天然和暴雨条件下的物质点滑坡变形机制分析

Analysis of deformation mechanism of landslide under natural and rainstorm conditions based on material point method

摘要:

为准确评估边坡失稳后对滑动路径上建筑物及人们生命财产的威胁程度，本文以郴州某滑坡为例，利用物质点法，分别模拟了天然和暴雨两种工况下该边坡在开挖后的大变形破坏机制，并计算了其滑动距离，并将结果与传统有限元分析进行了对比。结果表明：（1）开挖前，该边坡在天然工况下处于基本稳定状态，在暴雨工况下处于失稳状态，而开挖后，该边坡在两种工况下都处于失稳状态；（2）开挖后该滑坡的滑动距离显著增大，在天然工况和暴雨工况下的滑动距离分别为20.11和24.12 m；（3）对比稳定性分析和大变形分析结果可知，开挖和降雨是该边坡失稳的两种主要因素，计算边坡失稳后的滑动距离可为评估其对滑动路径上建筑物的威胁程度提供理论参考，对提高边坡安全性防护有重要意义。

关键词:边坡失稳;大变形分析;物质点法;滑坡;滑动距离

Abstract:

In order to accurately evaluate the threat to buildings and people’s lives and properties in the run-out path after slope failure， this paper takes a landslide in Chenzhou as an example， simulates the failure mechanism of large deformation under natural and rainstorm conditions after excavation of this slope based on the material point method， calculates the run-out distance， and compares the results with the finite element method. The results show that： （1） Before excavation， the slope is basically stable under natural condition and unstable under rainstorm condition， while after excavation， the slope is unstable under both conditions； （2） The sliding distance of the landslide increases significantly after excavation， and the sliding distance under natural conditions and rainstorm conditions is 20.11 and 24.12m respectively； （3） By comparing the results of stability and large deformation analysis， it can be seen that excavation and rainfall are the two main factors causing slope instability. Calculating the sliding distance after slope instability can provide theoretical reference for evaluating the threat to buildings on the sliding path， and is of great significance for improving slope safety protection.

Key words:slope instability;large deformation analysis;material point method;landslide;sliding distance