Research On Durability Evaluation And Prediction Of Concrete Beam Bridge Based On Extension Theory

With the increase of service life,the durability of concrete girder bridges will gradually decrease.In order to avoid the terrible consequences caused by durability failure,this paper starts with the evaluation index of durability,uses the entropy-weight extension theory to evaluate the durability of concrete beam bridges,and uses the extension theory and the analytic hierarchy process to realize the prediction of durability level of concrete beam bridges with different service life.Combining with the actual bridge,the durability evaluation and prediction results of this method are compared with the actual evaluation results,which verifies the feasibility of the evaluation and prediction method.The specific implementation process is as follows:Firstly,the basic principle of extenics is introduced,and the matter-element extension evaluation method can be applied to durability evaluation of concrete girder bridges.The advantages of extension evaluation method over other evaluation methods are analyzed.According to the existing norms and research results,the time-varying calculation model of durability evaluation index is selected,and the applicability of the calculation model is introduced.Secondly,the evaluation model is established based on the theory of entropy-weight extension,and the durability index evaluation system of superstructure of girder bridge is established on the basis of "Evaluation Criteria for Technical Conditions of Highway Bridges" and "Regulations for Testing and Evaluating Bearing Capacity of Highway Bridges",and the durability index grade evaluation criteria are determined,which enhances the scientificity of the evaluation.Taking a girder bridge in Shanxi Province as an example,the durability of its five-span superstructure is evaluated.The evaluation results are consistent with the actual situation,which shows the applicability of the entropy-weight extension method.Then,the evaluation model is established by using extension theory and analytic hierarchy process,and the time-varying model of evaluation index is established based on the existing research results.The time variable is introduced into the durability evaluation,so that the durability evaluation has the function of prediction.Taking a girder bridge in Shanxi Province as an example,the durability of the bridge is predicted.The predicted results of this paper are compared with the actual evaluation results,which verify the feasibility of this prediction method.Finally,using VB6.0 programming tool,the durability evaluation software of concrete beam bridge based on the entropy-weight extension theory(v1.0)is designed,and the visual operation interface is designed to facilitate the use of the software.The software runs smoothly,and the result of software running is basically consistent with the result of manual calculation,which proves the practicability of the software.