A risk-based robustness evaluation of a prestressed concrete bridge

Existing bridges were designed to satisfy old specifications, and most of them were based on a member-oriented approach. A bridge superstructure is constituted by a group of elements that together form a system, and depending on how robust the system is, a member-oriented approach losses accuracy. Therefore, in this study a preliminary framework of how to assess concrete bridges' robustness is presented. The framework integrates a metamodel-based reliability analysis, and the risk concepts to evaluate the robustness level for concrete bridges considering failure probabilities and consequences. A case study of a prestressed multi-beam concrete bridge is used to validate and illustrate the methodology. The capacity of the individual elements, as well as of the intact and damaged structural system are calculated using finite element modeling (FEM). It was concluded that the framework proposed can be used to assess structural robustness with low computational cost, for the cases in which FEM is implemented.