四川省宣汉县樊哙镇滑坡的基本特征及形成机制分析

2009年7月16日21时30分,宣汉县樊哙镇古凤村大风滩发生了严重的滑坡灾害,其滑坡方量约50×104m3,最大滑移距离达40m,约10×104m3滑体物质进入河床,将约80m宽的河道堵塞过半(约40m)。滑坡造成民房垮塌和相关设施的毁坏,经济损失巨大。在对滑坡区的地质条件、降水特征等综合分析的基础上,本文根据滑坡形成的过程探讨了滑坡发育特征及形成机制。分析表明,该滑坡是暴雨造成前河河水水位上涨冲刷滑坡前缘所致,超强降雨起到了冲刷、顶托、楔裂、促动的作用。既存在有利于滑坡形成的地质地貌条件,又有不合理的人为活动的因素。深入研究樊哙镇古风村滑坡的形成条件和成灾机理,对该区地质灾害的预防与治理提供一定的技术支持,进而对我国西南地区存在与大风滩滑坡类似的临河型滑坡的灾害隐患点的减灾防灾工作也具有一定的借鉴意义。

Analysis on the Basic Characteristics and Formation Mechanism of Gufeng Village Landslide in Fankuai Town, Xuanhan County, Sichuan Province

At 21：30 p.m.of the 16th in July,2009,the slide has been taken place in the Dafengtan of Gufeng village of Fankuai town of Xuanhan the volume of slide is about 50×104 m3,the maximum sliding distance is 40m,and about 10×104m3 sliding body substances run into the river to bloke more than half of the river（about 40m）,sliding material diverted river,which cause collapse of public housing and destruction of related facilities,economic loss is large.Based on geology and precipitation,it comprehensively analyzes the formation mechanism of the landslide and explains the reasons for the formation of the disaster.The landslide is the result of many factors,but the role of each factor is different.The main factors are storm water,geological conditions of being easy to slide,and irrational human activities.Powerful rain played a erosion,jacking,wedge cracking,motivate role.The course of the landslide includes four steps：namely groundwater convergence-jacking the landslide body,river rise-scouring the foot,squeeze-wedge crack and collapse crack-slide.It has some guidance for prevention disaster work of disaster risks point in Southwest China to depthly study the formation conditions and the presence mechanism of Gufeng village landslide in Fankuai town.