Cross-Sectional Compactness and Bracing Requirements for HPS483W Girders

Abstract

An evaluation as to the appropriateness of using the current American building and bridge specification (according to AASHTO 1998 and AISC 1999) provisions for cross-sectional compactness and adequate bracing is carried out within the context of flexural applications involving A709 Gr. HPS483W high performance steel I-shaped girders. It is observed from the current research that when HPS483W beams are proportioned and braced so as to satisfy the current AISC and AASHTO flange compactness, web compactness, and bracing provisions, less than half of the required flexural ductility is available to accommodate inelastic force redistribution in structural systems. As a result, new flange and web compactness criteria, as well as new bracing criteria, are proposed in the present paper for use in the design of A709 Gr. HPS483W I-shaped beams.