Pounding effects of movable bearing on seismic behaviors of continuous girder bridges
The continuous girder bridges are largely used in bridge construction, and they are usually composed of 3 and more than 3 spans. Considering the longitudinal deformation of girder caused by temperature, shrinkage and creep of concrete, tension of tendons in girder and other factors, only one pier using fixed bearing (called fixed pier) can be adopted in one continuous girder bridge with normal pier height. So the fixed pier will bear very large force and be severely destroyed or collapse under strong earthquake. For continuous girder bridge with span of 20-40m and pier height of about 5m, the fixed pier can bear the moderate earthquake on its self. Under strong earthquake, large plastic displacement occurs in fixed pier. If the displacement of girder exceeds the gaps of movable bearing on the adjacent piers, the pier using movable bearing (called movable pier) can bear part of the longitudinal earthquake, which can avoid the fixed pier to be severely destroyed andmake the whole bridge safer.