Seismic response of multi-span highway bridge: Effectiveness of using isolation system

Seismic response of isolated bridge under several earthquake ground motions is presented in this paper. Non-linear time history analysis is carried out for both non-isolated and seismically isolated bridge. Lead rubber bearing is employed to observe the isolated bridge behavior. Takeda trilinear model is used to model the mechanical behavior of the pier and simple elastic model is applied to model remaining portion of the bridge. Four different earthquake ground motions are considered and applied at the longitudinal direction of the bridge. It is found that the effectiveness of base isolation technique is highly influenced by the properties of the isolated bridge as well as by the ground motion. It is also revealed that to understand and design efficient isolated bridge system, analyzing the ground acceleration in frequency domain could be more efficient than time domain approach.