Seismic response control of benchmark highway bridge using passive hybrid control systems

In this study, the seismic response of a benchmark highway bridge is investigated with passive hybrid systems consisting of high damping rubber bearing (HDRB) and linear and nonlinear viscous fluid damper (VFD). The Phase I problem of the benchmark highway bridge is considered for this study. The ground acceleration is applied at all supports of the bridge. A comparative study is performed among the passive control strategies for seismic response control of the highway bridge by calculating various evaluation criteria as mentioned in the benchmark highway bridge problem. A parametric study has been conducted to find different parameters of VFD and HDRB. The optimum damping coefficient and velocity exponent are found for VFD and optimum isolation time period and optimum damping ratio are found for HDRB. The passive hybrid control system consisting of HDRB and nonlinear VFD gives better performance for reduction of base shear, overturning moment, displacement at midspan, bearing deformation and displacement at abutment of the bridge. Hence, it can be deduced that the performance of passive hybrid control system consisting of HDRB and nonlinear VFD is better than individual VFD and HDRB control systems.