Seismic Design, Analysis and Testing of a Friction Steel Braced Frame System for Multi-Storey Buildings in Vancouver

Abstract

This article describes the application of the Friction Braced Frames (FBF) system for 4-and 10-storey buildings located in Vancouver, BC, in Canada. The FBF is coupled with a secondary moment resisting frame that provides back-up elastic stiffness and re-centring capacity that contribute to reduce storey drifts and more evenly distribute seismic energy dissipation over the frame height. In this study, the energy dissipation components consist of Pall friction devices and the system was designed using a conventional force-based method. The moment frame was proportioned to remain essentially elastic under the design seismic displacements. The seismic response of the system is examined through nonlinear response history dynamic analysis. An exhaustive test program was developed to verify the capacity of the system to sustain the anticipated seismic demand. Full-scale testing was performed on brace sub-assemblages and individual brace specimens equipped with friction elements. The experimental program included full-scale dynamic testing under real-time seismic displacement histories as obtained from response history analysis. The numerical simulations and test program showed that the dual FBF system represents an effective system for enhanced seismic response of multi-storey building applications in high seismic regions.