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Full-Text Articles in Geotechnical Engineering
Changes Of Yield Stress Of Sand During Undrained Cyclic Loading, Y. Tanaka, K. Shirakawa
Changes Of Yield Stress Of Sand During Undrained Cyclic Loading, Y. Tanaka, K. Shirakawa
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this study, the yield locus of sand being subjected to several cycles of undrained loading was investigated by using the triaxial testing device capable of measuring the acoustic emission, AE, of soil. The AE measurement indicates that the undrained shear on isotropically consolidated sand changes the shape of yield locus so as to have more kinematic hardening type of yield locus. More importantly, a change occurred in the size of yield locus, and the undrained loading has reduced the size of yield locus. Subsequent undrained cyclic loadings further reduced the size of yield locus so that there were some …
Maximum Moduli Of Sands Under Various Loadings, X. J. Zhang, M. S. Aggour
Maximum Moduli Of Sands Under Various Loadings, X. J. Zhang, M. S. Aggour
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Maximum moduli are the primary parameter in the determination of wave velocities in soils. They can be evaluated from either laboratory or field testing. In general, the excitation loadings used in laboratory and field testing are different. The resonant column apparatus was used to study the effect of loading type on the maximum moduli of sands. Sinusoidal, random and impulse loading were used. Sand specimens were tested either longitudinally or torsionally with one of the three types of loading at low strain levels, and the low-amplitude moduli were measured. Maximum moduli of the specimens were obtained from the low-amplitude moduli. …
Verification Of An Elasto-Piastic Earthquake Analysis Procedure, A. Anandarajah
Verification Of An Elasto-Piastic Earthquake Analysis Procedure, A. Anandarajah
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An effective stress based, finite element procedure of modeling earthquake soil and soil-structure interaction problems is described. Elasto-plastic constitutive models are used to describe the stress-strain behavior of soils. A fully-coupled finite element formulation is employed, which allows the pore pressure build-up and dissipation to be modelled simultaneously. Undrained behavior is modelled as a special case of this general formulation. In a previous study, the procedure was used to perform a “before the event” prediction of the liquefaction behavior of a 10-meter thick saturated sand deposit subjected to an earthquake loading. In the present paper, the predictions are compared with …
Dynamic Properties Of A Granular Soil, F. Rodriguez-Roa, G. Palma
Dynamic Properties Of A Granular Soil, F. Rodriguez-Roa, G. Palma
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The variation of the Dynamic Shear Modulus, G, and Damping Ratio, D, in a coarse grained alluvial soil from the Santiago area, Chile, is analyzed when changes occur in its grain size distribution, degree of compaction, confining pressure, magnitude of the cyclic deviator stress, and number of applied loading loops. Using statistical techniques it was possible to determine the degree of influence of each one of such factors in the magnitude of G and D. Further, the experimental error derived from laboratory tests measurements could be evaluated. The Hyperbolic Model shows a better performance than the Ramber-Osgood Model when theoretical …
Static Shear And Liquefaction Potential Of Sand, Chung-Jung Lee
Static Shear And Liquefaction Potential Of Sand, Chung-Jung Lee
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The state parameter, which describes the initial state of sand before shearing, combining with the concepts of critical stress ratio line and phase transform line are used to assess the characteristics of sand during shearing. The state parameter of each tested sample is determined after the steady state line is constructed, and then relations of characteristics of the cyclic deformation behavior and the state parameter of sand are discussed. The value of the lowest point, Sup1 on the CSR line in the p’ – q plot is related to ec for a specific sand. Once the stress path of …
Settlements Of Breakwater On Soft Seabed Ground Under Ocean Waves, J. Zhou, K. Yasuhara
Settlements Of Breakwater On Soft Seabed Ground Under Ocean Waves, J. Zhou, K. Yasuhara
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A procedure for predicting the wave induced excess pore water pressure and residual strain of clay using the results of cyclic triaxial tests on the reconstituted Ariake clay is described. Thereafter, the results of a numerical analysis by a 2-D dynamic effective stress FEM for a breakwater on a soft clay are presented.
Earth Pressure Variations Under Cyclic Surcharges, S. M. Mir Mohammad Hosseini
Earth Pressure Variations Under Cyclic Surcharges, S. M. Mir Mohammad Hosseini
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
There are a tremendous studies in literature about the earth pressure, most of them are concentrated on the static loading conditions. The problems of earth pressure under dynamic loadings are still the case of studies. In this paper the results of an experimental studies about variations of earth pressure at rest under different vertical cyclic loadings are presented. Cubical soil samples of 15 cm dimensions were subjected to vertical cyclic stresses and induced lateral pressure behind the rigid side walls of the soil were measured accurately. A dry and uniform sand was used and the samples were prepared by the …
Effects Of Earthquake Induced Rates Of Shearing On Residual Soil Strength, Achilleas N. Parathiras
Effects Of Earthquake Induced Rates Of Shearing On Residual Soil Strength, Achilleas N. Parathiras
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The behavior of soils when sheared at high rates of displacement, such as those which may be induced by earthquakes, has been investigated by means of the ring shear apparatus. Plastic and non-plastic soils were tested normally and over-consolidated, remoulded and dry, submerged and non-submerged in water, in order to assess the effect which the stress history and the presence of water in the matrix and the environment of the sample have on its response upon fast shearing. It was concluded that two types of behavior exist which depend on the nature of each sample and the presence of water …
Effect Of Fines Content On The Cyclic Undrained Behavior Of Sand, D. Erten, M. H. Maher
Effect Of Fines Content On The Cyclic Undrained Behavior Of Sand, D. Erten, M. H. Maher
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The influence of fines on the liquefaction potential of sandy soils has been studied by conducting isotropically consolidated stress controlled triaxial tests. Experimental results are compared with predictions using the theory developed by Nasser and Shokooh which is based on energy considerations. The theory determines the excess pore water pressure in terms of the number of cycles N, the dimensionless shear stress amplitude, and the initial and minimum values of the void ratio. The comparisons show good agreement between experimental data and model predictions for the pore water generation under cyclic loading for both loose and medium sands and medium …
Static And Dynamic Strength Properties Of A Fiber-Reinforced Compacted Cohesive Soil, R. M. Ai Wahab, G. B. Heckel
Static And Dynamic Strength Properties Of A Fiber-Reinforced Compacted Cohesive Soil, R. M. Ai Wahab, G. B. Heckel
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Soil reinforcement with randomly oriented, individual synthetic fibers has been applied to laboratory specimens of a compacted cohesive soil. Fiber contents of up to 1.0% by soil dry weight were mixed with the soil. Data from unconfined compression (static) testing and resilient modulus (dynamic) testing have been presented. Experimental work showed that the fibers increased the soil unconfined compressive strength, ductility, toughness, static and dynamic energy absorption capacities, the resilient strain and the number of cycles to failure. The soil resilient modulus and the permanent strain both decreased with the increase in fiber content.
Soil Property Determination For A Seismic Study, Kenneth M. Berry, Thomas L. Cooling, Stephen L. Mccaskie
Soil Property Determination For A Seismic Study, Kenneth M. Berry, Thomas L. Cooling, Stephen L. Mccaskie
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Static and dynamic soil property data were needed for input into the seismic retrofit design for the I-155 Mississippi River crossing located near the center of the New Madrid Seismic Zone. Soils consisted of recent river alluvium underlain by very dense soils of the Mississippi embayment. The field investigation consisted of conventional borings, downhole geophysical tests to measure shear wave velocity, and seismic piezo-cone soundings. SPT energy measurements were made at one boring to confirm hammer energy for liquefaction evaluation. This paper summarizes the data and provides site specific correlation of shear wave velocity vs. N-value from the seismic cone …
Modeling Of Volumetric Response Of Cemented Sand Under Cyclic Loading, Krishna R. Reddy
Modeling Of Volumetric Response Of Cemented Sand Under Cyclic Loading, Krishna R. Reddy
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper first describes cyclic tests which were conducted by Iwabuchi (1986) on both uncemented and cemented sands using a true triaxial apparatus. The paper then presents a thermodynamic or endochronic model which was used to predict the volumetric behavior of uncemented and cemented sands under cyclic loading conditions. The predicted results using the thermodynamic model and the test results using the true triaxial apparatus were found to be in good agreement.
Discussions And Replies — Session I, Multiple Authors
Discussions And Replies — Session I, Multiple Authors
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
No abstract provided.
Efficiency Of An Energy-Dissipating Barrier, M. P. Luong
Efficiency Of An Energy-Dissipating Barrier, M. P. Luong
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The proposed paper describes some experimental procedures, used in (a) laboratory to recognize the energy-dissipating ability of soil and (b) in centrifuge to generate in-flight stress waves propagating through a centrifugal soil mass in order to investigate the efficiency of a stress wave mitigation barrier. The screening principle of this new type of energy-dissipating barrier has been suggested by the dissipative behavior of sandy soils, evidenced by infrared vibrothermography.
Soil-Pile-Structure During Liquefaction On Centrifuge, Masayoshi Sato, Yasuhiro Shamoto, Jian-Min Zhang
Soil-Pile-Structure During Liquefaction On Centrifuge, Masayoshi Sato, Yasuhiro Shamoto, Jian-Min Zhang
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Larger scale dynamic centrifuge modeling has been used to examine the behavior of a soilpile-structure system during earthquake-induced liquefaction. The model consisting of a 3 x 3-pile supported structure and a saturated sand deposit was constructed in a laminar container with the inside dimensions of 74-cm length, 50-cm height and 34-cm width. Test results show that liquefaction occurred only within a finite zone in the saturated sand deposit subjected to a strong input shaking that corresponds to a maximum earthquake acceleration of 0.3 g induced probably in actual ground, which agrees well with the results of earthquake damage investigation; moreover, …
Centrifuge Modeling Of A Tilting Wall With Liquefiable Backfill, N.-H. Ting, R. V. Whitman
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 …
Earthquake Input Motions For Physical Model Tests, Gregg L. Fiegel, I. M. Ldriss, Bruce L. Kutter
Earthquake Input Motions For Physical Model Tests, Gregg L. Fiegel, I. M. Ldriss, Bruce L. Kutter
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The results from several dynamic centrifuge experiments are presented in this paper; the experiments were performed as part of a study to assess the influence of local site conditions on earthquake ground motions. Medium dense dry sand and saturated soft clay models were subjected to the accelerogram recorded at Santa Cruz during the 1989 Loma Prieta Earthquake. Scaled versions of the input motion were used to shake the soil models; in addition, different time steps were used in order to study the effects of frequency content of the input motion. The results confirm that the characteristics of the input motion …
Preliminary Investigation Of A Buried Pipe Excited By An Earthquake, Hubert K. Law, Hon-Yim Ko, Jun Tohda, Liming Li, Takeshi Hamada
Preliminary Investigation Of A Buried Pipe Excited By An Earthquake, Hubert K. Law, Hon-Yim Ko, Jun Tohda, Liming Li, Takeshi Hamada
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The consequence of a devastating earthquake is usually a result of fires, which are caused by breakage of gas pipelines and lack of water supply from damaged water pipelines. The seismic response of a buried pipe was studied using the geotechnical centrifuge facility at the University of Colorado, Boulder. Ottawa sand labeled F-75 was used to model the ground, which was contaminated in a rigid container with inside dimensions of 48 in. long, 12 in. wide and 9 in. deep. A 4-foot long micro PVC pipe having a 1/4-inch-inside diameter and a 5/16-inch-outsIde diameter was used to model a prototype …
The Uplift Capacity Of Anchors Embedded In Loose Sand, Adam F. Bolt, Eugeniusz Dembicki
The Uplift Capacity Of Anchors Embedded In Loose Sand, Adam F. Bolt, Eugeniusz Dembicki
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The results of scale model tests of uplift capacity of shallow and deep anchors in loose fully saturated sands are presented. The anchors were subjected to static, cyclic and post cyclic loading. The parameters tested included the effects of embedment ratio, anchor shape, relative soil density, amplitude and number of cycles, and post cyclic response to loading. The factors influencing the behavior of the anchors are discussed.
Critical Acceleration Levels For Free Standing Bridge Abutments, K. L. Fishman, R. Richards Jr., R. C. Divito
Critical Acceleration Levels For Free Standing Bridge Abutments, K. L. Fishman, R. Richards Jr., R. C. Divito
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An analytic procedure for predicting threshold accelerations for movement of gravity wall bridge abutments due to earthquake loading is described. The method draws on previous work related to the sliding mode of failure, and a newly developed theory on seismic reduction of bearing capacity. The main contribution of this paper is to present laboratory observations verifying mode of failure and critical acceleration levels predicted by this procedure for model retaining wall bridge abutments subjected to seismic excitation on a shaking table. Three different test series were performed with different interface conditions between the wall, and the bridge deck, soil foundation, …
Behaviour Of Saturated Sand Models Under Principal Stress Axes Rotation In Shake Table Tests, Eiji Yanagisawa, Fardin Jafarzadeh
Behaviour Of Saturated Sand Models Under Principal Stress Axes Rotation In Shake Table Tests, Eiji Yanagisawa, Fardin Jafarzadeh
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
One dimensional shake table tests were performed on saturated loose or medium dense Toyoura sand models, in order to study the response of level grounds during earthquakes and the nature of generated excess pore water pressure. 12 virgin models which prepared under identical condition, were subjected to cyclic and three different irregular shear stress patterns. It is shown that there is correlation between excess pore pressure ratio and developed shear strain, independent from applied shear stress histories and density of the models. Also, the relations of accumulated shear work as well as normalized shear work, per unit volume, are considered …
Dynamic Deformation Characteristics Of Rockfill Materials From Laboratory Test, In-Situ Test And Earthquake Motion Analysis, Tomoya Lwashita, Nario Yasuda, Akira Nakamura, Osamu Takeda
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.
Numerical Modelling Of Shear Wave Propagation In Centrifuge Models, S. P. Gopal Madabhushi
Numerical Modelling Of Shear Wave Propagation In Centrifuge Models, S. P. Gopal Madabhushi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Shear modulus of a soil layer increases with the effective confining stress. This results in a reduction in the propagation velocity of shear waves as they travel from the bed rock towards the soil surface. In a centrifuge model prototype stresses and strains are recreated at homologous points. Thus the effective confining stress and hence the shear modulus will vary with depth in a centrifuge model. This results in a change in the propagation velocity of the shear waves as they travel from the base of the container towards the soil surface. This change in the propagation velocity was investigated …
Microconcrete Subjected To Static And Dynamic Compression Loadings, Bassam Hwaija
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.
Permanent Displacements And Tilting Angle Of Small Footings On Sand, H. V. P. Truong, P. J. Moore
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.
Factors Affecting Vibration Induced Settlement, D. S. Kim, S. Drabkin
Factors Affecting Vibration Induced Settlement, D. S. Kim, S. Drabkin
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In urbanized areas, vibration induced settlement on granular soils depends on vibration characteristics including vibration path and source, in-situ stress conditions, and soil properties. Quantitative laboratory assessment of settlement was extrapolated using parametric study of in-situ settlement of sands. It is shown that vibration amplitude should be monitored within the vulnerable soil layers or evaluated considering attenuation characteristics of soil. Combining the effects of influencing factors, the discussed model can be utilized to predict vibration induced settlement of structures on sand.
Dynamic Centrifuge Experiment On A Cantilever Retaining Wall, M. M. Dewoolkar, A. T. Stadler, S. N. Batiste, H. Y. Ko, R. Y. S. Pak
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 …
Cycle Plate Load Tests On Reinforced Sand, Swami Saran, B. V. K. Lavania, R. K. Sharma
Cycle Plate Load Tests On Reinforced Sand, Swami Saran, B. V. K. Lavania, R. K. Sharma
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper presents a set of results of laboratory scale model footing tests conducted to determine the cyclic load resistance of sand beds reinforced with horizontal sheets of geogrid. The test results indicate that the total settlement decreases and the bearing capacity increases, with the increase in size of reinforcements and number of layers. With the inclusion of reinforcing sheets, ·the coefficient of elastic uniform compression decreases slightly; but this decreased value is valid up to the increased bearing capacity of the reinforced sand bed. There is significant improvement in the damping capacity upon reinforcing the sand bed as indicated …
KOd Apparatus, Type Tk-1, Longgen Zhu, Lizhi Xu, Jian Du
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.
Dynamic Loading Induced Settlement Of Strip Foundation On Geogrid-Reinforced Clay, Braja M. Das, Eun C. Shin, Bang-Woong Shin, Bong-Jik Lee, Ki-Taek Jung
Dynamic Loading Induced Settlement Of Strip Foundation On Geogrid-Reinforced Clay, Braja M. Das, Eun C. Shin, Bang-Woong Shin, Bong-Jik Lee, Ki-Taek Jung
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Laboratory model tests to determine the load. The variation of the maximum permanent supported by geogrid-reinforced saturated clay and subjected to a low-frequency cyclic load are presented. In conducting the test, the foundation was initially subjected to an allowable static load. The cyclic load was then super-imposed over the static permanent settlement of a surface strip foundation settlement with the intensity of the static load and the intensity of the amplitude of the cyclic load are also presented.