Seismic Vulnerability Evaluation of Axially Loaded Steel Built-up Laced Members

Keywords: Seismic vulnerability.  Built-up bracing members.  Seismic evaluation.  Hysteretic behavior.  Cyclic inelastic behavior.  Laced bracing.  Compressive strength.  AISC LRFD Specifications.

Abstract: The objective of this report’s research is to provide additional knowledge on the seismic behavior of laced or built-up braced members.  This study reviews historical design provisions and steel design textbooks published when laced bracing was commonly built, along with recent research work conducted for built-up bracing members.  A limited experimental program was designed and conducted to investigate the hysteretic behavior of typical built-up compression members, including design and quasi-static testing of the specimens.  The results of this study are discussed in a quantitative manner, including energy dissipation in compression and strength degradation of compressive members.  References are provided, along with numerous photographs, figures, and several appendices.