变截面钢桁梁人行桥行走荷载模型及试验研究OA

Since long-span pedestrian bridges are susceptible to yield excessive human-induced vibration response un-der walking loads,establishing a suitable load model is a necessity to evaluating the vibration response of pedestrian bridges.With a variable cross-section steel truss girder pedestrian bridge as the engineering background,a finite element model was established by Midas Civil code.Considering the loading effects of different pedestrian numbers and walking excitation fre-quencies,on-site tests of the pedestrian bridge were carried out.Based on the existing load calculation model and the testing data,a cosine series load calculation model considering the dynamic factors of 5 orders was established,and vibration simu-lation and analysis were carried out based on the model.The results show that the vibration response increases significantly when the pedestrian step frequency approaches First-order vibration frequency of the bridge.There is a large relative error between the analytical results obtained from the simulation of pedestrian loading by the load model considering the low-or-der dynamic load factors and the measured results.In contrast,the results obtained from the simulation of the cosine series model considering the fifth-order dynamic load factor are closer to the measured results.The research results may provide some reference for the accurate simulation of walking loads.