Abstract: The opening and closing of transverse joints under strong seismic action have a significant im- pact on the dynamic response of arch dams, which is a key concern in the design of high arch dams. Us- ing the finite element time-history analysis method, taking into account of factors such as the opening of transverse joints in arch dams and the infinite foundation radiation damping, the calculation and simula- tion are conducted based on various working conditions composed of factors including normal reservoir water level and dead water level, design temperature rise and design temperature drop, and seismic loads under site-specific spectra. The analysis results show that the transverse joints in the concrete arch dam undergo repeating opening and closing during seismic response, with a relatively large opening occurring at a certain instant. However, the joint waterstop is not pulled apart. The arch stress of dam body is partially relieved, and the overall high-stress distribution of dam meets the allowable conditions, ensuring the overall stability of dam body after the earthquake.

Key words: transverse joint, opening, dynamic response, three-dimensional viscoelastic boundary, dam stability

摘要： 强震作用下横缝的开合对拱坝的动力响应影响显著，是高拱坝设计重点关注的问题。采用有限元时程分析方法，考虑拱坝横缝张开、无限地基辐射阻尼等因素，根据正常蓄水位和死水位、设计温升和设计温降、场地谱下的设计地震荷载等因素组成工况进行计算模拟。分析结果表明，横缝在混凝土拱坝地震响应中往复开合，在某个瞬时产生了较大开度，但橫缝止水不会拉开；坝体拱向应力得到一定释放，大坝整体高应力分布满足容许条件，震后坝体整体稳定性得到保证。

关键词: 横缝, 开度, 动力响应, 三维黏弹性边界, 大坝稳定性