剑科心墙堆石坝三维地震反应分析

3D Seismic Response Analysis of Jianke Rockfill Dam with Core Wall

采用三维非线性动力有限元分析方法,针对处于岷江断裂带和龙门山断裂带的剑科水电站工程的心墙堆石坝,进行了坝体在人工地震波作用下的地震反应计算分析,研究了该坝的地震位移、加速度反应、动剪应力、残余变形以及液化反应。计算结果表明,坝体最大加速度放大倍数为3.23,放大效应明显;廊道顶部最大动剪应力为150 kPa,动强度满足要求;最大永久沉降量约为坝高的0.139%,分布符合一般规律;动孔压比较小,不会发生液化破坏。坝体各项抗震指标均在合理范围内,大坝抗震稳定性良好。

In view of the rockfill dam with core wall of the Jianke Hydropower Station located in the Minjiang fault zone and Longmenshan fault zone, the dynamic response of dam body under the action of artificial seismic waves was calculated and analyzed by using 3D nonlinear dynamic FEM. And the earthquake-induced displacement, acceleration response, dynamic shear stresses, residual deformation and liquefaction of the dam were studied. The results showed that the maximum amplification coefficient of acceleration of the dam is 3.23, so that its amplification effect is obvious. The maximum dynamic shear stress is 150 kPa at the top of gallery, which meets the dynamic strength requirement. The maximum permanent settlement is about 0.139% of dam height and its distribution complies with to common rules. Liquefaction failure could not happen due to small dynamic pore water pressure ratio. All the earthquake resistance indexes are in a reasonable range so that the dam has good seismic stability.