Seismic control of benchmark cable-stayed bridge using passive hybrid systems

Earthquake response of benchmark cable-stayed bridge with passive hybrid control systems is investigated. The passive hybrid system consists of high damping rubber bearing, lead-rubber bearing, friction pendulum system and resilient-friction base isolator (R-FBI) supplemented with the linear and non-linear viscous fluid damper (VFD). Considering the phase-I benchmark problem, the ground acceleration is only applied in the longitudinal direction acting simultaneously at all supports. The seismic response of benchmark bridge is obtained by solving the governing equations of motion by Newmark's step-by-step integration method. A comparative performance study among the four hybrid control systems for seismic response control of bridge is carried out by finding the various evaluation criteria under different parameters of the hybrid control system. Significant reductions in the base shear, overturning moment and other responses (especially deck displacements) were observed by using the passive hybrid control systems. The optimum values of damping coefficient and velocity exponent of passive VFD and isolation time period of the isolation system was also investigated. The performance of passive hybrid control system consisting of R-FBI with non-linear passive VFD is found to be better in comparison with the other control strategies.