Seismic response of fixed-base and LRB base-isolated RC framesystems under NF and FF excitations

Seismic isolation systems can be used in new structures to reduce the negative effects of the earthquake on the building. The lead rubber bearing (LRB) is one of the most commonly used seismic isolators. This study focused on the behavior of Reinforced Concrete (RC) frame systems with fixed-base and Lead Rubber Bearing systems under Near-Fault (NF) and Far-Fault (FF) records. For this purpose, two-plane frame systems with 4 and 8 story were designed. Nonlinear behavior of both superstructure and isolation system was taken into consideration in modeling. The nonlinear time history analysis method was used in the seismic analysis of reinforced concrete frame systems. Finally, story acceleration, interstory drift ratio, base shear force and distribution of plastic hinges and their damage conditions were evaluated. The results of the analysis showed that the effects of the NF earthquake record on the frame system had generally greater according to the effects of the FF earthquake records.