Research On Vibration Comfort Of Footbridge Induced By Pedestrian Excitation

With high-strength materials, new structure, new construction technology and modern methods of structural analysis used, the pedestrian bridge strides greatly to light quality, long-span and soft. The self vibrate frequency of the structure is more and more low. The pedestrian bridge can be easily triggered a sharp vibration under pedestrian excitation. It is necessary to analysis the pedestrian bridge vibration and to evaluate the pedestrian comfort in the design stage. Therefore, taking Hangzhou-Shaoxing crossing overline Pedestrian bridge as an example, the pedestrian bridge vibration comfort under pedestrian excitation was studied systematically by use of the restricted dynamic response method.First, by reading literature and technical information home and abroad, the current national standards of evaluation Pedestrian bridge vibration comfort method are analyzed and compared among the British BSI5400, Euro code, Sweden Bro2004 and the International Organization for Standardization's ISO. The pedestrians excitation load mode and comfort evaluation index were developed.Secondly, by using three-dimensional dynamic finite element method and software ANSYS, the vibration characteristics of the junction of Hangzhou-Sliaoxing crossing overline Pedestrian bridge were analyzed to grasp the basic form of vibration. The finite element method model reliability was verified by pulsation experiment.Then, based on the proposed pedestrian load model, using ANSYS APDL languages, the flow procedures to predict the vibration response under pedestrian loads was developed. On the basis of the analysis of the Shaoxing road pedestrian bridge vibration excitation in various load mode, a comparative study on vibration response and comfort evaluation results were made under different norms.Finally, taking Shaoxing crossing overline pedestrian bridge across the main bridge and the bridge D of the largest span footpath as object, a field measurement research of structure vibration response under pedestrian load is performed. Comparing the measured results about the test that the crowd inspired the structure vibration with the theoretical values according to the different norms and the presumption, the reliability of the method used in the evaluation of the vibration comfort was verified.