【摘要】 考虑可靠性分析模型中随机参数的模糊性,利用一次二阶矩法建立模糊随机可靠性分析模型。利用分解定理,取一系列λ截集,将模糊数转换为一系列区间数进行运算,得到一种模糊随机可靠度的计算方法即λ截集法。分别建立倾覆失稳和滑移失稳2种失稳模式下的结构功能函数,确定2种失稳模式下模糊随机变量,利用模糊随机可靠度的计算方法分别对2种失稳模式进行计算,得到2个相应的模糊随机可靠度指标及失稳概率。将该计算方法与相关文献提供的计算方法进行对比。研究结果表明:由λ截集法与其他算法所得计算结果差异明显,其原因是其他算法把挡土墙的结构功能函数Z假设成正态分布,从而得出的概率密度函数f(Z)有误差;采用λ截集法计算的模糊随机可靠度更符合实际情况。更多还原

【Abstract】 Considering the fuzzy uncertainties of the parameters of stochastic variables,FOSM(First order second moment) was utilized and fuzzy random dependability analyzing model was set up.By using decomposing theorem and introducing λ cut set,fuzzy numbers were convened into a series of interval numbers and fuzzy random reliability computing technology was received.The major unstable modes of gravity retaining walls are overturning and sliding.Two performance functions against overturning and sliding of gravity retaining walls were established and the fuzzy random variables were confirmed for the two kinds of invalid modes.Two kinds of failure modes are calculated separately by using fuzzy random reliability computing technology,and two fuzzy random reliability indexes and corresponding failure probabilities are received.Comparing with computing technology proposed in relevant literature,the result of calculation shows that the difference of calculation result is obvious.The reason for producing the difference is that other methods supposes performance functions Z of the gravity retaining wall into normal distribution,there exists error to obtain the probability density function f(Z) in this treatment.Fuzzy random reliability value calculated by λ cut set way is in accordance with the actual results further.更多还原