Experimental investigation and strength prediction model for thixotropy of saturated marine soft clay

The thixotropy of marine soft clay is of great significance for the design and construction of offshore wind power projects. In this paper, the thixotropic properties of marine soft clay with different water contents are analyzed by the unconfined compressive strength test and vane shear test. The test results demonstrate that: (1) The shear strength of the undisturbed soft clay is significantly higher than that of the disturbed soft clay, indicating that the marine soft clay is a highly sensitive soil with strong inherent structure. (2) After disturbance of remolded marine soft clay, the higher the water content, the lower the shear strength. (3) The shear strength of marine soft clay gradually recovers with the resting time, and the strength recovery rate is significantly proportional to the water content. Based on test data, a modified empirical model is employed to evaluate the thixotropic recovery ratio and strength recovery process of disturbed marine soft clay. The model parameters are obtained by regression analysis, and the fitting effect of the model is good. Therefore, this study can provide better predictions for the estimation of the shear strength of disturbed soft clay in offshore wind power engineering projects.