关键词: 桥梁工程, 限位墩, 伸缩缝, 碰撞, 最大墩梁相对位移, 最大墩底弯矩

Abstract: Practice and experience in engineering shows that restrainer piers can greatly reduce the occurrence of collapse of long bridge，while the size of expansion joints at the restrainer piers top can affect the longitudinal seismic performance of long bridge tremendously. Consequently，the effect of expansion joint spacing on the dynamic response of long bridge under the action of the longitudinal seismic was analyzed by means of finite element analysis. Researches show that with the increase of the spacing，the main beam does not appear collision and the impact force does not show a downward trend. The maximum bending moment of the ordinary pier bottom does not show a particularly obvious law; however，the maximum pier bottom bending moment of the restrainer pier is mainly affected by the impact force，and the change of the maximum pier bottom bending moment is similar to the maximum impact force at the pier top. As a matter of fact，the maximum relative displacement between girder and pier，the maximum impact force as well as the maximum pier bottom bending moment of the ordinary pier do not make difference with the increase of the expansion joint spacing.

Key words: bridge engineering, restrainer pier, expansion joint, pounding, the maximum relative displacement between girder and pier, the maximum bending moment of the pier bottom