库水升降作用下的类土质岸坡变形与破坏试验分析  

Analysis on Deformation and Failure Based on Test Model of Earthy-soil Bank Slope under Reservoir Water Level Fluctuation

作　　者：唐红梅[1] 周云涛[2] 李俊男 TANG Hongmei;ZHOU Yuntao;LI Junnan(Institute of Geotechnical Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Institute of Exploration Technology CAGS,Chengdu 611734,China)

机构地区：[1]重庆交通大学岩土工程研究所,重庆400074 [2]中国地质科学院探矿工艺研究所,四川成都611734

出　　处：《灾害学》2018年第3期74-79,共6页Journal of Catastrophology

基　　金：国家自然基金项目(51378521);国家自然基金项目(51678097);重庆市重点基金项目(cstc2013jj B30001)

摘　　要：三峡库区类土质岸坡广布,受库水位升降、浸泡等影响,其变形与破坏演化过程极为复杂,其防治十分困难。基于3D激光扫描技术,通过对库区水库运行期间类土质岸坡模型试验模拟其变形与破坏,进行分析获得了类土质岸坡变形破坏演化特征:蓄水浸泡软化诱发类土质岸坡变形破坏具有突发性特征,岸坡破坏发生在坡脚低水位有限的30%浸泡区域,且呈现渐进性破坏模式,孔隙水压力曲线变现为相对稳定、波动以及稳定增长3个阶段,此波动是库岸裂纹发育的直观表征;受库水浸泡作用影响使类土质岸坡坡中出现沉降变形位移显著,位移监测显示在高水位线附近监测的位移出现突变,在岸坡后缘形成卸荷裂隙区域显著;试验库水位降落时致坡内形成的渗透流驱动力显著,诱发坡体内坡中位置产生大量平行裂缝,朝坡脚局部发生偏转,孔隙水压力曲线变化分为缓慢降低、快速下降和负孔隙水压力三个阶段,负孔隙水压力阶段是岸坡裂纹快速贯通阶段;再次蓄水浸泡使裂缝横向扩展贯,加剧诱发类土质岸坡坡脚大面积破坏垮塌,有可能形成整体性滑移。为进一步研究类土质岸坡变形破坏模式与防治具有一定借鉴意义。The earthy-soil bank slope is widely distributed in Three Gorges Reservoir area. The deformation and failure evolution of earthy-soil bank slope is all the complex process because of water level fluctuation in the Three Gorges reservoir. and controlling is very difficulty .Based on the 3D laser scanning technique,the model test of earthy-soil bank slope simulates their deformation and failure during the operation of the Three Gorges reservoir.Many test data are obtained and analyzed the geomorphic evolution characteristics of the bank through the model test of the soil bank.It is embodied in several aspects：first,water storage and dip softening induced earthy-soil bank slope deformation and failure is happened very suddenly.The destruction process presents the progressive failure formality,and the slope failure occurs at the foot of slopes formed about the thirty percent of soak area near the low water level.The curves of pore-water pressure perform 3 stages：relatively stable stage, fluctuation stage and steady increasing stage. The fluctuation is visual representation of crack development of bank slope.Secondly,due to the effect of reservoir water dip softening,a large area of settlement deformation occurs in earthy-soil bank slope,displacement monitoring indicates that the shifting change suddenly near the high water level,then the unloading area is formed in trailing edge of earthy-soil bank slope;thirdly,the seepage flow driving force formed by the drawdown of reservoir water level causes a large number of parallel cracks in the slope,and it will deflect partly towards the foot of slopes.The curves changes of pore-water pressure perform 3 stages：slowly decreasing stage, rapidly decreasing stage and negative pore-water pressure stage. The negative pore-water pressure stage is the stage of rapid crack coalescence of bank slope;meanwhile,the second store water induced that the crack are able to scale horizontally,and exacerbated a large area of collapse occurred,with the further expansion of the crack,may

关 键 词：库水升降 岸坡变形 渐进破坏 试验 类土质岸坡 

分 类 号：P642.2[天文地球—工程地质学] X43[天文地球—地质矿产勘探]