Seismic Response of Base-isolated Dual-system Reinforced Concrete Buildings at a Near-fault Site

In high-rise reinforced concrete buildings, using base-isolating systems can increase the response of the structure. To overcome this problem, it is suggested to increase the stiffness of the building by utilizing lateral load-bearing systems such as shear walls. In the present study, the seismic response of fixed-base and lead-rubber bearing isolated dual-system reinforced concrete buildings has been compared using nonlinear time history analysis procedure according to the 2800 V4 standard and ASCE/SEI7-16 code provisions. For this purpose, 10, 15, and 20-story reinforced concrete buildings, in a similar and regular plan, with special moment frame and shear wall dual systems have been selected as a case study. A 20-story building has been considered as a tall building in this study. Results show that the response of the base-isolated structures including the mean, median, and 16% and 84% percentiles of drift ratio, floor acceleration, and base shear has a significant decrease compared to the fixed-base buildings according to the above-mentioned code provisions. Results indicate that base-isolated buildings with respect to fixe-based buildings, based on the ASCE / SEI 7-16 code compared with the 2800 V4 standard, maximum drift in the structures has a 23% more decrease and mean acceleration and base shear have an 11% more decrease. The results obtained in this study can be the basis for the development of the 2800 standard provisions to investigate the seismic response of base-isolated reinforced concrete structures at a near-fault site.