Seismic Response Analysis of Multi-Span Continuous Deck-Type Reinforced Concrete Double Ribs Arch Bridge

Reinforced concrete rib arch bridge is widely used in southwest of china, therefore, it is practically significant to assess the seismic performance of this kind of bridge. In this paper, a deck-type double ribs arch bridge which has eleven large continuous spans is taken for instance. The finite element calculation models for the bridge are established considering arch effect. The M-method principle is used to simulate the pile-soil-structure interaction (PSSI), and multiple Ritz vector method is introduced to analyze the dynamic characteristics. Moreover, the seismic response of arch bridge is analyzed by the response spectrum method. Numeral results show that, the dominant vibration mode of the Multi-span continuous deck-type reinforced concrete rib arch bridge is out-of-plane mode, owing to the weak lateral stiffness. The arch effect can reinforce the longitudinal stiffness of bridge, but weaken the lateral stiffness. Combined with horizontal direction orthogonal seismic action, arch effect can significantly reduce the axial force of rib, while increase the moment and shear of the arch foot and the displacement of the arch. The rib arch, the 1/4 points and the junctions of ribs and beams are the seismic control points. PSSI is the key factor of bridge seismic.