Abstract:

With the rapid development of demands for transportation, highway bridges are under much heavy operating load that overruns the design standards, which results in fast degradation of the highway bridges completed in 1990＇s. In order to make the best use of the limited funds for bridge maintenance, an improved model is represented to optimize the maintenance strategy of bridges. This model uses the ＂expected life＂ as the optimization objective instead of various performance indices, and combines the optimization objective with the conventional objective ＂cost＂ to construct a bi-objective optimization problem. In this model, the difference in the performance and the degradation rate at the end of the horizon period in different strategies is considered, and the demands for various performance indices are unified as the objective ＂expected life＂. The authors also introduce two efficiency indices, namely the ＂life per cost＂ and the ＂cost per year＂ for the decision of maintenance strategy. Several examples are finally presented based on the data of highway bridge components.

Key words: bridge, maintenance strategy, optimization, residual life, cost, last degradation rate