汶川地震中紫坪铺混凝土面板堆石坝震害分析

Earthquake damage analysis of Zipingpu concrete face rock-fill dam during Wenchuan earthquake

汶川地震中,紫坪铺混凝土面板堆石坝坝坡、面板和结构缝均出现一定程度的破坏,大坝发生了整体变形.根据这些震害现象,结合振动台模型试验和数值分析的成果,从坝坡破坏性态、坝顶加速度反应、面板应力与变形、大坝的地震变形和面板缝的破坏形式几方面讨论了面板堆石坝破坏机理和抗震性能.在此基础上,对面板堆石坝抗震设计的着力点和抗震措施提出了建议:在面板堆石坝抗震设计中,高面板堆石坝上部面板在地震中可能出现的高应力区是着重点之一;应该考虑坝体地震永久变形对面板附加应力的影响;应特别注意坝顶区堆石体的稳定,建议选择钉结护面板加固方案,从而提高地震时坝顶区堆石体的整体稳定性.

The slope, concrete slabs and construction joints of Zipingpu concrete face rock-fill dam （CFRD） were obviously damaged during Wenchuan earthquake. At the same time, the strong shock induced deformation of the dam. On the basis of the failure phenomenon of Zipingpu dam, shaking table tests and numerical analysis of CFRD, the failure mechanism and aseismatic performance of CFRD including failure behavior of dam slope, acceleration response of dam crest, stress and deformation of concrete slabs, the seismic deformation of dam, and failure behavior of joints of slabs were discussed. As a result, some aseismatic design methods and measures for CFRD are suggested as follows： the stress of slab at the top of CFRD should be paid attention to, the effect of dam deformation on the additional stress of slab should be considered, and then nail-tied panel measure can increase the seismic stability of dam slope.