本文提出基于概率密度演化方法的地下结构可靠度分析,通过求解极限状态函数的概率密度演化方程,可以得到响应量的概率密度函数曲线。相比于传统的随机模拟方法,概率密度演化方法考虑了样本点之间的概率联系,因此在求解效率以及精度上都得到大大提高。文中结合上海市轨道交通M6线地铁工程进行了基于概率密度演化方法的可靠度分析,与随机模拟的结果相比表明,基于概率密度演化方法的地下结构可靠度分析方法具有更好的效果。文中还介绍了基于等价极值事件的结构体系可靠度分析方法,并将等价极值事件的基本思想推广到复杂失效准则下地下结构的可靠性分析之中。结果表明此方法可以对地下结构可靠度给出较为准确的评价。
The reliability analysis of underground structure based on probability density evolution method was presented. The probability density function curve was obtained by solving the probability density equation of limit state function. The probability relation of different sample point was considered in the probability density evolution method, so its result has high accuracy and efficiency by contrast with the traditional stochastic simulation. The reliability analysis of underground structure based on probability density evolution method was used on the metro line 6 in Shanghai. The results of reliability assessment were compared with those evaluated by Monte Carlo simulation. The investigation shows that the proposed approach has better effect. At last, the structural system reliability based on equivalent extreme value event was also discussed and applied to reliability analysis of underground structures under complex failure criteria. The results clearly prove that this method can give accurate evaluation on the reliability of underground structures.