Mechanism of continuous movement and long-term safety analysis of Baitieba landslide based on field monitoring data and numerical simulation

Baitieba landslide, located on the left bank of Xiluodu reservoir, is an ancient landslide. The landslide slides along the shallow and deep sliding surfaces after excavation. Sliding along the shallow sliding surface has become stabilised by and large; whereas sliding along the deep sliding surface still continues after some effective and systematic treatments. Based on the data of inclinometer boreholes observed in the field, a detailed investigation into the mechanism of continuous sliding along the deep sliding surface is carried out. It is found that slow creep of the ancient sliding zone is a predominant factor, and its creep deformation has undergone two stages: attenuation of creep deformation and linear increase of creep deformation. A numerical simulation, considering creep behaviour of the ancient slip zone, is also conducted to verify the mechanism of movement of the landslide inferred from the monitoring data of inclinometer boreholes. Using the monitoring data, long-term stability of the landslide is analysed and it is concluded that the landslide is stable overall.