CRITICAL DISCUSSION ON SEISMIC DESIGN CRITERIA FOR CROSS CONCENTRICALLY BRACED FRAMES

Recent studies show that the application of EC8 design procedure for X-CBFs, leads to uneconomical and ineffective structural systems, characterized by massive structural members, large lateral overstrength and poor plastic engagement. In this paper, the EC8-compliant design procedure is summarized and critically discussed also comparing the EC8 detailing rules with those recommended in US Code. In order to assess the influence of the different codified requirements, a six-storey residential building is selected as benchmark case and alternatively designed according to both European and US code. Nonlinear dynamic analyses are performed and the seismic performances of EC8 and AISC-compliant frames are discussed and compared.