Study on the Failure Mechanism, Safety Grading and Rainfall Threshold of Landslide Caused by Typhoon Rainstorm

Typhoon rainstorms have induced massive landslides in the southeast coastal areas of China, causing serious property losses and casualties. Based on field rainfall data during various typhoons in Fujian Province of China, finite element modelling is carried out to simulate the safety state of slope subjected to typhoon rainstorm. Considering the coupling effect of seepage field and stress field, the transient variation characteristics of seepage field and the equivalent slope plastic zone are revealed. Based on the grading of safety factor, the slope safety state is divided into four grades. Numerical results indicate that rainfall intensity, total rainfall and rainfall duration have great impact on the slope safety. This study is expected to provide some reference value for the early safety warning and emergency management of slopes under extreme conditions such as typhoon rainstorm.