The practical seismic damages of gravity dams often occur on the middle and upper part of the dam body, where the dam hole-opening are arranged, so that the dam head with openings become a weak spot for anti-seismic of gravity dams. Tak-ing a powerhouse dam section of a scheduling RCC gravity dam for instance, we establish a three dimensional analytical model that considers the dam-foundation-water interaction based on ADINA. In this way, the characteristics such as natural vibration characteristic, dam displacement, principal tensile stress and crack propagation of dams with or without openings, were re-searched under strong earthquake. The results show that dam hole-opening has more impacts on local stress rather than on inte-gral rigidity. So in anti-seismic design of gravity dams, we should focus on the hole-opening and take measures such as arran-ging reinforcing bars and using high grade concrete.%重力坝实际震损多出现在坝体中上部,坝身孔洞也常布置于此,地震作用下坝头孔洞附近成为抗震安全的薄弱部位. 以某待建水电站碾压混凝土重力坝厂房坝段为例,基于ADINA有限元软件建立考虑坝体-地基-库水相互作用的三维有限元动力计算模型,研究了在强震作用下考虑大坝开孔与否对坝体自振特性、坝体位移、主拉应力和裂缝开展情况的影响. 结果表明,考虑坝体开孔对大坝整体刚度影响不大,但对局部应力影响显著,抗震设计须重视坝体实际开孔情况,采取加强配筋和提高混凝土标号等措施. 研究成果可为同类工程抗震设计提供参考.
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