Effects of frequency and CSR on dynamic properties of marine clay in drained condition

This paper presents an experimental investigation of the effects of frequency and cyclic stress ratio (CSR) on soil dynamic properties in terms of three parameters (k, εp, and S) obtained from hysteresis loops under cyclic loading in drained conditions. A series of dynamic loading tests were carried out on Lianyungang marine clay samples with a sinusoidal wave at various values of frequency and CSR. Results showed that both frequency and CSR had significant effects on the three parameters. A rapid decrease in dynamic stiffness (related to k) and then a slow decrease with the increasing number of cycles characterized the overall dynamic response of soil under dynamic loading with various frequencies and CSRs, while the residual plastic strain (related to εp) and the energy dissipation capacity (related to S) increased rapidly at a relatively lower number of cycles. The higher the frequency, the greater is the k at a given time. The higher the CSR, the lower is the k at a certain number of cycles. The higher the frequency, the lower is the εp or S at a given time. The higher the CSR, the greater is the εp or S at a certain number of cycles.