【摘要】 通过动力有限元时程法分析了金沙江阿海混凝土重力坝在设计地震动(0.344g)作用下的动态响应,计算模型考虑了动水压力作用、大坝-岩基相互作用,用黏弹性吸波边界模拟了地震动能量向无限远域逸散的地基"辐射阻尼"效应。通过将坝体惯性力时程极大值与振型分解反应谱法的惯性力极值对比,从而验证了复杂动力数值模拟结果的正确性,为后续分析打下了基础。采用沿滑面的应力积分法得到了大坝沿建基面的瞬态抗滑安全系数时程。计算结果表明:阿海重力坝在设计地震动(0.344g)作用下的安全系数时程的极小值为1.146,大坝整体稳定性良好,可不采取提高整体抗滑稳定性的工程加固措施。作为重大工程典型实例研究,采用的计算方法和所得结果对类似大坝工程抗震研究具有参考意义。更多还原

【Abstract】 Time-history analysis using dynamic FEM is employed to compute the seismic response of Ahai concrete gravity dam at the Jinsha River subjected to design earthquake loading.The hydrodynamic pressures and dam-foundation interaction are considered in the FEM model;and the foundation radiation damping effect of the seismic motion energy dissipating towards infinite domain is simulated as well.Firstly,the complex numerical simulation results are validated by comparison of dam body’s maximum inertial forces between time-history analysis and spectrum method.Then,the following evaluation of the sliding stability of the dam can be conducted.The time history of anti-sliding safety factor is obtained using stress integration along the dam-base sliding interface.Because the minimum value of safety factor histories is 1.146;it can be concluded that the Ahai dam has a relatively enough high capability for earthquake resistance that the reinforcement to improve the anti-sliding stability is not needed.The outcome of this study should be of interest and useful to professionals involved in the design of similar large gravity dams.更多还原