Strength Recovery Model of Clay during Thixotropy

Abstract

Thixotropy is a hot topic in the field of rheology of dispersed systems. Many researchers have proposed different models and hypotheses to explain the thixotropy of clay. In this paper, the strength recovery model of Zhanjiang Formation clay in the process of thixotropy is studied. Firstly, through unconfined compressive strength test, the influence of soil sensitivity, moisture content, and density on the strength growth of remolded soil was studied. The results show great influence of sensitivity, moisture content, and density on the thixotropic strength of the Zhanjiang Formation clay: the higher the sensitivity and the density, the stronger the thixotropy of soil; the higher the moisture content, the weaker the thixotropy of soil. Based on the test results, a strength recovery model of Zhanjiang Formation clay in the process of thixotropy was established. The model was verified by the validation test data and the data obtained from the existing literature. The results suggest that the model prediction is in good agreement with the verification test data and data from existing literature, which proves the confidence of the model in predicting the degree of strength recovery in the process of thixotropy of Zhanjiang Formation clay. The model provides basis for stability calculation of surrounding soil after construction disturbance of underground structures in this stratum.

Unconfined compressive strength and pore structure evolution law of structural clay after disturbance

“…Clay thixotropy of refers to a phenomenon in which the original soil structure is destructed when the soil is disturbed, and its mechanical strength decreases dramatically. After disturbance, part of the mechanical strength gradually recovers with time (Boswell, 1948;Skemption and Northey, 1952;Mitchell, 1961;Mewis, 1979;Barnes, 1997;Díaz-Rodríguez and Santamarina, 1999;Tang et al, 2021a). and studied the change rule of mechanical properties of reconstituted clays with specific water content over time, finding that the shear strength and yield stress of reconstituted clays increased significantly after 90 d compared to the initial moment.…”

Large-Strain Consolidation Analysis Accounting for Time-Dependent Effects in Clayey Tailings and Soft Soils

“…According to their findings, the preconsolidation pressure increases linearly with the logarithm of time. Tang et al (2021) introduced an empirical equation to estimate the strength gain of reconstituted natural clays over time considering aging effects. The equation takes into consideration factors such as water content, sensitivity, and the strength of undisturbed soil.…”