Influence of Dry-Wet Cycles on the Structure and Shear Strength of Loess

The dry-wet cycle is an important factor that causes slope instability and foundation settlement in loess regions. In order to study the effects of the dry-wet cycle on the structure and shear strength of loess, isotropic compression tests and triaxial shear tests were carried out on loess with different numbers of dry-wet cycles. The results show that the dry-wet cycles mainly reduce the cohesion of loess, and the most obvious decline is after the first cycle; however, they have no effect on the angle of internal friction of loess. The structural yield strength and structural parameters of loess can represent the structure of loess well, which gradually decrease with the increase in the number dry-wet cycles and water content. The initial yield surface is approximately an ellipse, which gradually shrinks with the increase in water content and dry-wet cycles. The structure and cohesion of loess have similar changes, and there is an obvious exponential function relationship between them.