基于3DEC模拟的既有铁路单体滑坡危险性分区与评价——以川黔线裁缝岩滑坡为例

The Hazard Division and Evaluation of Single Landslide Based on 3 Dimension Distinct Element Simulation of the Existing Chuan-Qian Railway

为了快速、准确地对既有铁路单体滑坡开展危险性分区与评价,将3DEC数值模拟和层次分析法(AHP)相结合,并利用"触发因素重现周期信息"的方法,制作川黔线裁缝岩滑坡危险性分区图,确定滑坡的年失稳概率。研究表明,该滑坡再次失稳后,滑坡前缘将滑入綦江中,形成体积约14×104m3的滑坡坝,并且有约723 m3溜滑体滑至川黔铁路雷吼洞洞口,阻塞铁路;该滑坡再次失稳的3日累计降雨量阈值为78. 7 mm,年失稳概率为56%。相较于传统方法,该方法可定量判别单体滑坡失稳后的运动路径和影响范围,为铁路应急抢险和后期防灾减灾提供指导和帮助。

In order to quickly and accurately divide and evaluate the hazard of single landslide along the existing railways,3 DEC numerical simulation and analytic hierarchy process( AHP) were combined,furthermore the method of "reproducing periodic information of trigger factors"was used to prepare the hazard division map of Caifengyan landslide on Chuan-Qian railway,and the annual probability of stability loss of the landslide was determined. The results indicate that the slip mass will slide into Qijiang river after the landslide failure again to form a landslide dam of about 14×104 m3,and another slip mass of about 723 m3 will slide into Leihou Portal of the Chuan-Qian railway to cause a block on the route. Besides,the three-day cumulative precipitation threshold causing failure of the landslide is confirmed as 78. 7 mm and annual probability of stability loss of the landslide is 56%. Compared with the traditional one,this method can be used to quantitatively identify the movement path and influence range after the single landslide instability,providing guidance and help for railway emergency rescue and disaster prevention and reduction in the later period.