Performance-Based Assessment and Structural Response of 20-Story SAC Building under Wind Hazards through Collapse

With the increasing occurrence of extreme wind events (e.g., hurricanes) and growing interest in performance-based wind engineering, a better understanding of the structural response and collapse under extreme wind loads is needed. Studying the inelastic nonlinear response of buildings through collapse under wind hazards can lead to safer structures and inform future economic designs. The objective of this paper is to investigate the performance of a 20-story steel moment-resisting frame, from the SAC project, under wind loads at different wind speeds. SAC is a joint venture between the Structural Engineers Association of California (SEAOC; the S in SAC), the Applied Technology Council (ATC; the A in SAC), and California Universities for Research in Earthquake Engineering (CUREe; the C in SAC). The building design was first assessed for compliance based on the latest code requirements. Next, a nonlinear dynamic analysis under three different hazard levels was used to conduct a performance-based assessment. The analysis showed that the building conservatively meets the different performance targets. The building was deliberately underdesigned, which resulted in an 18% reduction in used materials, to conduct a comparative nonlinear response analysis and performance-based assessment. The nonlinear analysis for both building designs was extended under increased wind loads through collapse. Overall, the different parts of the study confirm that current code methods can lead to overly conservative structural designs and suggest that incorporating a performance-based approach along with a well-controlled nonlinear response under extreme wind events can lead to safer and more economical designs and is worthy of further investigations. (C) 2020 American Society of Civil Engineers.

Automated summary

This paper investigates the performance of a 20-story steel moment-resisting frame under different wind speeds, showing that the building meets performance targets and was intentionally underdesigned. The study suggests that current code methods may lead to overly conservative designs and recommends incorporating performance-based approaches and controlled nonlinear responses for safer and more economical designs.