Isolation effect analysis of the bridge with the negative stiffness damping device

As the existing bridge bearing is imperfect, the new combination isolation device composed of the isolation rubber bearing and the negative stiffness damping (NSD) device is proposed. In addition, compared with that of the bridge structure with the common bridge bearing, the isolation effectiveness of the bridge structure with the NSD isolation device is discussed. Through the theoretical analysis of negative stiffness principle, the advantage of the NSD seismic isolation system is proposed. And then, the earthquake response of a four-span continuous isolated bridge in different sites is analyzed by time history analysis method. It´s shown that the NSD isolation device can reduce the earthquake response by above 40% compared with the rubber bearing isolation system; by 25% compared with the lead-rubber bearing seismic isolation system and has the environmental advantage; by about 20% compared with the rubber bearing seismic isolation system added viscous dampers. The NSD isolation device is suitable for the isolation of the structures in different sites.