Seismic Damage Evolution Simulation of Long-Span Deck Steel Truss Arch Bridge

To evaluate the damage state of a long-span steel arch bridge under multi-dimensional earthquake loadings, a deck steel truss arch bridge was studied. A bridge elastoplastic fiber element model was established by OpenSEES code. Two damage index, i.e., strain and two-parameter damage index were selected for damage evaluation. The damage assessment of both members and the whole bridge were obtained by incremental dynamic analysis (IDA). Moreover, the applicability of two damage index on the main members of the bridge (steel pipe, concrete-filled steel tube, and reinforced concrete member) was compared. The results show that the assessment result by the two-parameter damage index based on deformation and energy may lead to 1−2 damage assessment levels worse than by strain damage index. Less damage is caused when the identical earthquake loading is input in transverse direction than longitudinal direction. The full bridge is still in a slightly damaged state when the peak ground acceleration (PGA) is 1.5g. Among three types of members, the damage quantity of steel tube members is large but damage state is slight. The damage of concrete-filled steel tubular members (arch feet) comes early but damage state is slight. The damage state of reinforced concrete members (joint balance pier) is the most serious. Attention should be paid to the corresponding structural locations in seismic design.