神树水电站混凝土面板堆石坝高趾墙及面板动力响应分析

The Dynamic Response of the High-toe Wall and Its Concrete Facing of Shenshu Hydropower Station Rockfill Dam

在混凝土面板堆石坝抗震设计中,主要采用拟静力法,无法考虑地震动作用。为了探讨混凝土面板堆石坝高趾墙及面板在地震作用下的动力响应行为,运用有限差分法数值软件FLAC3D,通过建立神树水电站包含各种堆石材料的混凝土面板堆石坝系统,在地震动激励下进行计算模拟。结果表明:高趾墙对此混凝土堆石坝有重要作用,而高趾墙底部锚杆对坝体整体位移量影响极小,但在地震激励下,锚杆轴力达到了较大值,其轴力随着地震时程的增加出现衰减。混凝土面板监测点峰值加速度放大系数Kpga在铺盖以下随着高程的增加而增加,在铺盖以上出现波动。

In the aseismic design of rockfill dam with concrete facing ,pseudo-static method is mostly adopted without considering the ground motions .In order to study the dynamic responses of high-toe wall and its concrete facing of the rockfill dam in Shenshugou hydropower station under seismic condition ,a numerical model of the dam was established with the FEM software FLAC3D .By inputting typical seismic waves to the dam system ,the whole history of the earth-quake wave through the dam was simulated and the dynamic response of the dam system was calculated .Results indicate that the high-toe wall is very important for the dam ,and the bolt at the bottom of the high-toe wall has minimal impact on the dam displacement .But under seismic excitation ,the bolt axial force reaches a larger value ,and then decreases with the increase of the earthquake time history .The PGA of monitoring points on the concrete facing increases with its eleva-tion under the blanket ,while fluctuates above the blanket .