Acceleration Response Spectrum Method Of Structure Under Pedestrian Excitation And The Analysis Of Crowd Excitation

Structure vibration due to human activities is an important problem in serviceability design of the light and flexible structures. Some structure had to stop using just after finishing because of excessive vibration. It is necessary to study the problem of structure vibration. This problem was studied from the point of view of structural engineering and ergonomics in this article.It is summarized of the study actuality of the problem and the analysis method of the study. Through the method proposed by Ellingwood, the loads acting on footbridge were formed using typical footfall traces. Then, after a large amount of dynamic simulations on structure of different shapes, spans and damping, the maximum acceleration response spectrum and the RMS acceleration response spectrum was achieved. Ater the analysis and sumarizaion of result, a shortened form method that can caculate the maximum acceleration and the RMS acceleration of structure was brought forward. This method found in the statistic and analysis of the caculate result, and can be used in the evaluation of the structure's serviceability.There is little research deal with the vibration problem of structure induced by crowd, but actually, structure is effect by crowd. Monte-calo method is adopted to research the dynamic response of structure under the excitation of crowd. Through nearly 20000 times' simulating of each condition, a lot of dynamic response sample can be achieved. After the analysis of result, the conclusion that response sample are subject to normal distributing. Comparing the analysis result of different number of people, it is found that the dynamic response growing as the number of people increase. Farther, through regressive analysis, the function relation of the response growing and the crowd can be achieved.