摘要
三峡库区藕塘滑坡位于重庆市奉节县安坪镇长江右岸,是由于三峡水库蓄水引起的巨型顺层基岩滑坡,面积约1.78 km2,体积约9.0×107m3,是近年来三峡库区重大滑坡灾害之一。基于大量的野外地质调查以及室内试验分析,详尽阐述了滑坡地质地貌及地质结构特征,运用地貌学与工程地质力学理论方法从地质和环境因素两方面进行滑坡成因分析,提出了藕塘滑坡的形成机制及演化过程,并对其变形发展的趋势进行了预测,得出如下结论:(1)藕塘滑坡为巨型顺层岩质滑坡,平面形态具有多级多期次滑动特征,空间形态具有视向倾斜滑动特征,受控于稳定山体的阻挡;(2)顺向单斜地貌,节理裂隙发育,具有软硬夹层的地质结构是滑坡形成的控制因素;长江深切侵蚀为滑坡提供了动力基础和运动空间;集中降雨和三峡水库蓄水是导致滑坡复活的主要诱发因素;(3)各级滑坡的形成机制不同,一级滑坡为"拉裂-滑移(弯曲)-剪断"模式,二级滑坡为"平面滑移"模式,三级滑坡为"滑移-剪断"模式;(4)现阶段该滑坡以局部浅层失稳破坏形式为主。最后,建议加强三峡库区集中降雨和库水位波动联合作用下滑坡诱发机理与监测预警研究工作。
The Outang landslide is situated on the right bank of the Yangtze River at Anping Town in Fengjie County of Chongqing Municipality. The size of the large consequent bedding rockslides is about 9. 0 × 107m3 in volume and about 1. 78 km2 in area,which were caused by the impoundment of the Three Gorges Reservoir,which is one of the serious landslide disasters in this area. On the basis of field investigation and experimental analysis,the special geologic environment and characteristics of the Outang landslide are studied in detail.Using the first-hand data,the origin of the Outang landslide is analyzed from two aspects： geologic origin and the environment origin by utilizing the theories of geomorphy and engineering geology mechanics. The formation mechanism of the Outang landslide is proposed. The deformation trend of the landslide is also predicted. The result shows that（ 1） the Outang landslide is multi-phase ancient consequent bedding rockslides with three landslide phase;（ 2） the particular geological structure,such as consequent monoclinic landform,developed joint fissures,the soft-hard interlayer,is the control factor of landslide formation; deeperosion of the Yangtze river provides a dynamic basis and movement space for the landslide formation; the high intense and large rainfall and the water storage of the Three Gorges Reservoir are the main triggering factors of landslide revival;（ 3） each phase of the Outang landslide is with different formation mode： the first phase landslide is tension-creep（ bending）-shearing model; the second phase landslide is planar slip model; the third phase landslide is creep-shearing model;（ 4） at this stage,the major failure mode of the landslide is the local buckling failure. It is suggested to strengthen the study of the landslide triggering mechanism under the effects of intense rainfall and water level fluctuations.
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2015年第6期145-153,共9页
Hydrogeology & Engineering Geology
基金
"十二五"国家科技支撑项目(2012BAK10B01)
国家自然科学基金项目(41172254)
中国地质调查局基金项目(1212011220124)
关键词
三峡库区
顺层滑坡
藕塘滑坡
滑坡成因
Three Gorges Reservoir
consequent bedding rockslides
Outang landslide
landslide origin
作者简介
代贞伟（1986-），男，博士研究生，主要从事工程地质与地质灾害研究工作。E-mail：daizhenwei@163．com
