Guidelines: Seismic Design of Composite Reinforced Concrete and Steel Buildings

Abstract

Seismic design guidelines for composite reinforced concrete and steel ~RCS! buildings consisting of reinforced concrete columns and structural steel beams were proposed in Japan as a practical outcome of the U.S.-Japan Cooperative Earthquake Research Program on Composite and Hybrid Structures. A design method satisfying the most prevalent seismic provisions used in Japan, which are based on the working stress design method, is described. At the same time, an alternative method, which is suitable for use in the context of the capacity spectrum method, is also briefly introduced. This paper outlines the design guidelines, giving priority to an explanation of the design method for the working stress seismic provisions. In this method, the weak beam-strong column mechanism is used as the design basis for buildings under severe earthquake. Therefore, moment magnification factors for both columns and joint panels are provided to secure the mechanism. Design equations for the ultimate shear strength of joint panels and associated hysteresis models are also included in the guidelines, and can be applied to a total of twelve details of RCS beam-column joints, including both the through beam and the through column types.