Performance-Based Wind Design Methodology for Cable-Supported Bridges

Abstract

ASCE is moving to performance-based wind design (PBWD) for buildings, where the performance objectives are explained and the buildings to be designed are required to satisfy selected performance levels when subjected to selected design loading events. To explore the benefits of the PBWD methodology for cable-supported bridges, the ASCE SEI Technical Committee on Cable-Supported Bridges created a Task Group on PBWD to conduct a feasibility study on its applications to wind-sensitive bridges and to potentially develop an implementation plan with several case studies. This study first reviewed the current prescriptive wind design requirements in North America. Then, a survey was undertaken to collect opinions and perspectives from industry practitioners on PBWD for cable-supported bridges. Motivated by the positive response of the survey, a preliminary framework of a PBWD for cable-supported bridges, including performance objectives and acceptance criteria as well as bridge modeling and response evaluations (with both linear and nonlinear response history analyses), was established. Among the inherent benefits of moving from a prescriptive design approach to PBWD methodology is the allowance for inelastic behavior of selected bridge components (members) under extreme wind loading conditions. Hence, adopting the PBWD framework in cable-supported bridge design is expected to provide both economic and sustainable benefits.