高拱坝的动力非线性分析

强地震时，高拱坝中上部因动力放大效应而成为抗震薄弱部位，各项段间的伸缩横缝难以承受较大的拱向拉应力而开裂，拱坝不能现视为整体结构而作线弹性分析。为此，以三维非线性接缝单元模拟坝体分缝，采用基于动态子结构理论的非线性动力分析方法，分析研究伸缩横缝对高拱坝地震反应的影响。研究表明，强烈地震时伸缩横缝反复张合引起显著的坝体应力重分布，大大减少开裂区附近的拱向拉应力而使坝体中部下游面的梁向拉应力有一定增加

Non-linear dynamic analysis on high arch dam

When strong earthquake happens, the middle and upper parts of high arch dam will become the weak earthquake resistance parts because the power amplification effect. The transverse expansion joints between the damsections will crack because they are difficult to bear the comparative arch tensile stress so that the arch dam could not be taken as the monolithic structure for conducting the linear elastic analysis. In this paper, by taking three-dimensional non-linear dynamic joint element to simulating the dam joint and using non-linear dynamic analysis methodbased on the dynamic sub-structure theory, the earthquake response effect of transverse expansion joints on the high arch dam has been analyzed and studied. It showed that when strong earthquake happens, the repetitive open and close of transverse expansion joints would cause obvious re-distribution of dam stress which greatly reduce the arch tensile stress around the cracked areas so that the beam tensile stress would be increased on the downstream surface of the middle dam body.