不同地震输入对混凝土面板堆石坝动力反应的影响

Influence of different seismic input on dynamic response of concrete faced rockfill dam

研究了不同地震输入对面板堆石坝动力反应的影响。认为ＤＬ５０７３－１９９７规范规定按拟静力法进行土石坝抗震计算时,顺河向加速度放大倍数在设计烈度为７、８、９度时分别取３．０,２．５,２．０是合适的。但竖向地震加速度代表值取水平向的２/３,在狭窄河谷条件下偏小。面板堆石坝动力反应分析宜采用顺河向和坚向２分量地震输入或３分量地震输入。

Dynamic responses of concrete faced rockfill dam subjected to different excitations, such as different seismic intensity or different directional components of input, have been studied. The analysis shows that the horizontal acceleration amplification of 3.0, 2.5, 2.0 along the stream is appropriate for the design earthquake intensity of 7, 8 and 9 respectively. But for the three intensities it is not enough to take vertical -to-horizontal acceleration ratio as 2/3 when the river valley is narrow. Dynamic analysis of concrete faced rockfill dam should use 2 directional (horizontal and vertical) or 3 directional component earthquake records.