Numerical Simulation Study Of Landslide Hazards Using Seismic Signal Analysis

There are four catastrophic rockslide-debris avalanches occurred in Nayong,Guizhou on August 28,2017,Wulong,Chongqing on June 5,2009,Maoxian,Sichuan on June 24,2017,Shuicheng,Guizhou on July 23,2019 respectively.Based on field investigation,remote sensing images,seismic signal and numerical simulation,the runout behavior of these four rockslidedebris avalanches was analyzed.Main research work and achievements of this paper are as follows:(1)With the long-period seismic signals,the nonlinear regression model was established to identify the location of the rock avalance.(2)Based on intensity of ground motion and time-frequency analysis of seismic signals,the duration of each stage of the landslide movement process was analyzed qualitatively.(3)We obtained the force-time function of the landslide by inverting long-period seismic signals and then calculated kinetic parameters of the sliding mass from the inverted force-time function.The results indicated that the movement process of the debris flow can be divided into initial breaking stage,impacting-spreading stage and slow braking stage quantitatively.(4)Spatial partitioning of the debris flow was obtained according to the remote sensing and images before and after the event.In order to study the dynamic characteristics of Nayong rockslide-debris avalanche,a three dimensional numerical model built by the satellite imagery was used to simulate this event.Based on the kinetic parameters calculated from the inverted force-time function,numerical simulations were conducted through and Mat DEM.The velocity distribution,variation of the energy,heat energy distribution,movement distance and velocity of monitored particles and some other dynamic characteristics were obtained.The results illustrate that Mat DEM can simulate the generation,variation and distribution of the energy and the micro-motion properties of particles in the movement process of the debris flow.