Post-cyclic degradation of saturated plasticity silts

摘要

The results from post-cyclic triaxial tests on saturated silty soils have shown that the post-cyclic degradation in stiffness is more marked that of undrained strength, thus increasing the possibility of post-earthquake deformation and settlements. The normalized post-cyclic stiffness is influenced by the initial soil particle structures produced during sample preparation and decreases with increasing initial static shear stress and overconsolidation ratio. These are therefore important factors influencing post-cyclic degradation in stiffness. Post-cyclic undrained strength normalized by the undrained strength prior to cyclic loading is less influenced by these three factors. Post-cyclic degradation in strength and stiffness for normally consolidated and over-consolidated plastic silt can be formulated as a function of the normalized excess pore pressure.