Research On The Method Of Optimum Selection Of Reinforcement Scheme For Prestressed Concrete Continuous Beam Bridge

With the rapid development of highway transportation,continuous girder bridges are seriously degraded under the influence of traffic volume and environment.The important responsibility of managers is to select the optimal reinforcement plan to minimize the expected loss.The current optimization technology rarely takes into account the one-sidedness of the weighting method,the credibility of the scheme and the exclusive assumption of the evidence theory.In view of the above problems,the main research work of this thesis is as follows:1.Summarize the related diseases and treatment measures of the prestressed concrete continuous beam bridge,and analyze the characteristics and applicability of various reinforcement methods for the upper structure,lower structure and bridge deck system of the prestressed concrete continuous beam bridge.It is a prestressed concrete continuous beam Provide a basis for the design of the bridge reinforcement scheme.2.Establish an evaluation index system for reinforcement schemes of prestressed concrete continuous beam bridges.Define the mathematical formulas of 11 quantitative indicators and the quantitative methods of 8 qualitative indicators.3.On the basis of analyzing the lack of current weighting methods and optimization methods,the optimization method of prestressed concrete continuous beam bridge reinforcement scheme based on Hellinger distance and Pignistic angle is proposed.1)In order to overcome the one-sidedness of the single weighting method and the shortcomings of the current combination weighting method,a combination weighting model based on Hellinger distance and Pignistic perspective is proposed.The group AHP method,the entropy weight method and the coefficient of variation method are the single weighting method basis of the combined weighting model.In order to solve the problem of inconsistency in the weighting of the group AHP method,it is proposed to construct an expert entropy model to determine the objective weight of the expert,integrate the subjective and objective weight of the expert to obtain the expert weight,and combine the indicator weight matrix under the expert group to determine the subjective weight of the indicator;2)Aiming at the limitation of the exclusive hypothesis of evidence theory,proposed a reinforcement plan optimization model based on Hellinger distance and Pignistic angle to improve the evidence combination;3)Grey correlation method to determine the basic probability distribution function(BPA),and then use the new evidence combination model in 2)Fuse the evidence body,obtain the trust function,and rank the schemes accordingly.4.Relying on the maintenance and reinforcement of the Hanzhuang Bridge in the emergency water supply project of the Beijing-Shijiazhuang section of the middle route of the South-to-North Water Transfer Project,the feasibility of the optimization technology of the prestressed concrete continuous beam bridge reinforcement scheme proposed in this paper is verified.The comparison with the single weighting method shows that the proposed combined weight model based on Hellinger distance and Pignistic angle is more scientific and reasonable.Through the calculation process of the reinforcement scheme optimization model,it is shown that the overall uncertainty of the reinforcement scheme selection result of the method in this paper is reduced from the average value of 12.11% to 0,which greatly improves the accuracy and persuasiveness of the reinforcement decision-making.Through the comparative analysis of the method in this paper and the analytic hierarchy process,the grey correlation method and the evidence theory,the superiority of this method in the Optimum Selection of bridge reinforcement schemes is further verified.