Risk-based bridge management

This paper outlines a methodology for bridge project selection based on reliability methods and optimization procedures, which could serve as part of a bridge management system. The Markovian model is used to decay the structural components. Then, a reliability index is determined for each element using either subjective assessment or first-order reliability methods. The overall reliability of the bridge is calculated as a system reliability by combining the individual reliability of the components in a series system. Risk is obtained from the reliability of the bridge and the consequence of closure. Repairs can be modeled in any year. The optimum set of repairs is defined as that which minimizes the total network risk in the planning horizon. Methods for finding the optimum set of repairs are discussed, and a near-optimum algorithm is selected.