Research On Disease Assessment Method Of Highway Bridge Expansion Joint

The bridge expansion joint is the one of easily destroyed component in the bridge structure,of which the damage will not only cause the decrease of the comfort of driving,but also affect the bridge structure,and even cause the hidden danger of driving safety.The problems of bridge expansion joint damage degree evaluation and maintenance have to be settled urgently by highway management and maintenance department.Therefore,it is of great significance to establish a method for damage assessment of bridge expansion joint.Among the existing evaluation methods,the influence of artificial factor is inevitable in weight value of each part of the expansion joint and the evaluation method is efficient,resulting in the misjudgment of the structure in the damage evaluation.In view of this situation,an evaluation method of bridge expansion joint based on GA-AHP is proposed.The specific research results are as follows:(1)The service condition of 345 bridge expansion joint in 7 districts and counties of Fu Yang city,Anhui province was investigated.According to the specification,the structural characteristics and working principle of the bridge expansion joint,it is divided into 4categories and 6 subcategories.The structural characteristics of each type of expansion joint are introduced and the main damage parts and damage process of each type of expansion joint are summarized.Moreover,the damage mechanism is analyzed and studied.(2)By the comprehensive application of analytic hierarchy process(AHP),genetic algorithm and other mathematical methods,a method for calculating the weight of bridge expansion joint based on GA-AHP is proposed.Considering the influence factors such as the function of bridge expansion joint,the comprehensive evaluation formula and assessment method of damage condition of bridge expansion joint are put forward.The standardized evaluation process and the evaluation standard of each type of bridge expansion joint are established.(3)The comprehensive evaluation method of bridge expansion joint is established.Firstly,the expansion joint device is classified according to the classification criteria,and its main components are determined.Then,according to the damage status of each component,the deduction value confirmation,the weight value of each component,the influence coefficient of traffic volume and the structural characteristic coefficient,the comprehensive evaluation value of the expansion joint is acquire by calculation,in which the scoring value of each component and the weight of each component are substituted into the comprehensive evaluation formula.Finally,the conservation strategy is determined by the evaluation value.(4)The method is verified by several examples,and the practice has proven that the evaluation method has strong operability and accuracy,which can provide suggestions and guidance for the maintenance of bridge expansion joints.