Probability analysis of submarine landslides based on the Response Surface Method: A case study from the South China Sea

As deep-sea engineering develops, it becomes essential to analyze the stability of submarine slopes when considering the stability of submarine foundations or evaluating the safety of offshore structures. However, the traditional method for analyzing slope stability does not give adequate consideration to the uncertainty of soil properties, and so the reliability method has been proposed and used to settle the variation of soil parameters. Regarding the northern slope of the South China Sea, the present paper summarizes its geomorphic features, seismic characteristics, and the soil strength at certain boreholes. A typical slope section is chosen with which to conduct probability analysis using the polynomial-based Response Surface Method (RSM) and the Advanced First Order Second Moment method(AFOSM). A novel form of the RSM based on Gaussian Process Regression (GPR) is also proposed and applied in this case to approximate the limit state function, and its efficiency is confirmed. The simulation results of Latin-hypercube analysis are set as the benchmark for the other methods. The influences of slope gradient and seismic action on the stability of submarine slopes are also investigated.