Experimental Research on the Deformation and Failure Characteristics of Coarse-Grained Soil Slopes in Seasonal Frozen Region along Sichuan-Tibet Railway

The field investigation of the seasonal coarse grained frozen soil slopes along the eastern section of the proposed Sichuan-Tibet railway shows that the deformation and failure of the slopes are widespread. In order to explore the deformation characteristics and failure mechanisms of the slopes in this area and provide a basis for the design and protection of the slopes along Sichuan-Tibet railway, laboratory model tests on the seasonal coarse grained frozen soil slopes under snowfall conditions were conducted. The results show that, the deformation and failure of the seasonal coarse grained frozen soil slope are caused by the repeated alternation of the failure of the surface soil structure caused by frost heave and the surface soil saturation caused by snow thaw infiltration, and the reduction of the shear strength of the surface soil under repeated freezing and thawing conditions. The deformation and failure of the seasonal coarse grained frozen soil slopes along the eastern section of the Sichuan-Tibet railway are mainly characterized by creep-flowed, topsoil slip and slippage on slope surface. The emphasis of slope protection in this area are slope thermal insulation and waterproof.