Seismic response control of long-span and super-long unit continuous girder bridges based on negative stiffness device
To improve the seismic isolation technology of long-span and super-long-unit continu-ous girder bridges,we proposed a novel seismic isolation system by introducing a negative stiff-ness device(NSD)into the bridge and compared it with the combined isolation system of viscous dampers and friction pendulum bearings.The finite-element model of the full bridge was estab-lished based on CSiBridge software.The NSD was simulated by an elastic multisegment line.The friction pendulum bearing and viscous damper were simulated using the bilinear restoring force model and Maxwell model,respectively.Nonlinear time-history analysis was conducted by input-ting three seismic waves to investigate the seismic response of the bridge under the novel seismic isolation system.Results show that NSD and viscous damper can effectively reduce the bearing displacement of the long-span and super-long unit continuous girder bridge.The NSD performs better than the viscous damper in terms of controlling the internal force response of the pier and the acceleration response of the beam.The NSD presents a good application prospect in the seis-mic response control of long-span and super-long unit continuous girder bridges.