Optimal strategies for highway bridge rehabilitation.

摘要

In this study, the cost effectiveness of bridge components' improvements is investigated both separately and in combination with all possible improvement alternatives. The study covers two subjects; (1) determination of the most cost effective improvement alternatives for a certain bridge replacement age; and (2) and comparison of the most cost-effective improvement alternatives for a range of different bridge lives to find the optimum bridge life.; To achieve the goal of the study; (1) a deterioration model is established to predict the performance of the bridge components and; (2) a cost model is established to determine the costs of improvement for each condition rating. Based these two models, the most cost effective improvement timing is searched for each components, both separately and in combination with others for a series predefined bridge lives by conducting incremental cost benefit analysis. The outcome of the search is a series of most cost effective improvement schedules for a range of different bridge service lives. The optimum life is obtained by comparing the most cost effective improvement schedules of every different bridge lives. The methodology is also applied to a specific bridge in the network to investigate the most cost effective improvement timing and the optimum bridge life.