四川宝轮服务区降雨型滑坡活动过程分析

Analysis on process of rainfall-induced landslide in Baolun service area,Sichuan Province

特殊的顺倾层状坡体结构、不合理的坡脚人工开挖与罕见的强降雨的共同作用,是公路、铁路沿线降雨型滑坡灾害发生的重要原因。宝轮服务区属于降雨型滑坡,除具备上述条件外,还存在相对隔水、遇水极易软化成为滑床的炭质泥岩层。本文基于兰州至海口高速公路服务区滑坡坡体地形地貌、地层岩性、水文地质特征和区域气候条件,采用FLAC^3D软件模拟计算并分析了天然与饱水状态下边坡坡体的变形,验证了宝轮服务区特殊顺层坡体不合理坡脚人工开挖与罕见强降雨型滑坡诱发机理,计算表明与滑坡变形特征有着较强的一致性,同时具有很高的可信度;提出了宝轮服务区特殊顺层坡体不合理坡脚人工开挖与罕见强降雨降雨型滑坡形成过程及其特征,对类似滑坡防治具有重要的指导价值。

The combination of special bedding slope structure,unreasonable artificial excavation at the foot of the slope with the unusual heavy rainfall is an important reason for the occurrence of rainfall-induced landslide along highway and railway.Baolun service area is located in the rainfall-type landslide zone.In addition to the above conditions,there are also carbonaceous mudstone layers that are relatively impermeable to water and easily soften into sliding beds.In this paper,based on the topographic,geomorphic,stratigraphic,hydrogeological characteristics and regional climatic conditions of the landslide slope in the service area of Lanzhou to Haikou Expressway,FLAC^3D software was used to simulate and analyze the deformation of the slope body below the natural and full water state.It also verified induced mechanism of irrational slope foot excavation and rare heavy rainfall landslide in special bedding slope body in Baolun service area.The results show that it is consistent with the deformation characteristics of the landside and has a high degree of credibility.This paper puts forward the process and characteristics of unreasonable slope foot artificial excavation and rare heavy rainfall rainfall type landslide in the special bedding slope body in Baolun service area,which has important guiding value for the prevention and control of similar landslide.