【摘要】 早期建造的混凝土重力坝随着运行年限的增加,坝体的老化特征和损伤积累日益突出,其承载能力和抗震性能的评价问题已成为研究的重点内容。本文基于化学-湿-力耦合作用原理的连续损伤力学理论,考虑了由于力学性能退化和环境条件引起的老化因素对坝体动力损伤的影响,使用二维动力有限元-边界元混合法对丰满大坝的某溢流坝段进行了计算分析。结果表明,本文所提出的数值模型能够体现出混凝土性能的退化过程,能够预测长期运行老化混凝土重力坝的地震反应,从而为现正运行的混凝土大坝的抗震安全评价和鉴定探索了新的方法和途径。更多还原

【Abstract】 The aging characteristics and accumulation of damage of the concrete gravity dam built in the early years is obvious with increasing age. The evaluation of structural capacity and seismic performance of old dams has become the major concerning in engineering. A time-dependent isotropic degradation index is evaluated on the basis of hygro-chemo-mechanical effect for aged dams. The proposed two-dimensional dynamic finite element / boundary element methods can be used to analyse the seismic responses of a spillway section of the Fengman dam by taking into account the influence of mechanical degradation and harsh environmental effect. The numerical procedure presented in this paper can account for the concrete degradation process and can predict the seismic behavior of the dam at a certain age,in order to explore new ways and means for the seismic safety evaluation and identification of active-duty concrete dam.更多还原