Quality State Evaluation Research Of The Concrete Bridge In Service

As time goes on, existing bridges are functionally obsolete and aging and suffer accumulatively serious structural damage. It has become difficult for them to adapt to the still growing traffic volume. They have become the bottleneck to transportation, restricting the rapid development of China's economic construction. Even some bridges have collapsed, resulting in huge losses to people's lives and property safety. Therefore, in order to ensure the smooth traffic of highways and create safe and comfortable driving environment, regarding how to make reasonable and accurate assessment of existing bridges, it has become the focus in the engineering field.In this dissertation, existing highway bridges were research objects. The status of existing bridges at home and abroad and bridge evaluation was analyzed, and the urgency and necessity of evaluating the status of existing bridges were pointed out.Fuzzy set theory and fuzzy comprehensive evaluation theory were elaborated and summarized. The methods and process of fuzzy comprehensive evaluation applied to bridge structure were also introduced.According to characteristics and damage features of bridge structure, bridge structure was divided into layers and several subsystems, and bottom evaluation indicators of each subsystem were determined, the fuzzy comprehensive evaluation hierarchical model of bridge structure was established, evaluation standards of bottom indicators were also given by combining specifications and related literature, and evaluation set vectors V={v₁,v₂,v₃,v₄,v₅} which were consistent with specifications were determined.Indicator weight of each bridge layer was determined by Analytic hierarchy process?AHP?. Compared each layer of indicators in pairs by the method of any interpolation among 1⁹. The judgment matrix has good consistency. Reasonable weight distribution has been obtained by calculating the characteristic vector of the maximum characteristic value.The load test of Baoping Bridge?was analyzed and summarized, conventional comprehensive evaluation and fuzzy comprehensive evaluation of this bridge based on bridge inspection and test results were also carried out. The final score by conventional comprehensive evaluation is Dr=60.4, so it is a bridge of the second type; fuzzy evaluation set of this bridge is?0.140, 0.293, 0.376, 0.171, 0.020?, and then this bridge is in a quite poor state of the third type according to the maximum membership principle and weighted-average method. Results by both evaluation methods have been don't consistent, proving the applicability and effectiveness of fuzzy comprehensive evaluation method for bridge structure in this dissertation.