Abstract: To investigate the shear mechanical behavior at the siltcemented soil interface, a series of interface shear tests were conducted using a self-developed large-scale interface shear apparatus. The effects of multiple factors on the shear mechanical properties of the silt-cemented soil interface were analyzed. The results show that the interface shear stress-displacement relationship exhibits an elasto-plastic trend, but no residual stage appears when the silt is saturated. During interface shearing, the silt displays dilatancy, which becomes more pronounced under higher normal stress; increased interface roughness enhances dilatancy when the silt has a relatively low water content. Increasing normal stress, increasing interface roughness, and decreasing water content all contribute to higher interface shear strength. The interface shear failure conforms to the Mohr-Coulomb criterion. The study also clarifies the relationship between peak and residual interface shear strength under unsaturated conditions. These findings provide a useful reference for analyzing the stress and deformation behavior of cement-soil structures embedded in silt in practical engineering.

Key words: Silt-Cement Soil Interface, Interface Shear Test, Normal Stress, Interface Roughness, Moisture Content