ABSTRACT
Bridge managers estimate intervention requirements years in advance. They do this to help ensure that work that needs to be carried out can be planned appropriately in terms of quality and timing. These initial estimates must be done at least 10 years before an intervention is required and perhaps even up to 20 years. These large time periods are required so that detailed investigations can be carried out, decisions can be made as to what should be done, work sites can be planned that exploit synergies between multiple interventions, that intervals can be built into train schedules so that there is enough time to do the work, and then the construction sites can be planned in detail. This paper proposes a methodology to be used by bridge managers to obtain a consistent and complete overview of these future bridge interventions and give indications of the required possession windows required in train schedules, and the approximate costs. The methodology is an improvement on the existing bridge management system methodologies in that it uses nonhomogeneous transition probabilities, instead of homogeneous ones, and explicitly estimates the risks associated with different types of bridge failure as a function of the condition states of the different structural components. Existing methodologies do not explicitly consider failure risk in this manner. The methodology is demonstrated using a 100m-long steel truss bridge in Switzerland. The results are visualized using BIM, which allows bridge managers to better understand the algorithmic results and facilitates discussions between multiple stakeholders of the planning process to prioritize interventions. The use of the methodology is expected to improve both effectiveness and efficiency of the intervention planning process.
