Seismic Performance of Steel Concentrically Braced Frames in Australia: a Case Study

Abstract

The current Standard for determination of design earthquake forces in Australia, AS1170.4, prescribes a Structural Response Factor (R) of magnitude five for steel Concentrically Braced Frames (CBFs). This implies that during a design seismic event, CBFs designed in accordance with the Australian Steel Structures Standard AS4100 and typical Australian practice, will possess a level of ductility and overstrength sufficient to reduce the design level earthquake forces to one-fifth of those induced if the structure were to remain elastic. However, the requirements of AS4100 for connection design stipulate the brace design load rather than the brace capacity in the majority of CBFs. As a result, ..