Safety Evaluation For CFST Arch Bridge Based On Uncertain AHP

Long-span bridges are the hinges of traffic system and play an important role in national economic and society.With the span increasing,the research of the safety of long-span bridge has become the focus of bridge engineering.The necessity of establishing the safety evaluation system of bridges doubtless has good social and economic performance,which can discover the degeneration of bridges and avoid the occurrence of the disastrous bridge accidents.In this paper.based on previous research work, the current synthetic method is further improved,and a corresponding program of evaluation of the state for CFST arch bridge is worked out.This program will be implemented in the fifth Jianghan Bridge in Wuhan,China. The concrete research result is as follows:Chapter 1 depicts the state-of-the-art of safety evaluation for bridges in detail,predicts the development trend of the bridge safety evaluation and introduces the content of this dissertation concisely .In chapter 2,based on the deficiencies of the traditional the analytic hierarchy process (AHP) methods,the Uncertain AHP methods and the corresponding method of calculation weights is introduced because of the uncertainty and fuzziness of bridge evaluation .In chapter 3,the group decision-making is applied in the safety evaluation,and the credit degree is put forward to considering the experts' appraisal level.The principle of Set-valued Statistics and the fuzzy gravity Center based decision theory are put into a new method,and are applied in the uncertain type of AHP.Hence,the weights of evaluation indices that reflect the experts' level are gained.This measure,which reflects the objective of the evaluation process and the subjective of the experts,can concentrate various opinions and lower the deviation of the evaluation process.A new method of calculating weights and variable weight is presented in the safety evaluation,and it isdiscussed that how the method of variable weight is applied in several evaluationmethods.In chapter 4,the synthetic evaluation method is proved feasible and practical through being applied to the practical bridge and reflects the safety status of the fifth Jianghan Bridge.The author sets up a safety evaluation model of CFST arch bridge and discusses that how the method of the synthetic evaluation method is applied in the existing bridge in detail.At the same time a variable weight is presented in the safety evaluation.The main contribution and conclusion of this dissertation is summarized in chapter 5.Some relevant problems desired further studied are also presented.Now the safety evaluation of bridge is becoming the focus problem in the research of bridge engineering.The main purpose of this paper is the study of the safety evaluation methods for bridges.In the evaluation field of safety of bridges,there are still mang morks need to be further studied,for example :how to define the characteristic indices and grade standards , how to determine the weights of indices in economic analytic methods.