over consolidated clays) and very different dynamic responses were found in terms of damping and natural frequencies. This effect was particularly evident for single piles proving the importance of soil characteristics upon the dynamic response of the structure. It is refere also a numerical investigation about the behavior of identical structures founded on different soils and subjected to …

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