Applying the strength reduction method to study of stability of residual mountains: A particular application

Due to huge disaster-caused force, seismic geological disasters primarily induce residual landslide, collapse and debris flow disasters with far higher hazard extent than that of earthquake disasters. Wherefore, this paper, with various vibration slopes caused by the most representative Wenchuan earthquake as research objects, introduces the strength reduction method to the stability study of residual mountains in a certain area, puts forward dynamic stability slope evaluation method based on dynamic and overall strength reduction method to obtain the mountain slope stability situation in the process of gradual instability, searches out the sliding surface of progressive expansion making use of dynamic strength reduction method and calculates dynamic safety index in the process of gradual slope instability pursuant to the calculation advantages of dynamic strength reduction method, so as to realize the analysis and regulation of the whole process of slope instability. The results show that in the stability analysis of a homogeneous slope, the safety index of slope stability calculated by strength reduction method is 6.7%, 8.8% and 10.5% higher than that calculated by finite element limit equilibrium method, Bishop method and Janbu method respectively. In the stability analysis of a multi-layer soil slope, the safety index of slope stability calculated by strength reduction method is 4.8%, 4.3% and 9.4% higher than that calculated by other three algorithms. While in the stability analysis of soft interlining slope, the safety indexes of slope stability calculated by the method proposed in this paper are increased by 26.10%, 29.11% and 26.46% respectively compared with other three algorithms, indicating that the stability of landslide residual mountains calculated by strength reduction method proposed in this paper is the highest.