Shaking Table Tests and Simplified Analysis for Bridge with Base Isolators Consisting of PTFE Plates and Rubber Rings

Shaking table tests are carried out for a 1/4 scale bridge model base-isolated with sliding type bearings consisting of PTFE plates and rubber rings. Then a simplified 2-degrees of freedom (DOF's) model is developed for the earthquake response analysis of the base-isolated bridge. The sliding friction of the bearing is represented as a function of the sliding velocity for the analysis. Comparison with the shaking table test results indicates that the simplified model with 2-DOF's yields very resonable results for earthquake responses.