Time-dependent performance indicators of damaged bridge superstructures

The ability of a structure to survive an extreme event without collapse reduces in time due to deterioration processes. Therefore, in the lifetime management of structures and infrastructures, the resistance to sudden local damage has to be considered together with the effect of progressive deterioration. The aim of this paper is to present a framework for computation of time-dependent performance indicators of civil structures and infrastructures, with emphasis on bridges, including reliability, vulnerability, robustness and redundancy. A brief theoretical background and selected structural performance indicators regarding vulnerability, redundancy and robustness are presented. The approach is based on probabilistic performance assessment supported by finite element analysis and applied to an existing bridge. Time-variation of vulnerability, redundancy and robustness associated with various damage scenarios under uncertainty and the effects of several loading conditions on performance are investigated.