The Research Of Coupling Vibration Of Vehicle-bridge In The High-pier & Long-span Continuous Rigid Frame Bridge

As continuous development of the national economy and significant increase of the traffic volume in Chinese passenger and freight transportation, vehicular load running on the highway bridge is increasing heavily; at the same time many new bridges are designed comparatively slender and soft, and the high-pier & long-span continuous rigid frame bridge is one type of them, therefore the problem about coupling vibration of vehicle-bridge becomes more prominent than before. It includes two aspects, one is the dynamic impact action which is produced by the high-speed running vehicle on the bridge that it passed, will directed affect the active state and operating life of the bridge; the other aspect is that the vibration of bridge will also affect the stationarity and security of running vehicle. Thus coupling vibration of vehicle-bridge must be comprehensively analyzed. On the basis of collection and arrangement of existing coupling vibration of vehicle-bridge's dynamic datum, this paper discusses the basic procedure of finite-element method about dynamics and the merits and demerits of all kinds of numeric analysis in them; meanwhile, it deduces the equations set of motion of coupling vibration of vehicle-bridge under the condition of autologous assumption. What's more, making use of visual-procedure language Vc++, writes a generator professional program for analyzing the coupling vibration of vehicle-bridge (CQZD). Taking the Bu-Liu River Bridge in GuangXi as a subject, firstly the paper calculates dynamic response value that the vehicle runs at the designed speed on the Bu-Liu river bridge by adopting the CQZD programmer. This response includes three parts, for example, vertical component of the dynamic response of box-beam,vehicle and horizontal component of the dynamic response of high-pier, moreover it summarizes dynamic response situation of the whole system when the vehicle run on the bridge. Secondly, it analyzes the parameters of Bu-Liu River Bridge's coupling vibration of vehicle-bridge, which include some influencing factors such as vehicle speed,vehicle quality,its type and damping ratio,bridge's damping ratio and so on. It also demonstrates the existence of sympathetic-vibration point and the running smooth of vehicles from the respect of vehicle speed. Comparatively speaking the coupling vibration of vehicle-bridge changes more sensitively under the influence of vehicle speed and quality. At last, this paper represents the development of the theory of impact coefficient in bridge, based on them, analyses the influencing factor of impact coefficient in Bu-Liu River Bridge, which include vehicle speed,vehicle quality,bridge basal frequency and vehicle line and so on. Thereby, it provides a certain scientific testimony to the analysis of coupling vibration of vehicle-bridge about the high-pier & long-span bridge.