库水位变化下滑坡渗流机制与稳定性分析  

Seepage and stability analysis of landslide under the change of reservoir water levels

作　　者：张旭[1] 谭卓英[1] 周春梅[2] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083 [2]武汉工程大学资源与土木工程学院,湖北武汉430073

出　　处：《岩石力学与工程学报》2016年第4期713-723,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51174013);国家自然科学基金青年科学基金项目(41002112)~~

摘　　要：基于非饱和土力学理论建立渗流场–应力场的流–固耦合计算模型,考虑土–水特征曲线与渗透特征,将孔隙水压力分布和非饱和土强度理论应用到极限平衡法中,并与有限元法结合,对库水作用下的三峡库区巫峡段龚家坊堆积层滑坡稳态–瞬态进行渗流、稳定性、应力应变的饱和–非饱和数值计算。采用Geo-studio软件中的Seep模拟库水对滑坡体作用及地下水位变化;并与Slope结合,进行极限平衡与流固耦合的稳定性计算;采用Sigma有限元分析方法进行非饱和非稳定渗流与应力–应变分析。揭示了孔隙水压力差的消散变化以及浸润线滞后库水的时间效应,水分在坡体内运移与土体变形相互影响的空间效应,表明水在坡体中起到了顶托、楔裂、促动的作用,坡顶张拉裂隙积水对稳定不利,前缘稳定,滑坡中后缘起着推移作用,是控制整体稳定的关键,体现了渗流–应力耦合作用下库区抗滑桩作用体系的防治效果。Fluid-solid coupling models were established based on the unsaturated soil mechanics. The pore water pressure distribution and unsaturated soil strength were applied to the limit equilibrium method considering the soil-water characteristic curves and the seepage characteristics. Combined with the finite element method,the numerical computations to the seepage,the stability and the stress-strain with saturated and unsaturated properties under steady-transient conditions were carried out to Gongjiafang colluvial landslide under the action of reservoir water in Wuxia gorge section,Three-Gorges reservoir. The Seep module was used to simulate the influence of water on landslide and the change of underground water levels. The calculations of the limit equilibrium and stability of the fluid-solid coupling were carried out with Geostudio-slope. The Sigma software was applied to analyze the unsaturated-unsteady seepage,stresses and strains. The dissipation of the pore water pressure difference,the time effect of seepage line lagging behind the reservoir water and the space effects of the mutual impact between the moisture migration and soil deformation in the slope were revealed. The water in the slope played a role of jacking,wedging and actuation. The hydrops in the top tensile crack is disadvantage to slope stability. The leading edge of the slope was steady while the middle and latter edge played a role of pushing and controlled the overall stability,which reflected the protective effect of the anti-slide piles under the coupled action of seepagestress.

关 键 词：边坡工程 库水位 稳定性 渗流 滑坡 数值分析 

分 类 号：P642[天文地球—工程地质学]