Seismic performance comparison of precast segmental bridge girders with different cross sections and boundary conditions under vertical quasi-static cyclic testing: An experimental investigation

In this study, five 1/5-scale bridge girder specimens are tested with vertical quasi-static cyclic loading, in order to understand their performance in high seismic zones. The study is focused on the superstructures at two critical regions: (1) close to mid-span where high moments and low shears are present (2) and close to the supports where high negative moments and high shears are induced. The first case includes one precast segmental bridge box-girder, one precast segmental bridge I-girder, and one reference cast-in-place I-girder, while the second case consists of one precast segmental bridge I-girder and one cast-in-place I-girder. The ratios of the internal and external tendons are 1:1 for case 1 and 3:5 for case 2, respectively. Test results show that cast-in-place girders have better energy dissipation capacity and higher ultimate strength, but the precast segmental girders retain larger displacement capacity and self-centering capability. Internal post-tensioning tendons are subjected to more significant stress concentration at the joint locations of the precast segmental girders, while stress of external tendons is distributed more evenly. In terms of vertical loading, box-girder and I-girder possess similar hysteretic behaviors, as long as the effective widths are the same.