Research Of Existing Arch-bridge On Comprehensive Evaluation About Reliability And Optimum Selection About Reinforcement Schemes

Lacks of carrying capability, material aging and damages in the existing bridges have been noticed all over the world. Relevantly servicing, evaluation and reconstruction for existing bridges have become the focus in the engineering field. A large proportion of bridges in china are Arch bridges, and the arch bridges' distributing are also wide. For assuring transportation safety, having the existing arch bridges to be used sufficiently, it is necessary to do proper reliability evaluation for the arch bridges. The reliability evaluation is both the preceding work and the key procedure of the maintenance and reinforcement of the existing arch bridges. According to results of the comprehensive evaluation, it can be decided whether the structure needs maintenance and reinforcement or not, then select reasonable choice of reinforcement schemes in numerous schemes. The thesis has set up the fundamental framework of multilevel fuzzy comprehensive judgment about evaluation and optimum selection of arch bridge's reinforcement based on analytical hierarchy process (AHP), so the difficulty of the determination of the weight of each factor can be overcome.Comprehensive evaluation about reliability and reasonable choice of reinforcement schemes both are important in the researching of the existing arch bridges. The research can be given reference to the scientific management of the existing arch bridges, and it has large economical benefits and broad future in practical engineering. Based on summarizing domestic and foreign results about the reliability comprehensive evaluation of existing bridges, more research on the comprehensive evaluation of concrete arch bridge has been accomplished in this thesis. The main contents in this thesis are as follows:1. The essence and character of the comprehensive evaluation about reliability of existing arch bridge is expounded. The status of domestic and foreign research on evaluation of existing bridge in has been summarized and reviewed.2. Expounded the basic principle of analytical hierarchy process and fuzzy comprehensive judgment, set up the whole and local fundamental framework of multilevel fuzzy comprehensive evaluation of arch bridge based on analytical hierarchy process (AHP).3. The selection and design about existing arch bridge and reinforcing scheme has much effect on reinforcing projects' quality. Many complicated factors which influence the effect of the reinforcement and the basic principle of select optimum methods are analyzed, and the two-level multilevel fuzzy comprehensive decision system is established.4. Summarize the conventional methods of reinforcement including their ranges in point about above of arch bridge.5. Utilizing the results of comprehensive evaluation about reliability of arch bridge, the paper set up evaluation-reinforcement integrity multilevel fuzzy comprehensive decision framework along with a practical double arch bridge's examples, so as to the scheme of reinforcement is reliable.