摘要
在库水位波动和降雨作用的共同影响下,库岸滑坡的变形规律往往更为复杂。以三峡库区麻柳林滑坡为例,基于野外调查、钻探编录、深部位移监测以及数值模拟等手段,分析了库水位波动和降雨作用下滑坡变形特征及演化规律。结果表明:麻柳林滑坡在粉质黏土层和块石层交界处发育一个次级滑带,目前该滑坡主要沿次级滑带运动,导致次级滑动的原因与坡体物质的差异性有关;S i(S f)指标分析法揭示滑坡的滑带还未完全破坏,滑坡仍处于蠕变状态;根据三峡水库水位调度规律,将一个完整水文年划分为6个阶段,数值模拟结果表明滑坡在库水位缓慢下降阶段变形速率较小、在快速下降阶段和低水位阶段变形速率持续增大、在快速上升阶段和缓慢上升阶段以及高水位阶段变形速率则保持平稳。其中,降雨的直接影响和降雨导致库水位波动进而对滑坡变形造成的间接影响,使得麻柳林滑坡在低水位阶段的变形显著增加、稳定性最差,应加强该时段内滑坡的监测和预警。
The deformation characteristics of reservoir landslides are more complicated under the combined effect of water level fluctuation and rainfall.Taking the Maliulin landslide in the Three Gorges Reservoir area as a case study,this paper studies the deformation and evolution characteristics of the landslide according to field investigation,drilling records,deep displacement monitoring and deformation simulation.The results indicate that a secondary shallow sliding surface is detected between clay layer and rock-block layer,which controls its current activities.This phenomenon is mainly caused by the differences of landslide material composition.The S i(S f)parameters shows that the sliding zone of the Maliulin landslide has not been totally destroyed and the landslide keeps creep deformation at present.The reservoir water level fluctuation can be divided into six periods according to its annul variation.The landslide keeps stable during water level slow drawdown period but deforms intensely during the periods of rapid drawdown and low water level.During the periods of reservoir water level rapid rise,slow rise and high water level,the landslide has mere deformation.It should be noted that the direct effect of rainfall and its indirect effect through reservoir water level fluctuation leads to intense deformation and annual minimum factor of safety for the landslide.More early warning work can be implemented for the Maliulin landslide during the period of low water level.
作者
杨背背
殷坤龙
梁鑫
赵海燕
Yang Beibei;Yin Kunlong;Liang Xin;Zhao Haiyan(School of Civil Engineering,Yantai University,Yantai Shandong 264005,China;Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China)
出处
《地质科技通报》
CAS
CSCD
北大核心
2020年第2期122-129,共8页
Bulletin of Geological Science and Technology
基金
国家重点研发计划资助项目(2018YFC0809400)。
关键词
三峡库区
库水位波动
降雨
库岸滑坡
变形演化
Three Gorges Reservoir area
water level fluctuation
rainfall
reservoir landslide
deformation evolution
