Vehicle-Bridge Coupling Vibration Of Continuous Box Girder Bridge With Corrugated Steel Webs

The corrugated steel webs box girder bridge as a new type bridge has the advantages of light weight, good seismic performance, convenient construction and installation and so on. Domestic and international research on it is gradually to the direction of large span continuous beam, but its vehicle-bridge coupling vibration problem is not specialized deep enough. Therefore, studying the vehicle-bridge coupling dynamic characteristics of large span continuous beam bridge of corrugated steel webs has important theoretical significance and practical value.In this paper, vehicle is in three-dimensional model. Using modal synthesis method, vehicle and bridge could be seen as a interaction system, our country highway commonly used car model parameters were collected and arranged, the natural frequency of vehicle was calculated and parameter was validated. Based on the actual corrugated steel webs box girder bridge, Midas/Civil was utilized to establish the modal of3span continuous bridge with corrugated steel webs,3span frame bridge with corrugated steel webs,5span continuous bridge with corrugated steel webs and model is validated. The vehicle-bridge coupling vibration effect of vehicles in different speeds, different loads, different types,different road irregularity amplitudes and wave lengths were calculated and analyzed. The results showed that:The surface irregularity amplitude mainly affects the vibration amplitude, when irregularity wave length and speed coupling excitation frequency are close to the natural frequency of bridge, the phenomenon of resonance will happen. Vehicle weight is the major factor affecting the midpoint deflection, and the relationship between load and bridge deformation is basically linear. The heavier the vetical load is, and the larger the midpoint deflection. When vehicle travelling at a certain speed, vehicle-bridge coupling vibration is influenced by the combination of vehicle natural frequency, vehicle excitation frequency and road irreglarity. For large span continuous box girder bridge with corrugated steel webs, pavement irregularity is the main factor influencing the vibration of the bridge.In order to improve the torsional perforrmance of continuous box girder bridge with corrugated steel webs,3type diaphragm arrangements were set up, and the vehicle-bridge coupling vibration was calculated and analyzed under that. The results show that:the diaphragm in midspan makes good performance in reducing midspan deflection, and diaphragm near pier can reduce the vibration amplitude and acceleration of midspan.