Study On Isolated Seismic Of Negative Stiffness Device In Continuous Girder Bridge

Concrete girder bridge under earthquakes is often destruction, due to the quality of the upper structure too large and acceleration to lead to large forces, the force passed to all piers and abutments by bearing, leading to cracking of piers or destruction of the main beam displacement too large falling beam disasters. Negative stiffness device is the device that can change the structural rigidity of the device, by reducing the stiffness of the structure to achieve the purpose of reducing the acceleration structure. The negative stiffness reduces structural stiffness leading to bridge deck large displacement. In general, viscous dampers are effect in reducing the displacement of the bridge deck but are not very clear to reduce the shear of the piers and the acceleration of the bridge deck. The combined the negative stiffness and viscous damper reduces shear bottom of the pier of the bridge structure, main beam displacement and acceleration in some degree.In this paper, three-span continuous beam of constant section as engineering background, using SAP2000 finite element analysis software, installed negative stiffness device bridge is calculated and analyzed. By negative stiffness mounting position is different, compared to the seismic response of the installation under the program to determine the merits of the installation program. Then under negative stiffness and damper means joint action, to observe the seismic response of the bridge to pass through while comparing the effects of different damping coefficient on seismic response. And in contrast to the original model, installing only the negative stiffness device, installing only the viscous dampers, the negative stiffness device and viscous dampers joint action, observe seismic response of the bridge structure.The results show that: the end of the pier shear install negative stiffness means the bridge structure and the main beam acceleration has reduced to varying degrees, but the displacement of the main beams are likely to increase. By negative stiffness and viscous dampers used in combination can effectively reduce the main beam displacement of the bridge structure, and shear of bottom of the pier and acceleration of the main beam have also been reduces in some degree. Simultaneously on different ground motions, the damping effect of the bridge structures is identical, according to different site features to set the parameters of negative stiffness device in order to achieve the best results.