Degradation Behavior of Normally Consolidated Clay Under Cyclic Loading Condition

The degradation behavior of soil may become important when considering the response of soft clay under cyclic loading condition. A nonlinear model was proposed by Idriss, et al. to account for the degradation behavior based on the controlled-strain test. By adopting a numerical procedure, the data obtained in controlled-stress cyclic triaxial test can be used to find the degradation parameter defined in the nonlinear degradation model proposed by Idriss, et al. A series of consolidated-undrained controlled-stress and controlled-strain cyclic triaxial tests were performed on laboratory manufactured normally consolidated soft clay samples. The relationship between degradation parameter and strain was determined based on data of controlled stress test with the numerical procedure. The resulting values of degradation parameter versus strain from both controlled-stress test and controlled-strain test were compared