LIQUEFACTION CHARACTERISTICS OF UNDISTURBED AND REMOLDED SAMPLES WITH THE SAME DENSITY AND SHEAR WAVE VELOCITY

Abstract

 In order to investigate the liquefaction characteristics of undisturbed and remolded samples which have the same specimen density and shear wave velocity, a series of undrained cyclic triaxial tests was performed. The high quality undisturbed samples were collected from alluvial sandy layer in Chiba City by Gel-Push sampling method. The remolded samples were prepared by dry tamping and wet tamping method to adjust the specimen densities at the same level as that of the undisturbed sample. The shear wave velocity, measured by trigger and accelerometer method during isotropic consolidation, of the remolded samples was confirmed to be almost the same as that of the undisturbed sample. The test results show that even though the same specimen density and shear wave velocity, the liquefaction resistance and the behavior during cyclic loading were different between the undisturbed samples and the remolded samples. The reasons for the difference may be caused by a cementation effect acting on the soil fabric by aging and/or an inherent anisotropy of the specimens.