事故树结构重要度的求解方法

Solution method for accident tree structural importance

目前求解事故树结构重要度主要有三种求解法。针对三种方法求解时会出现结果不一致的现象,以一个小型事故树实例,分别采用三种求解法进行求解计算,寻求其各自的特点和适用环境。当事故树中基本事件数目较多时,采用最小割(径)集法求解;当需要得到精确计算结果时,采用结构重要度系数法求解;当采用最小割集(最小径集)法求解结构重要度排序存在不一致时,可采用结构重要度系数法或概率重要度性质法求解。行车起重设备吊物坠落事故实例,验证了事故树结构重要度求解方法的有效性。该研究为恰当的选择和使用结构重要度求解法提供了参考。

Aimed at addressing the inconsistency resulting from use of the three prevailing methods for calculating structural importance of accident tree, this paper features the use of the small accident tree case for developing three solutions, as is required, so as to identify the how and where they behave bet- ter. The proposed methods range from the smallest cut set designed for the larger number of basic events occurring accident tree, to the structure importance degree coefficient method suited for more accurate calculation and the structure importance degree coefficient method or probability importance degree coeffi- cient method tailored for addressing the inconsistence in sequence due to the of the smallest cut set. The analysis of the accidents caused by falling or fallen objects as is the case with lifting equipment proves the validity of solution method for accident tree structural importance. The study provides reference for proper selection and application of structural importance solution.