Run-out characteristic simulation of a surcharge-induced soil landslide using the material point method

Spoil ground surcharge is one of the main factors inducing landslides in hilly grounds triggered by human engineering activities. The material point method (MPM) belongs to one of the meshless numerical analysis method, which can effectively simulate the material behavior and the run-out characteristics of landslides. Based on the discrete method using the linear shape function, the MUSL solving format and the Drucker-Prager yield criterion, we develop a single-layer and single-phase MPM model to simulate the run-out process of landslides. In comparison with the benchmark experiment results of the process of a sand pile losing its stability and simulated with accumulated dry aluminum bars, the proposed MPM model is verified. The run-out process of the typical scenario of the surcharged-induced soil landslide is simulated using MPM. The related results during the representative moments of the run-out process, including the morphology of slope mass, the plastic strain distribution and sliding velocity evolution trends of reference points, are obtained. The results of the numerical example show that the surcharge-induced soil landslide belongs to the thrust-type landslide, and is of the progressive failure. The whole run-out process can be divided into 4 stages, namely, the slope crest compression, local creep sliding, accelerated sliding and decelerated sliding. Concerning the sliding front, the results of parametric analysis also show that a strong positive correlation property exists between both of the kinetic representative parameters and the surcharge amount, and a strong negative correlation property exits between the kinetic representative parameters and the cohesion or internal friction angle of the soil. It is noted that the kinetic representative parameters include the maximal sliding acceleration, velocity, distance and kinetic energy of the slope mass. Based on 29 typical scenarios, the linear regression equations of all of the above 4 kinetic representative parameters, denoted by the surcharge amount, cohesion and internal friction angel of the soil, are established to predict the disastrous behavior of the surcharge-induced soil landslides.