Life-cycle performance assessment of highway bridges under multi-hazard conditions and environmental stressors.

摘要

Civil infrastructure systems such as highway transportation networks are tied up, directly or indirectly, with every country's economy in a major way. The state of nation's civil infrastructure has also significant impacts on the safety and quality of living. Among various infrastructure components, the highway bridges play a key role in a transportation network and huge money is spent every year to ensure their functionality. Over the time, highway bridges are aging, rapidly deteriorating, and becoming increasingly vulnerable to the catastrophic failure during probable natural or man-made hazards. In this study, the performance of reinforced concrete highway bridges, which form the majority of existing bridges in California, is evaluated during earthquake events while they have been continuously exposed to environmental stressors, such as attack of chloride ions. To assess the global structural degradation due to the deterioration mechanisms, an inventory of representative bridges of California with different structural attributes are studied. The extent of capacity loss is calculated using a finite difference procedure and the results are then utilized to find the life-cycle cost of bridges. The effects of deterioration processes on the functionality of the entire transportation network are also studied through the case-study analysis of the Los Angeles and Orange County highway transportation network. The change in the most important parameters associated with the network performance, such as total travel time, drivers delay, and traffic capacity, are thoroughly investigated following various bridge type-age scenarios. The inspection and maintenance costs of the whole system are then estimated using a multi-hazard framework to minimize the system costs while ensuring its safety.