Dynamic analysis of a large span specially shaped hybrid girder bridge with concrete-filled steel tube arches

In the present study, the dynamic property of a specially shaped hybrid girder bridge with concrete-filled steel tube (CSFT) arches is investigated based on experimental and numerical methods, especially under moving vehicles. Before the inauguration of this bridge, a dynamic field test was conducted. A refined three-dimensional finite element model is built to represent the complex structural mechanic property of the bridge. The vehicle-bridge coupled vibration (VBCV) model with a 16 DOF vehicle model is established to simulate the dynamic behavior of the bridge with moving vehicles. The FE model is updated, and the VBCV model for the bridge is verified, taking advantage of the aforementioned measured data. The result indicates that the proposed VBCV numerical model can closely reproduce the measured response and can be used to simulate the dynamic behavior of the bridge under various conditions. The impact effect, ride and pedestrian comfort, and related parameters analysis for the bridge with moving vehicles are studied by numerical simulations and experimental tests. The results indicate that the impact factor formula from design standards significantly underestimates the dynamic impact effect, which may result in an unfavorable influence on the bridge safety. Several conclusions are drawn for this bridge, and further research that is needed for this new bridge type is discussed.