基于组合赋权法的城市桥梁可靠性模糊综合评价

Fuzzy comprehensive evaluation of urban bridge reliability based on combination weighting method

为评估城市桥梁的可靠性,预防桥梁发生安全事故,考虑到城市桥梁评估的多标准、多因素需求以及评估体系建立的复杂性、模糊性,结合城市桥梁结构特点及规范要求,建立桥梁结构可靠性综合评价指标体系,采用改进的层次分析法(AHP),通过1—9标度法和自然指数标度法构建判断矩阵,确定评价体系各级指标主观权重,通过熵权法(EWM)确定各级指标客观权重,组合2种方法对指标进行赋权。引入模糊理论,选取柯西分布隶属函数并围绕桥梁结构工程特点进行修正,再计算各级指标隶属度矩阵值;并以某桥梁结构工程实例验证构建的指标体系和计算方法。结果表明:结合行业规范和专家经验确立评价指标体系,在现有研究的基础上使用改进AHP方法并引入模糊理论,能够提高桥梁可靠性评估的客观性和准确性。

In order to evaluate the reliability of urban bridges and prevent safety accidents of bridges,the multi-standard and multi-factor requirements of urban bridge evaluation and the complexity and fuzziness of the evaluation system were considered.A comprehensive evaluation index system for bridge structure reliability was established according to the structural characteristics and code requirements of urban bridges.An improved AHP was adopted to construct a judgment matrix through the 1-9 scale method and the natural index scale method,so as to determine the subjective weights of indexes at all levels of the evaluation system.The objective weights of indexes at all levels were determined through the EWM,and the indexes were empowered by combining the above two methods.The fuzzy theory was introduced,and the Cauchy distribution membership function was selected and corrected based on the characteristics of bridge structure engineering.Then the membership matrix values of the indexes at all levels were calculated.The index system and calculation method were validated in real bridge structure engineering.The results show that combining industry codes and expert experience to establish an evaluation index system,using an improved AHP based on the existing research,and introducing fuzzy theory can enhance the objectivity and accuracy of bridge reliability evaluation.