ABSTRACT
Current bridge design and assessment practices remain primarily focused on evaluating the strength and serviceability of individual structural members and components. While this traditional member oriented approach has led to the design of safe bridge infrastructure networks, it is widely recognized that the approach does not necessarily lead to an accurate evaluation of the actual structural safety levels nor to the efficient utilization of resources when making decisions related to the management of existing deteriorating structures given the limited funds currently available for rehabilitating and replacing our ageing bridge stock. For this reason, there is renewed interest in developing system-level assessment methods as a basis for modern bridge safety evaluation and design processes.
This paper reviews recent proposals for developing and implementing system performance criteria in bridge engineering. The paper addresses the establishment of performance-based design methods and structural redundancy and robustness metrics as well as network based ranking criteria. Insights from these reviews outline the benefits of transitioning bridge design and safety assessment processes from the traditional component-level approach to one that seeks uniform levels of risk for structural systems and infrastructure networks. Examples are presented to illustrate the implementation of these concepts in bridge engineering practice.
