Shaking table tests of base-isolated reinforced concrete frame by double friction pendulum bearings

Abstract

The effectiveness of seismic isolation by friction pendulum bearings (FPBs) in protecting structural and non-structural components from damage was evaluated by shaking table tests. A base-isolated reinforced concrete frame model by double friction pendulum bearings (DFPBs) with 1/5 scale was considered in the experimental program. A non-isolated model was also tested for comparison. The models were subjected to ground motions with incremental earthquake intensities. This paper presents a comprehensive overview of the test results in terms of peak inter-story drifts, peak floor accelerations, floor acceleration response spectra, hysteretic behaviors, seismic responses of the DFPBs and damage mechanisms of the structures. The results demonstrated that the base-isolated system can effectively protect both structural and non-structural components even under earthquakes larger than maximum considered intensities. The residual displacements of DFPBs remained small after multiple inputs and showed no direct correlation with the maximum sliding displacement and earthquake intensities. The effects of vertical earthquake shaking on the displacement responses of DFPBs were negligible for the test model.