A multi-level asset management decision method considering the risk and value of bridges

Abstract

For efficient and rational utilization of limited bridge maintenance budgets, a method which could be applied to project-level and network-level bridge maintenance decision making issues considering the performance and direct and indirect value of each bridge is proposed. A representative bridge performance is shown as a risk level which is a combination of risk degrees indicated by condition state and safety factor and the replacement value was calculated by considering the direct construction cost and implicit value of bridges in consideration of traffic environments according to the location. The risk matrix was composed using the risk level and the replacement value, and the risk grade which represented the overall risk of each bridge was defined. The model to convert the phased risk level of each bridge to the risk index which was the continuous and quantitative index by applying the utility theory was presented, and the formalized model for calculating network-level performance index considering the risk index and relative importance of each bridge was suggested. In order to consider actual applicability of the suggested method, an analysis on a large number of actual bridges was carried out. A prior preparation regarding the stable distribution of budget and structural and environmental risks is possible so that it would be possible to quantify objective decision making for bridge maintenance.