Evaluation on technical status of concrete cable-stayed bridge based on improved FAHP

Abstract

Because of the large number of components and complex evaluation indexes of long-span bridges, it is necessary to adopt the evaluation method suitable for complex structures. Since the hypothetical membership degree of fuzzy theory and the layer weight of traditional analytic hierarchy process (AHP) may have subjective bias, the evaluation precision may be influenced if it is applied independently in bridge evaluation and thus the fuzzy analytic hierarchy process (FAHP) is more applicable to large-span concrete cable-stayed bridge. The traditional analytic hierarchy process using triangular fuzzy number (FAHP) has the shortcomings of computational errors and limited range, so the improved FAHP is adopted. The improved FAHP method introduces the reliability into the judgment matrix, which can not only solve the existing problems, but also reflect the influence of the fuzziness of the man-made subjective judgment on the result. Based on the detection results for a concrete cable-stayed bridge in Jilin Province, the corresponding hierarchy of index system is established, the trapezoidal function is used to calculate membership degree, and the weight of each index relative to target layer is calculated. Improved FAHP is finally applied to assess the security levels of various parts of this bridge and make comprehensive evaluation on the whole bridge.