Stability load-bearing capacity of large-span half-through CFST arch bridge

The whole failure process of the large span half-through Concrete-filled steel tubular (CFST) arch bridge under design load case is analyzed with the consideration of both geometric and material non-linearity. The purpose of the analysis is to obtain the influence of different analysis model, the whole bridge model and simplified arch model, on stability load-bearing capacity of large span CFST arch bridge. In the former model, the loads are applied on the deck; in the later model, the loads are applied on the arch ribs as concentrated forces along the hangers. It is shown that the large span half-through CFST arch bridge generally suffers ultimate point stability failure under design load case. Non-conservative forces contribute greatly to both the in-plane and out-of-plane stiffness of the bridge, which will increase the load-bearing capacity of the structure dramatically. As far as the calculation case is concerned in this paper, there is a great difference between the two load-bearing capacity of elastic stage and elastic-plastic stage, representatively.