Deformation Mechanism of Large-Scale Ancient Reservoir Landslides Driven by the Monitoring Data and Numerical Simulation

Globally, the reactivation of ancient landslides in reservoir areas poses severe threats to the safety of human society and the natural environment, attracting widespread attention in the fields of science and engineering. The periodic reservoir water level fluctuations and precipitation are the main reasons for the reactivation of ancient landslides, and the complexity of landslide disaster prevention and control is expected to increase due to the combined effects of both factors. In this study, a comprehensive method of on-site investigation, displacement monitoring, and numerical simulation has been proposed to analyse the seepage field, stability, and deformation field of the landslide by considering the ancient Qingshi landslide in the Three Gorges Reservoir Area (TGRA) as an example. The numerical simulation method is used to simulate the dynamic evolution process of the Qingshi landslide, and the measured data validates the accuracy of the method. The results indicate that the fluctuations in the reservoir water level and rainfall significantly affect the stability of the Qingshi landslide. The increase in landslide activity is dominated by reservoir water level fluctuations, rather than rainfall. In addition, this study also identifies the potential sliding surface of the landslide and predicts the possible mode of instability. This research can provide technical support and decision-making reference for the early warning and control of landslide disasters in reservoir areas.