An Investigation on DDBD Approach of Near-Fault RC Frame, RC Wall-Frame and Steel Braced RC Frame Systems

Direct Displacement Based Design (DDBD) is one of the novel approaches for structural design of reinforced concrete frame systems. In this study, DDBD approach is investigated for single momentresisting reinforced concrete frame, dual reinforced concrete wall-frame and dual steel braced reinforced concrete frame systems. In this methodology, first the displacement profile is calculated, following which the equivalent single degree of freedom system is modeled considering the damping characteristics of each member. Then, having calculated the effective period and secant stiffness of the structure, the baseshear is obtained based on which the design process can be carried out. For each system three frames are designed using Direct Displacement Based Design approach. The frames are then analyzed using nonlinear time-history analysis with 7 near-field earthquake accelerograms. In order to reach an understanding of response of the three systems designed using Direct Displacement Based Design, damage index is investigated through lateral drift profile of the models. Compatibility of the above mentioned systems with Direct Displacement Based Design approach is also studied via comparison of the nonlinear time-history analysis results. The results of the analyses indicate efficiency of the DDBD approach for different reinforced concrete structural systems located in near-field regions.

Keywords:

Direct Displacement Based Design , RC frame systems , Time-history analysis , Near-field accelerograms