库水骤升条件下特高心墙堆石坝渗流及坝坡稳定性分析

Analysis on Seepage and Slope Stability of Super-high Core Wall Rockfill Dam under Sudden Rise of Reservoir Water

为分析库水骤升对特高心墙堆石坝的渗流特性及坝坡稳定性的影响,以某特高心墙堆石坝实际情况为例,建立有限元分析模型,采用饱和-非饱和非稳定渗流理论,对库水骤升阶段渗流场进行了数值模拟,并将非稳定渗流场与极限平衡法相结合分析了坝坡稳定性。研究结果表明:库水骤升过程中,心墙内浸润线变化相对库水位变化表现出明显的滞后性,浸润线呈现“下凹”形状,且水位骤升速率越快,向下弯的程度也越大;库水骤升阶段,心墙内非稳定渗流等势线整体向上游偏移;库水骤升对上游坝坡稳定性具有有利影响,下游坝坡由于心墙较好的防渗性,基本保持不变。

To analyze the impact of sudden rise in reservoir water on the seepage characteristics and slope stability of a super-high core wall rockfill dam,this paper takes the actual situation of a certain super-high core wall rockfill dam as an example and establishes a finite element analysis model.It adopts the saturated unsaturated unstable seepage theory to numerically simulate the seepage field during the sudden rise stage of reservoir water,and combines the unstable seepage field with the limit equilibrium method to analyze the stability of the dam slope.The research results indicate that during the sudden rise of reservoir water,the change in the infiltration line inside the core wall shows a significant lag compared to the change in reservoir water level.The infiltration line shows a"concave"shape,and the faster the rate of water level sudden rise,the greater the degree of downward bending.During the sudden rise of reservoir water,the unstable seepage equipotential line inside the core wall shifts towards the upstream as a whole.The sudden rise of reservoir water has a favorable impact on the stability of upstream dam slopes,while downstream dam slopes remain basically unchanged due to the good impermeability of the core wall.