Wind Resistance Research On Vehicle-bridge System Of Beam-arch Combination Railway Bridge In Coastal Areas

This paper is part of the research item "Wind tunnel experiments study on the aerodynamic characteristics of vehicle-bridge system for high-speed railway and overturning resistance of train under strong wind environment", which is financed by the National Natural Science Foundation of China (Grant No.51178471). The pre-stressed concrete continuous beam and concrete-filled steel tube arch association bridge(the length of which is (64+136+64) m), in Wen-Fu Railway, of Kunyang super bridge is investigated. By employing the well-known FEM software Fluent6.3, and applying the principles of fluid dynamics, the aerodynamic performance of the super bridge and the integrated system between high-speed train and bridge under the effect of cross-wind is investigated by numerical simulation of the flow field. In the mean time, by applying the static balance principle, the influence of the cross-wind on the train overturning stability is considered under the normal operating conditions. The Kunyang full-bridge model is constructed based on the Beam-Grid Method and by employing the finite element analysis software Midas/Civil. The effects of the wind loads on the arch of the beam, the tensioning force in suspenders, and the wind loads on the train on the stability of the full-bridge are also analyzed, which provides many technical parameters for the future wind tunnel tests and a good reference for similar engineering projects. Mainly the work of the following aspects is implemented:1. The application of the beam-arch combination bridge to the railway, and the basic theory and numerical method for computing the static coefficient of bridge and train cross-section are illustrated in details.2. Based on the flow field analysis program FLUENT, the aerodynamic coefficients of several major beam cross-sections and arch ribs under the combined effect of the sound barrier and arch rib are adopted, and the effect of the arch ribs on the aerodynamic performance of the major beams, and the effect of the major beams on the aerodynamic performance of the arch ribs are analyzed.3. Through considering the influence of the train on the wind resistance performance of the bridge and the aerodynamic performance of the train itself, an integrated model of vehicle-bridge system is constructed, and the aerodynamic coefficients of the major beams and the train of the Kunyang Bridge, when the train is located at the left hand lane, right hand lane, and the intersection, is calculated respectively. After calculation of the overturning moment of the high-speed train, the overturning stability of the train under the effect of cross-wind is studied.4. The integrated Midas Beam-Grid Model of the Kunyang Super Bridge is constructed, the stability of the bridge during the operational phase under the effect of the wind load is verified to meet the requirements of the occupational standard. In addition, the tensioning force in suspenders, and the influence of the wind loads on the train to the stability of combined deck-continuous beam and arch structure are discussed. The lateral buckling of the arch ribs under the cross-wind effect is also presented.