某高面板堆石坝地震反应特性分析

针对高面板堆石坝的结构特性, 采用三维非线性有限元技术, 对大坝的地震反应特性及抗震安全性进行计算 分析。动力计算中坝体材料及覆盖层按照等效线性黏弹性模型考虑围压效应进行模拟, 混凝土面板动力计算分析 采用线性弹性模型, 并依据考虑围压效应的残余体应变及残余轴应变的动应力2残余应变模型对某高面板堆石坝进 行坝体地震工况下永久变形计算。计算结果显示: 顺河向最大永久变形为 15 cm, 竖直向最大永久变形为 49 cm, 均 发生坝顶位置, 地震引起的竖向变形为坝高的 01 4% ; 三维动力参数敏感性分析表明, 堆石体的水平绝对加速度反 应极值为 9 m/ s2 , 最大放大系数为 41 2, 堆石体、面板最大地震反应位于坝顶局部位置, 存在明显的鞭稍效应, 但坝 体地震反应的分布规律一致, 坝体及面板抗震安全性较好。 In view of the structural characteristics o f the hig h face ro ckfill dam, w e calculated and analyzed the dynamic response char acteristics and the seismic safety of the dam by the t hr ee2dimensional nonlinear f inite element method. In the dy namic calcu2 latio n, the dam material and ov erburden lay er wer e simulat ed acco rding to the equiv alent linear visco elastic model with consider2 ation to the confining pressure effect. A linea r elast ic model was used fo r the calculatio n of concrete dy namics. The permanent deformatio n o f the dam was calculated based o n the dy namic str ess2r esidual strain mo del, w hich co uld be used to calculate the residual bo dy strain and r esidual ax ial str ain. T he r esults show ed that the max imum permanent defo rmatio n along the river w as 15cm and the max imum permanent deformat ion in the v ertical directio n was 49 cm; bo th at the dam crest. I n the thr ee2dimen2 sio nal analy sis, the ho rizo ntal abso lute accelerat ion r esponse of the r ockfill w as 9 m/ s2 , and the max imum amplificatio n fact or was 41 2. The maximum earthquake r esponse of the ro ckfill and the panel occurred at the to p of the dam, show ing an obvious whiplash effect. 国家自然科学基金( 51779155) ; 中央级公益性科研院所基本科研业务费专项( Y717006; Y717012; Y718002)