Environmental vibration induced by elevated railway traffic using thin-layer method

The thin-layer method(TLM) is a semi-analytical and semi-numerical approach for the analysis of elastic wave propagation in stratified media.The frame reactions,which were calculated by the computer program of the train-bridge system's dynamic analysis,served as the exciting loads on the elevated railway frame.The frequency response functions of soils surrounding the elevated railway frame supported on group piles foundation with footing,on the typical Shanghai soil site,were calculated by TLM.Based on the exciting loads and the frequency response functions,the acceleration response and vibration level of surrounding site can be obtained.Single frame model and multi-frame model were adopted to calculate the environmental vibration induced by the elevated railway traffic.The comparison between the calculated vibration level with that of the measured regressive formula shows that the model and method proposed in this paper is feasible for the evaluation of the environmental vibration induced by the Shanghai elevated railway traffic,and that the effect of the adjacent frames is very small.The analytical model proposed in the paper is feasible for the analysis and evaluation of the environmental vibration induced by elevated railway traffic.