水库蓄水对库底沉降影响的数值分析

抽水蓄能电站常采用沥青混凝土进行库底防渗护面处理，过快的蓄水速率和过大的蓄水水头可能导致库底护面开裂。以某抽水蓄能电站的上水库为例，用考虑Biot固结理论的平面有限元法，在依据沉降观测点实测资料优化确定地基土模型参数的基础上，分析了水库蓄水速率和蓄水水头对库底沉降量、沉降率及库底沥青混凝土应变率的影响。结果表明，蓄水速率对地基的最终沉降值影响不明显，而在蓄高水位历时内，地基的沉降增量和最大沉降率均与蓄水速率和蓄水水头有很好的相关性，沥青混凝土的最大应变率仅与蓄水速率相关。

Numerical analysis of influence of filling on settlement of reservoir foundation

Pitch concrete is often used as seepage prevention of the bottom of pumped storage reservoir. Crack may be found in it if the filling rate is too larger or the filling water head is too high. In this study, based on an example of the upper reservoir of a pumped storage power station, the influences of the filling rate and filling water head on the settlement, settlement rate of the reservoir foundation, and the strain rate of the pitch concrete are analyzed. Before analyzing, the model parameters of some materials are obtained based on observed settlement data and initial model parameters using an optimum method. The 2D FEM and Biot consolidation theory are used in this study. The results of analysis indicated that the filling rate has little effect on the ultimate settlement of the foundation, but has larger influence on the settlement increment during filling, the maximum settlement rate of the foundation and the maximum strain rate of the pitch concrete; and the filing water head has little effect on the maximum strain rate of the pitch concrete, but has larger influence on the settlement increment during filling, the maximum settlement rate of foundation. The relationships between the settlement increment during filling and the filling rate and filling water head, between the maximum settlement rate and the filling rate and filling water head, and between the strain rate of pitch concrete and the filling rate are also given.