One-Dimensional Consolidation of Visco-Elastic Marine Clay Under Depth-Varying and Time-Dependent Load

Abstract

There is a lack of generalized solution for analyzing consolidation of visco-elastic clay subjected to an increase in total stress under various time-dependent loading conditions. In this paper, a generalized Voigt model is used to simulate various visco-elastic properties of marine clay to a high degree of accuracy. The increase in total stress in clay is assumed to be a function of both depth and the time of loading. Instantaneous loading, ramp loading, triangular and rectangular cyclic loading conditions are considered. Analytical solutions to calculate the degree of consolidation are derived by using the method of separation of variables and the Laplace transform. Their validity and accuracy are verified by comparing the special cases of the proposed solutions with available analytical solutions. The distribution pattern of the increase in total stress as a function of depth, as well as the viscosity coefficients of clay, is shown to have an important influence on the consolidation behavior. Moreover, the degree of consolidation under cyclic loading conditions oscillates up and down during each cycle of loading and unloading. The range of variation of the degree of consolidation increases with increasing number of cycles, and it reaches an asymptotic value when t→∞.