MODELING OF STRESS-STRAIN BEHAVIOR OF SOFT CLAY UNDER CYCLIC LOADING

摘要

Iwan models often used in modeling the non-linear and hysteretic behavior of soils under cyclic loading conditions, are unreliable when there is significant cyclic degradation and residual strain accumulating of the stress-stain curves, Especially, for soils with initial shear stress which the cumulative residual strain increase significantly, Iwan models often fail to simulate. In the present paper, the stiffness reduction and residual strain accumulating behavior of Hangzhou soft clay with different initial static shear stresses under stress-controlled undrained cyclic triaxial conditions are researched. Based on the test results, empirical models for cyclic degradation and residual strain accumulating are proposed. The empirical models are further incorporated into Iwan model to simulate the cyclic stress-strain relationship of soft clay. A comparison between experimental and predicted stress-strain curves shows good agreement.