除冰盐与冻融环境下在役混凝土桥梁耐久性评估

Durability evaluation of in-service concrete bridges under deicing salt and freeze-thaw environment

为了客观准确地评估除冰盐与冻融环境下在役混凝土桥梁的耐久性,引入基于博弈论-物元可拓理论的评估模型。根据寒冷地区除冰盐与冻融环境特点,结合该环境桥梁主要病害,建立了包含混凝土抗冻能力、混凝土护筋能力、钢筋锈蚀和环境作用4个因素的多层次评价指标体系;通过物元变换构建除冰盐与冻融环境下在役混凝土桥梁耐久性评估的物元体系,计算耐久性指标对其评估等级的关联度,采用博弈论组合赋权法确定指标综合权重,根据最大关联度原则判定桥梁耐久性等级,构建了基于博弈论-物元可拓理论的评估模型。运用该模型对青海省3座混凝土桥梁进行了耐久性评估。研究表明,评估结果与实际情况相符,验证了该模型的有效性和合理性,可为该环境混凝土桥梁的维修加固提供决策依据。

To objectively and accurately evaluate the durability of in-service concrete bridges under deicing salt and freeze-thaw environment,this paper intends to introduce an evaluation model based on game theory and matter-element extension theory.Firstly,by analyzing the influence of deicing salt and freeze-thaw environment on the durability of in-service concrete bridges in cold regions,then combined with the main diseases of the in-service concrete bridges in this environment,a multi-level durability evaluation index system of in-service concrete bridges was established,including four factors:concrete frost resistance,concrete reinforcement capacity,reinforcement corrosion,and environmental effects.Then,the matter-element system for durability evaluation of in-service concrete bridges under deicing salt and the freeze-thaw environment was constructed by matter-element transformation.The single index correlation degree of each evaluation index of concrete bridges on durability evaluation grade was calculated.The combined weighting method of game theory was used to integrate and optimize the subjective weight determined by G1 method and the objective weight determined by the entropy method,to determine the comprehensive weights of the evaluation indexes.According to the single index correlation degree and the weight value of each evaluation index of a concrete bridge,the comprehensive correlation degree of the concrete bridge to each durability evaluation grade was calculated.Then the durability grade of the concrete bridge was determined by the principle of maximum correlation degree,and the bridge durability evaluation model based on game theory and matter-element extension theory was constructed.Finally,the model was used to comprehensively evaluate the durability of three concrete Bridges in Qinghai Province,and the evaluation results were compared with the actual investigation results.The research results show that the evaluation results of the model are in good agreement with the actual situation,which verifies the effectiveness and feasibility of the model,thus providing a decision-making basis for the maintenance and reinforcement of concrete bridges under deicing salt and freeze-thaw environment.