Example of application of response history analysis for seismically isolated curved bridges on drilled shaft with springs representing soil

The main objective of this study is to perform a parametrical study associated with the effects of the earthquake ground motions on the seismic response of isolated curved bridges including soil-structure interaction. For the isolated bridge system, double concave friction pendulum bearings are placed between the deck and the piers, the abutments as isolation devices. A curved bridge is selected to exhibit the application for seismic isolation. The bridge is to be modeled and analyzed in a seismic zone with an acceleration coefficient of 0.7. g. The configuration of the bridge is a three-span, cast-in-place concrete box girder superstructure supported on reinforced concrete columns found on drilled shafts and on integral abutments founded on steel pipe piles. The bridge is located on site underlain by a deep deposit of cohesionless material. The drilled shaft-soil system is modeled by equivalent soil springs method, and is included in the finite element model. The soil is modeled as a series of springs connected to the drilled shaft at even intervals. The reduction of the internal forces on the deck for the isolated curved bridge is observed, if the forces are compared with those obtained for the non-isolated curved bridge.