【摘要】 建立了分析在非平稳地震动过程中重力坝失效路径可靠度的计算方法。首先,说明了指定的失效路径的失效概率与失效路径上的单元的失效概率的关系。其次,使用了虚拟变量代换了所需求得未知变量,简化了使用一次二阶矩法求解梯度的过程。然后,使用了虚拟激励法计算了响应位移的方差,并推导了单元第一主应力的均值与方差的求解公式,从而为上一步的计算提供了参数。最后,提出了一种搜索可靠度最小的失效路径的算法。计算结果表明,该文的方法收敛速度较快,具有很好的实用性。更多还原

【Abstract】 An improved method is proposed for the analysis of failure path reliability in a concrete gravity dam under non-stationary ground motion processes.Firstly,the relation between failure probability of failure path and elements in failure path was given.Then,the demand variables were replaced by dummy variables in order to simplify the process of solving the gradient in the first-order second-moment method.And the required parameters were obtained through a deducing pseudo excitation method and some other formulas.Finally,an algorithm was proposed to search the minimal reliability failure path.The calculation result shows that this method has high practicability and a fast convergence speed.更多还原