A Research On Instability Of Landslide Under Earthquake Using DDA

In recent years,landslides caused by earthquake and other disasters have occurred frequently,which has led many scholars in related fields to focus on the related research of landslides.This paper focuses on the failure of landslide caused by seismic waves.Due to the large cost of shaking table test,the discontinuous deformation analysis method is considered to dynamically shows the whole process of collapse of landslides,and observes the track of the movement of the landslide and other important physical quantities,hoping to find out the laws related to the characteristics of the movement.The main contents of this paper are as follows:(1)This paper introduces the characteristics of discontinuous deformation analysis method and the calculation process of the whole DDA Systematically.A GUI is developed for the initial DDA program by using MATLAB.which simplifies the using process of DDA program.(2)Referring to related papers,three commonly used methods of seismic loading are put forward:loading the time history of acceleration to sliding block,loading the time history of volume force to base,and loading the time history of displacement curve to base.In this paper,a ideal model of block sliding from the slope under the simple harmonic wave is proposed,and the theoretical formula of relevant physical quantities is derived.Various physical quantities are monitored by DDA and compared with the analytical solution,and the better loading method is selected.After selecting the loading method,the Donghekou landslide is simulated to exclude other irrelevant factors.(3)Taking an actual dangerous rock zone of Heye hotel in Jiuzhaigou as a model,considering the influence of density,height.volume coefficient.peak intensity of simple harmonic waves and vertical and horizonal simple harmonic wave on rock collapse process,monitoring the relevant physical quantities and recording the track of the movement,and analyzing the relevant laws.It is found that the final horizontal displacement of rockfall has obvious positive correlation with the height and the peak acceleration of horizontal harmonic loading.but not with the size and density of dangerous rock and the peak velocity of rockfall has obvious positive correlation with the density of dangerous rock,the peak acceleration of earthquake and the height of rockfall.but not with the size of dangerous rock(4)DDA method is used to simulate the shaking table test of landslide with two sets of parallel joints to verify the influence of the angle of slope,the angle of two sets of joints,cohesion and friction angles on the final displacement of collapse process,and to record the final shape of landslides.It is found that the smaller the friction angle is,the farther the horizonal distance is when the friction angle of anti-joint and bedding joint is changed simultaneously;when the angle of anti-joint is changed separately,the sliding distance firstly decreases and then increases with the increase of friction angle.