Bridge condition rating model using eigenvector approach and fuzzy logic

Abstract

An multiple-layer fuzzy assessment model is proposed in this paperto evaluate the situation of existing reinforced concrete (RC) bridgeson the base of eigenvector (priority vector) approach and fuzzy logic.The multi-attributive decision making (MADM) model based on a priorityvector of the constituent elements of the component and fuzzy operationsare adopted to give a more realistic condition rating of bridges.The capabilities of computer program developed based on the proposedmodel, which incorporates the specific advantages of prioritization,optimal interval based membership functions and Fuzzy Weighted Average(FWA) technique are demonstrated through a case study. Environmentaleffect is considered in the proposed model because its indicatorrole includes not only the deterioration degree of concrete itselfdue to environment load, but also the crisis of reinforcement corrosionand material damage under rigorous environment. The method of thepriority setting of relative importance between elements is an opensystem dependent on not only the experience of inspectors and expertsbut also the major reasons of concrete deterioration and reinforcementcorrosion. The proposed methodology would help decision makers andbridge engineers to make systematic judgment and formulate methodicalsteps toward retrofitting, rehabilitation, or demolition of a bridgein future years.