Research Progress of Unsaturated Strongly Weathered Sericite Schist Residual Soil

The settlement and deformation of soft rock are the main problems hindering the construction of tunnel engineering. The use of soft rock and its residual soil has become the focus of engineering development at home and abroad. Sericite schist is an extremely soft rock, and most of the sericite schist residual soil in nature is in an unsaturated state. The Baishitou Tunnel of Dali-Lincang Railway is located in Yun County, Lincang City, Yunnan Province. The surrounding rock in the tunnel is mainly soft rock, such as sericite schist and carbonaceous schist. Due to the action of the earthquake, the rock mass is easily broken and its strength is low, making construction extremely difficult. Strongly weathered sericite schist has the characteristics of soft rock, easy to weather, and the rock mass is relatively easy to break. Its residual soil has similar properties to its parent rock and is often encountered in actual engineering. The research on unsaturated strongly weathered sericite schist and its residual soil has become the focus of research by scholars at home and abroad. The engineering properties of unsaturated soils have become one of the main research directions of soil mechanics.