关键词: 桥梁工程, 简支梁桥, 抗震设计, 桥梁震害, 震害机理

Abstract: Study on damage mechanism of bridge is the important procedure which turns seismic damage investigation results into a practical technology. Some damage features of simply supported beam bridges which differ from the features in other earthquakes are shown in Wenchuan earthquake. The damage mechanism of pier and girder was simulated by FEM analysis and seismic table test. The results show that the seismic action of girder released by relative sliding between girder and bearing is why the damage of pier is reduced in Wenchuan earthquake. The displacement of girder is coordinated by continuous pavement , and the longitudinal displac&lnent is restrained by abutment , which reduces the risk of girder fell down. A complete seismic resistance system is formed by girder, pier, bearings , abutment , continuous pavement in simply supported beam bridges; the seismic action of girder is released and the risk of girder fell down is reduced by the system.

Key words: bridge engineering, simply supported beam bridges, design of seismic resistance, seismic damage of bridges , damage mechanism