Study on the Stability of Accumulated Layer Landslide under the Coupling Action of Earthquake and Rainfall

Tectonic movement, heavy rainfall and other environmental factors are important factors causing the slope instability of accumulation body. Aiming at jiangdingya H1 landslide in Bailong River Basin, Zhouqu County, Gansu Province, the deformation law and stability of accumulation landslide under the coupling condition of earthquake and rainfall were systematically analyzed by means of laboratory physical model test, numerical simulation and theoretical derivation. The results show that: 1) The crack development law of landslide model test under the coupling effect of earthquake and rainfall is analyzed, and the stability characteristics of landslide deformation and failure in three stages are obtained. 2) According to the model test and numerical simulation results, it is found that the coupling effect has the greatest influence on the stability of the slope toe of the accumulation landslide, and the failure mode of the accumulation landslide changes from “pull-shear” failure to “compression-shear” failure, and the failure of the accumulation landslide occurs in a local location. 3) Based on the unbalanced thrust method and GA model, a landslide stability calculation model of loose accumulation body under the coupling effect of earthquake and rainfall was improved by comprehensively considering the effects of complex factors such as seismic inertia force and seepage force. The research results can provide reference for landslide prevention, monitoring and early warning in Zhouqu area of Gansu Province.