Overview
Current assessment code BD21/97 only accounts for element failures in bridge assessment.
However, in many cases, element failures may not cause system failures. In other words, a bridge may have lower chances of failure than the assessed value when system failure is considered.
In order to utilise the scarce resources effectively for bridge maintenance, the authorities need to take into account both element and systems risks.
The main objective of this research is to develop a methodology for evaluating reliability-based minimum acceptable criteria for bridge performance, at an element and at a system level.
A failure-consequence-based approach has been adopted to measure bridge safety in terms of the risk level rather than the conventional failure probability level. Several case studies have been performed using the response surface method and the consequences models.
The results obtained will be used as the basis for proposing modifications of target reliability levels to account for element-system effects, and also for drafting an efficient framework/strategy for bridge management.