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面板堆石坝具有良好的抗震能力的特性已被数次强震证明,但其动力反应依然是一个值得关心的问题,尤其是在坝高跨入300m级、河谷地形条件较复杂等情况下。采用等价黏弹性模型,对复杂地形(河谷呈不规则“W”形)条件下高面板堆石坝的动力反应进行分析,得出复杂地形条件下混凝土面板堆石坝(CFRD)坝体、面板的动力反应分布较单一地形条件下复杂,但规律基本相同;最大的动力反应加速度发生在坝体最大断面坝顶位置,最大竖向动位移约为坝高的0.3%;受右岸古河床和左岸陡边坡的影响,右岸的轴向和顺河向动力加速度放大倍数大于左岸,垂直向动力加速度放大倍数反之;古河床位置有一个明显的沉降区域。根据分析结果,复杂地形条件下高面板堆石坝的破坏形式主要有下游坝坡失稳破坏、面板拉裂和震陷超标等。最后提出可采取的抗震措施以供讨论。
The rockfill dam with good seismic performance has been proved by several strong earthquakes, but its dynamic response is still a concern, especially when the dam height is 300m and the terrain conditions in the valley are complex. The equivalent viscoelastic model was used to analyze the dynamic response of high concrete facing rockfill dams under complex terrain (valleys with irregular “W ” shape), and the concrete faced rockfill dam (CFRD) dam under complex terrain conditions The dynamical response distributions of body and panel are more complicated than those of single terrain, but the laws are basically the same. The maximum dynamic response acceleration occurs at the top of the dam with the largest cross section and the maximum vertical displacement is about 0.3% of the dam height. On the right bank, the amplitudes of dynamic accelerations in the axial direction along Heshun River are larger than those in the left bank, and vice versa. On the contrary, there is an obvious settlement area in the ancient riverbed. According to the analysis results, the failure forms of high concrete face rockfill dams under complicated terrain conditions mainly include the instability failure of the downstream dams, cracking of the panels and excessive seismicity. Finally, the seismic measures can be taken for discussion.