The seismic loading on saturated soil deposits induces a decrease in effective stress and a rearrangement of the soil-particle structure, which may both lead to a degradation in undrained stiffness and strength of soi...The seismic loading on saturated soil deposits induces a decrease in effective stress and a rearrangement of the soil-particle structure, which may both lead to a degradation in undrained stiffness and strength of soils. Only the effective stress influence on small strain shear modulus Gmax is considered in seismic response analysis nowadays, and the cyclic shearing induced fabric changes of the soil-particle structure are neglected. In this paper, undrained cyclic triaxial tests were conducted on saturated sands with the shear wave velocity measured by bender element, to study the influences of seismic loading on Gmax. And Gmax of samples without cyclic loading effects was also investigated for comparison. The test results indicated that Gmax under cyclic loading effects is lower than that without such effects at the same effective stress, and also well correlated with the effective stress variation. Hence it is necessary to reinvestigate the determination of Gmax in seismic response analysis carefully to predict the ground responses during earthquake more reasonably.展开更多
The main reason for earthquake-induced landslides is liquefaction of soil,a process considered to occur mostly in sandy soils.Liquefaction which occurs in clayey soils has also been reported and proven in the recent l...The main reason for earthquake-induced landslides is liquefaction of soil,a process considered to occur mostly in sandy soils.Liquefaction which occurs in clayey soils has also been reported and proven in the recent liters- ture,but liquefaction in clayey soils still remains unclear and there are many questions that need to be addressed.In order to address these questions,an depth study on the liquefaction potential of clayey soils was conducted on the ba- sis of field investigation and a series of laboratory tests on the samples collected from the sliding surface of the land- slides.The liquefaction potential of the'soils was studied by means of undrained cyclic ring-shear tests.Research re- sults show that the liquefaction potential of sandy soils is higher than that of clayey soils given the same void ratio; the soil resistance to liquefaction rises with an increase in plasticity for clayey soils;relation between plasticity index and the liquefaction potential of soil can be used in practical application to estimate the liquefaction potential of展开更多
基金Project supported by the National Natural Science Foundation ofChina (No. 10372089) and Provincial Department of EducationZhejiang Province (No. 20010572) China
文摘The seismic loading on saturated soil deposits induces a decrease in effective stress and a rearrangement of the soil-particle structure, which may both lead to a degradation in undrained stiffness and strength of soils. Only the effective stress influence on small strain shear modulus Gmax is considered in seismic response analysis nowadays, and the cyclic shearing induced fabric changes of the soil-particle structure are neglected. In this paper, undrained cyclic triaxial tests were conducted on saturated sands with the shear wave velocity measured by bender element, to study the influences of seismic loading on Gmax. And Gmax of samples without cyclic loading effects was also investigated for comparison. The test results indicated that Gmax under cyclic loading effects is lower than that without such effects at the same effective stress, and also well correlated with the effective stress variation. Hence it is necessary to reinvestigate the determination of Gmax in seismic response analysis carefully to predict the ground responses during earthquake more reasonably.
文摘The main reason for earthquake-induced landslides is liquefaction of soil,a process considered to occur mostly in sandy soils.Liquefaction which occurs in clayey soils has also been reported and proven in the recent liters- ture,but liquefaction in clayey soils still remains unclear and there are many questions that need to be addressed.In order to address these questions,an depth study on the liquefaction potential of clayey soils was conducted on the ba- sis of field investigation and a series of laboratory tests on the samples collected from the sliding surface of the land- slides.The liquefaction potential of the'soils was studied by means of undrained cyclic ring-shear tests.Research re- sults show that the liquefaction potential of sandy soils is higher than that of clayey soils given the same void ratio; the soil resistance to liquefaction rises with an increase in plasticity for clayey soils;relation between plasticity index and the liquefaction potential of soil can be used in practical application to estimate the liquefaction potential of
