NFLUENCE OF FRAGMENTATION ON DYNAMIC CHARACTERISTICS OF LOESS LANDSLIDE BASED ON DEM SIMULATION

A fragmentable discrete element landslide model takes into account the unique structure of loess and is built on the basis of PFC^2D in order to investigate the impact of slide fragmentation on the dynamics of loess landslides. The landslide occurrence process under various fragmentation rates is simulated. The impact of fragmentation on the landslide velocity,mobility,and accumulation features is examined in order to replicate the whole process of the Dangchuan 8-meter landslide from beginning to end. The results show the follows. (1)The peak velocity of the slide is inversely related to the fragmentation rate,as evidenced by the fact that the maximum velocity of the slide movement falls as a power function with an increase in fragmentation rate. (2)There could be a cutoff point for the fragmentation-based encouragement of landslide mobility,below which the effective friction coefficient rapidly declines and does not change appreciably when the fragmentation rate rises above it. (3)As the degree of fragmentation increases,the landslide accumulation thickness decreases,sorting decreases,the horizontal dispersion broadens,the distribution of pores becomes more homogeneous,and the highest accumulation thickness is frequently found in low-lying terrain. (4)The Dangchuan 8-meter landslide had a fragmentation rate of 19%,a maximum local velocity of around 17 m·s^-1,a maximum sliding distance of roughly 195 m,and a total duration from destabilization to cease movement of 28 s. It demonstrates how fragmentation affects a landslide's dynamic process,providing some useful context for those looking into the subject.