Determining the Optimal Weight of Uncertain Hierarchy Analysis in Bridge State Assessment

Bridge evaluation has become more and more important in recent years and the key of it is to ascertain the index weight objectively. Although the uncertain hierarchy analysis can reflect the uncertainty and fuzziness of the assessment, the region weight can not be used directly to assess the bridge state. In this paper, a new method based on the principle of deviation degree was proposed to calculate the indexes weight, which is used to set up an objective optimized model for the unknown indexes weight among the judgment matrix of uncertain hierarchy analysis. Then, the optimal model was transformed to the nonrestrictive optimal function by the approach of real genetic algorithm (RGA). The result of the indexes optimal weights were obtained by the operation of copy, chiasm and aberrance to global optimal search. At last, two examples were employed to test the validity of the proposed method. According to the uncertain judgment of the indexes, some different methods were carried out and the calculated data were analyzed and compared. The results verified the feasibility of the new method presented in this study.