Durability Evaluation Method of Reinforced Concrete Beam Bridge Based on Extension Interval Number Theory

In this paper,a method for evaluating the durability of reinforced concrete simple supported beam bridge was proposed based on the extension interval number theory and analytic hierarchy process. Firstly, the multi-layer durability evaluation model of simply supported beam bridge is established, which includes sub index layer, index layer, project layer and target layer. Then, the interval number of extension theory is used to replace the number of points to construct the judgment matrix in the model, which solves the fuzzy and uncertainty problems of the traditional AHP expert experience judgment. Due to the uncertainty of the factors affecting the bridge, the normal correlation function is constructed, and the correlation degree of each evaluation element to each grade is used as the basis for the quantitative evaluation of the bridge. Each layer is evaluated based on the results of the following assessment. The bridge durability can be obtained through the level by level evaluation. Finally, an example of a beam in Chao-yang bridge is used to illustrate the method and process of evaluation. The results are reliable and applicable. The assessment process proved that the method presented here is an effective one to solve the paradox in bridge evaluation, where qualitative and quantitative coexistence takes place.