Study Of Dynamic Character And Vibration Of Vehicle-Bridge Of Long-Span Concrete Filled Steel Tube Arch Bridges

In recent years,as a new-type bridge, concrete-filled steel tubular(CFST) arch bridge has been deeply developed in our country's construction, for its own merits and can luckily make agreement with the factual situation of bridge engineering. Accordingly, investigators and devisers should increasingly attach more importance to their dynamic behaviors.Vibration problem of the vehicle-bridge system is a question of random force vibration. In this thesis, the vibration equations of two planar degrees of freedom are built, and the vehicle-bridge coupled vibration equations are also built; the same as the random road surface, the random surface of a bridge can be described by the power spectral density function, and the dynamic response of vehicle-bridge system caused by the roughness can be computed.This paper represents the development of the theory of impact coefficient in bridge, taking the example of QianDaohu CFST arch bridge, establish 3-D finite element model of it with software ANSYS, and analyze its natural vibration. This discussion estimates the dynamic capability of QianDaohu CFST arch bridge when the loads of the vehicle pass, and the author analyze the effect on the dynamic capability, when the factors of the surface roughness of bridge deck, the velocity of the vehicle change, basing on them, and analyses the influencing factor of impact coefficient in QianDaohu CFST arch bridge, which include vehicle speed,vehicle quality,the surface roughness of bridge deck and so on. Thereby, it provides a certain testimony to the selection of impact coefficient about the CFST arch bridge.