Recently, it has been considered in highway bridge codes that a large length gap between bridge girders may be better than a small size one in order to avoid the pounding phenomenon of. bridge girders. However, if a large length gap is adopted, expansion joints have to become large and the construction cost will increase. Gap reduction considered the pounding of bridge girder is one means to decease construction cost. In order to reduce gap length adjacent between bridge girders, it is firstly necessary that the grade of damage on the ends of bridge girders and the pier bottoms on pounding of adjacent bridge girders are grasped.
In this study, the gap reduction considered the pounding of bridge girders on PC bridge was attempted. The damage levels were taken into account with a view to the concrete stress of RC plate impacted by the horizontal impact test and the bridge pier bottom damage obtained by the relation between bending moment and curvature of RC pier section. Then, elastic-plastic seismic response analysis of a PC bridge was carried out by changing the size of gap and the magnitude of inputted earthquake level. The maximum dynamic response of bridge girders and bridge piers by elastic-plastic earthquake response analysis were compared with the introduced damage levels. The effects of gap reduction on damage of both the end of bridge girder and the pier bottom were examined, and the possibility of gap reduction on PC bridge was considered.