Strength Characteristics of Ili Loess and Its Landslide Numerical Simulation

The loess landslide has seriously affected the construction and safe operation of highway engineering. Based on indoor experiments, theoretical derivation, and numerical simulation, the strength characteristics of the Ili Naba Highway H1 landslide, as well as the stability and failure mode of the landslide, were systematically analysed. The results show that: (1) The relationship between residual strength and shear displacement of Ili loess can be mainly divided into three stages: the rapid growth stage before peak, the strain softening stage, and the residual strength stage. An increase in soil water content will reduce the residual strength of Ili loess; (2) Under radial fracturing, the main failure modes of Ili loess include brittle fracturing and plastic fracturing. There is no significant difference in tensile strength between remoulded and undisturbed loess samples. The cohesion of loess samples is one of the main sources of tensile strength. (3) Under the condition of single physical field of solid mechanics, H1 landslide has good stability, and the failure mode is tension shear composite failure. Under the coupled conditions of seepage stress, the H1 landslide is in an unstable state on the 4th day of rainfall, with the main failure mode being shear failure at the foot of the slope.