Control of nonlinear bridge response with pounding effect by variable dampers

Under strong ground excitations, highway bridges experience severe nonlinearity induced by inelastic deformation at plastic hinges of piers and pounding between two adjacent decks. To mitigate the nonlinear response of bridges, semi-active control was implemented using variable dampers. This research was conducted to investigate the effectiveness of variable dampers in improving the seismic response including pounding effect. It is found that the friction-type damping force scheme gives the largest reduction of deck displacement, relative displacement between two decks, and the flexural hysteretic curvature at the plastic hinge of a pier. Pulse-like acceleration response resulted from pounding between two decks is reduced extensively.