To investigate the influencesof non-plastic silt and soil aging on the re-liquefaction resistance of sands,a series of undrained triaxial tests was performed on sand-silt mixtures with finescontent ranging from 0%to 1...To investigate the influencesof non-plastic silt and soil aging on the re-liquefaction resistance of sands,a series of undrained triaxial tests was performed on sand-silt mixtures with finescontent ranging from 0%to 100%,as well as on undisturbed and reconstituted non-plastic sandy soils retrieved from earth structures with a history of earthquake-induced damage.The specimens on sand-silt mixtures were produced under an initial degree of compaction of 95%.In these tests,liquefaction histories were applied three times to a single specimen under the same cyclic stress ratio after the respective consolidation stages with the measurements of the shear wave velocities.The following conclusions can be obtained from the test results:(1)The liquefaction resistance obtained in the firstto third cyclicloading stages decreased initially with increasing finescontent up to about 45%,while it increased afterward.Therefore,the susceptibility of sands containing a relatively large amount of non-plastic silt to reliquefaction may be more significantthan that of clean sands;(2)The liquefaction resistance and the shear wave velocity decreased significantlyduring the second cyclic-loading stage and after the second consolidation,respectively,despite an increase in the specimen density caused by the first liquefaction history,while they increased in the third stage.The possible reason for this change would be the disturbance of soil structures due to liquefaction,which may be partially evaluated by the volumetric strain during the respective consolidation stages,and the stress-induced anisotropy formed in the previous liquefaction stage;and(3)The liquefaction resistance and the shear wave velocity of the undisturbed specimens,which were measured in the firstto third stages,were larger than those of the reconstituted ones due to the aging effects,respectively.That is,the aging effects may not necessarily be eliminated by the subsequent liquefaction history and may remain partially in some cases.展开更多
基金supported by JSPS KAKENHI(Grant Nos.JP22K04305 and JP19K15083).
文摘To investigate the influencesof non-plastic silt and soil aging on the re-liquefaction resistance of sands,a series of undrained triaxial tests was performed on sand-silt mixtures with finescontent ranging from 0%to 100%,as well as on undisturbed and reconstituted non-plastic sandy soils retrieved from earth structures with a history of earthquake-induced damage.The specimens on sand-silt mixtures were produced under an initial degree of compaction of 95%.In these tests,liquefaction histories were applied three times to a single specimen under the same cyclic stress ratio after the respective consolidation stages with the measurements of the shear wave velocities.The following conclusions can be obtained from the test results:(1)The liquefaction resistance obtained in the firstto third cyclicloading stages decreased initially with increasing finescontent up to about 45%,while it increased afterward.Therefore,the susceptibility of sands containing a relatively large amount of non-plastic silt to reliquefaction may be more significantthan that of clean sands;(2)The liquefaction resistance and the shear wave velocity decreased significantlyduring the second cyclic-loading stage and after the second consolidation,respectively,despite an increase in the specimen density caused by the first liquefaction history,while they increased in the third stage.The possible reason for this change would be the disturbance of soil structures due to liquefaction,which may be partially evaluated by the volumetric strain during the respective consolidation stages,and the stress-induced anisotropy formed in the previous liquefaction stage;and(3)The liquefaction resistance and the shear wave velocity of the undisturbed specimens,which were measured in the firstto third stages,were larger than those of the reconstituted ones due to the aging effects,respectively.That is,the aging effects may not necessarily be eliminated by the subsequent liquefaction history and may remain partially in some cases.
