Abstract: Thixotropy is a research hotspot in the rheology of dispersion systems. Clay thixotropy is an extraordinary phenomenon of clay, which shows that the strength of clay decreases after being disturbed, and the strength recovers gradually after standing. To discuss the influences of clay content, water content, void ratio, and sensitivity on the thixotropy of clay, we designed orthogonal test on Zhanjiang Formation structural clay with strong, medium, and weak sensitivities to implement unconfined compressive strength tests with different curing ages. The experimental results show that: in terms of the thixotropic strength of clay, there are power function relationships between clay content, moisture content, void ratio, and thixotropic strength of clay, and it decreases as the values of these three parameters increase. There is a logarithmic relationship between sensitivity and the thixotropic strength of clay, and it increases with the increase of sensitivity. For the above four parameters, R² is greater than 0.95, which has a good correlation. In terms of the thixotropic strength ratio of clay, it increases with increasing the clay content, water content, and sensitivity, and decreases as the void ratio increases. In addition, for samples with the same sensitivity, the void ratio has the greatest impact on thixotropy, followed by water content, and finally clay particle content. Finally, we used the least squares method to perform multiple regression fitting and developed a multiple regression prediction model for the relationship between the factors and the intensity of thixotropy.

Key words: Zhanjiang Formation structural clays, thixotropy, orthogonal test, multiple regression