BEHAVIOR OF SOFT SOILS UNDER UNDRAINED CYCLIC LOADING WITH INITIAL SHEAR STRESS

摘要

Four series of undrained cyclic triaxial tests have been conducted on undisturbed soft soils to investigate the effect of initial shear strength and deformation of silty clay and clays. The test results suggest that the silty clay is relatively stable than the clays for a cyclic loading. The cyclic shear strength has a reasonable relation with the plasticity index of soils. A simple relation among the normalized plots of peak pore pressure u_p/u_f the loading cycle N/N_f, and the peak axial strain ε_(pa), is introduced. The predictions show good agreement with the observed test results. Post cyclic reconsolidation behavior after undrained cyclic loading is found to be independent of cyclic shear stress and initial shear levels. This study provides a basis for evaluating the undrained cyclic response of soft foundation, due to cyclic loadings such as in earthquake and storm wave action.