Decision-making of railway bridge reinforcement and reconstruction scheme based on PCA and improved TOPSIS

In order to reduce the potential risks in the reinforcement and reconstruction process of railway bridges in China, and considering the shortcomings of the existing decision-making methods, this paper established a scientific decision index system according to the characteristics of the problem, and proposed a decision-making model based on principal component analysis (PCA) and improved TOPSIS method of weighted generalized Mahalanobis distance. Firstly, the triangular fuzzy function is used to quantify the qualitative indexes, then the weight of each index is calculated by the entropy weight method. And using the PCA method to reduce the index dimension according to the contribution rate of the cumulative variance of the index. Secondly, using the improved TOPSIS method of weighted generalized Mahalanobis distance to calculate the distance between each index scheme and the positive and negative ideal solutions. Finally, five engineering examples are given to verify the credibility and superiority of this method. The selected scheme can meet the requirements of performance improvement and economic rationality to the greatest extent. © 2020, Central South University Press. All rights reserved.