基于DEM方法的滑坡堰塞坝几何特征分析

Geometric Characteristics Analysis of Landslide Dam Based on the Discrete Element Method

基于离散元法(DEM)对滑坡堰塞坝的几何特征进行了数值模拟,考虑沟道断面形态、滑坡速度以及沟床坡度三种因素的影响,共27种组合。结果表明:沟道断面形态、滑坡速度对堰塞坝横向、纵向几何形态都有影响,而沟床坡度只对堰塞坝纵向几何特征产生影响;滑坡速度增大,堰塞坝纵剖面顶宽和底宽的比值减小,堰塞坝的有效厚度减小;沟床坡度增大,堰塞坝下游坝坡内角减小,上游坝坡内角增大,两者的比值减小,堰塞坝坝坡倾角的变化规律与内角的变化规律相反。

By using Discrete Element Method (DEM), numerical simulations on the geometric characteristics of landslide dams were investigated with the concern of three factors of the cross section of valley, valley inclination and landslide speed. Those factors made up 27 cases in total. The results of DEM simulations indicate that the cross section of valley and landslide speed have influences on the geometric characteristics of dams in both transverse and longitudinal directions;while the valley inclination only has influence on the longitudinal direction. With the increasing of landslide speed, the ratio of top width of dam profile to the bottom width decreases and the effective thickness of dam profile decreases as well. With the increasing of valley inclination, the ratio of dam inner slope in downstream to the dam inner slope in upstream decreases, however, the surface slope of dam changes in the opposite direction.