天水市大沟滑坡-泥石流运动过程模拟分析

滑坡-泥石流通常由降雨触发，是一种危害极大的灾害链。本文以甘肃天水市大沟村泥岩滑坡-泥石流为例，从滑坡后壁取原状泥岩样进行固结不排水（CU）三轴剪切试验，获取强度参数，利用LS_RAPID软件对该滑坡-泥石流运动过程进行模拟，再现了滑坡从发生到转化为泥石流的过程。试验表明饱和泥岩的摩擦角仅11，小于沟道坡度。模拟表明滑坡下滑至坡脚时滑体平均速度为5.2ms-1，对沟道滑床具有极大的冲击作用，滑床泥岩在滑坡强大的冲击作用下强度进一步降低，有利于滑坡体迅速转化为泥石流，并造成更大的致灾范围，模拟堆积范围和形态与实测基本一致。

ANALYSIS AND SIMULATION OF THE LANDSLIDE-DEBRIS FLOW HAZARD IN DAGOU VILLAGE,TIANSHUI CITY

Landslide-debris flow usually triggered by heavy rainfall is a kind of great hazard chain. This paper takes the landslide-debris flow which is located at the southern Dagou Village of Mapaoquan Town, Tianshui City, Gansu Province as an example. In order to get the physical parameters needed in the simulation, 4 groups of mudstone samples were taken from the lateral sliding surface of landslide area to conduct consolidated undrained(CU)triaxial tests and some conventional laboratory tests. The above experiments show that the friction angle of saturated mudstone is 11nd is smaller than that of channel slope. Based on the experimental results, we utilized LS-RAPID which is a simulation software system to simulate the movement process of the landslide-debris flow. The simulation results show that the landslide sliding average speed is 5.2ms-1 when it moved to toe of slope. The landslide was converted into debris flow under the powerful impact in the sliding process of landslide, then caused larger disaster area. Accumulation range and shape of simulation and actual measurement are the similar.