库水位变化和降雨条件下边坡渗流特性及稳定性分析

摘要

In Southwest of China,the geological structure is complex and the rainfall is abundant;so the influence of groundwater on the stability of reservoir slopes is relatively prominent.Taking an inlet slope of the discharge structure in that area as the prototype,the seepage and stability of the slope under different conditions of rainfall and the reservoir water level fluctuation are simulatively calculated based on saturated-unsatu-rated seepage theory,limit equilibrium theory and the finite element analysis software (Geo-Studio).The calculation results show that the groundwater level of the slope changes exactly in accordance with the reservoir water level,slope stability safety factor firstly decreases with the rise of reservoir water level,and then increases slowly.When the reservoir water level drops,the slope stability safely factor coefficient firstly decreases and then increases;and the lower the rate of decline is,the smaller the stability safety factor will be.Under the condition of rainfall infiltration,the groundwater level of the slope will rise to a certain extent;and the stability safety factor of the slope accordingly decreases at the same time.The research results can provide a reliable basis for slope stability analysis and the safe operation of the reservoir.%我国西南地区地质构造复杂,降雨充足,地下水对岸坡稳定性的影响相对突出.以该地区某泄水建筑物进口边坡为原型,根据饱和-非饱和渗流理论和极限平衡理论,利用有限元分析软件Geo-Studio,对该边坡在不同降雨及水库水位升降条件下的渗流和稳定性进行了模拟计算.结果表明:边坡内的地下水位随库水位变动而变动,边坡的稳定性系数在库水位上升时先不断减小后缓慢增大;在库水位下降时先减小后逐渐增大,且下降速率越大,稳定性系数越小;在降雨入渗条件下,边坡的地下水位会有一定的抬升,同时边坡的稳定性系数相应减小.研究结果,可为边坡稳定性分析和水库安全运行提供可靠依据.