Performance Based Design of Reinforced Concrete Frames with Steel Bracing

This study investigates a direct displacement-based design (DDBD) procedure for dual system structures comprised of reinforced concrete frames and steel bracings. In this procedure, in order to establish the design displacement profile before any analysis, strength proportions between bracings and frames are assigned. Using the displacement profile and damping characteristics of the structural components, the structure can be represented as an equivalent single-degree of freedom system. The effective period and secant stiffness of the structure isthen calculated, and finally having computed the base shear, the design process can be implemented. 4-, 8- and 12-story structures have been designed using this methodology, and in order to validate it, 7 near-field accelerograms have been used for nonlinear time history analysis of the above structures. The results demonstrate the efficiency of this procedure for near field structures.

Keywords:

direct displacement-based design , effective period , design displacementprofile , equivalent single-degree of freedom system ,