库水位升降对边坡内渗流场的影响

Effect of Rise and Fall of Reservoir Water Level on Seepage Field in Slope

针对库水位升降过程中岩质边坡内渗流场的变化影响工程稳定性的问题,以四川雅安大岗山水电站右岸边坡V-V横剖面为对象,研究库水位变化时边坡内孔隙水压力和渗流场的变化规律。结果表明:边坡坡表孔隙水压力及渗流矢量受库水位升降的影响较大,而深部岩体孔隙水压力及渗流矢量受库水位变化的影响在一定时间内是有限的,并滞后于坡表;边坡内形成近似定常流后,坡体内大部分区域内岩体的渗流场趋于稳定,但不良地质结构面(卸荷裂隙带、断层等)处渗流速度仍很大。

In view of the problem that the engineering stability of rock slope was influenced by the change of seepage field under the condition of the rise and fall of reservoir water level,the V-V cross section of the right bank slope of Ya’an Dagangshan Hydropower Station in Sichuan province was taken as the research object to study the variation law of pore water pressure and seepage field in the slope under the condition of reservoir water level rise and fall.The results show that the pore water pressure and seepage vector on the slope surface are greatly affected by the reservoir water level fluctuation condition,while the pore water pressure and seepage vector of deep rock mass are limited by the reservoir water level change in a certain period of time,and lag behind the slope surface of the slope.The direction of seepage vector in slope changes with the change of reservoir water level.The seepage field of the rock mass in most areas of the slope is stable after the approximately steady flow is formed in the slope,but the seepage velocity is still very large at the surface of unloaded fracture zone and other bad geological structures.