基于离散元Runout预测的张家湾滑坡风险评估

QUANTITATIVE EVALUATION OF LANDSLIDE RISK IN ZHANGJIAWAN BASED ON DISCRETE ELEMENT RUNOUT PREDICTION

滑坡是我国最重要的地质灾害之一,其每年造成大量的人员伤亡和财产损失,故滑坡风险评估对防治滑坡灾害、降低社会经济损失具有重要意义。基于现场野外调查,利用离散元软件UDEC对西宁市张家湾滑坡进行Runout预测分析,结合动力分析与条件分析法对张家湾滑坡进行风险评估。结果表明:张家湾滑坡在天然工况下为稳定状态,在暴雨工况下为欠稳定状态,其最远移距为55m,最大影响范围为1.106×105 m2;张家湾滑坡在暴雨工况下的失稳概率为0.459;张家湾滑坡一旦在暴雨情况下发生失稳,人员伤亡风险值为46人,根据滑坡灾害社会接受水平曲线判定其属于不可接受范围;经济损失风险值为5180.88万元。根据经济损失风险等级进行判断其属于第5等级。

Landslide is one of the most important geological disasters in China,which causes a large number of casualties and property losses every year,so landslide risk assessment is of great significance to prevent and control landslide disasters and reduce social and economic losses.Based on field investigation,Runout prediction analysis of Zhangjiawan landslide in Xining City is carried out by using discrete element software UDEC,and the risk assessment of Zhangjiawan landslide is carried out by combining dynamic analysis and conditional analysis.The results show that the Zhangjiawan landslide is basically stable under natural conditions and understable under heavy rain conditions,with the maximum displacement of 55 m and the maximum influence range of 1.106×10^(5) m^(2).The instability probability of Zhangjiawan landslide under rainstorm condition is 0.459.Once Zhangjiawan landslide is unstable under heavy rain,the risk value of casualties is 46 people,and according to the curve of social acceptance level of landslide disaster,it belongs to the unacceptable range.The risk value of economic loss was 51.8088 million yuan.According to the risk level of economic loss,it belongs to level 5.