Ambient vibration analysis of adjacent parallel multi-tunnels under train loads

At present, the commonly-used evaluation criteria for the ambient vibration caused by train vibrating loads are based on the test data and calculated results of one train, which can not reflect the real vibrating situations with multi-tunnels because of the rapid development of rail transit in China. There are four tunnels crossing each other between Hongshan Square Station and Zhongnan Road Station for the second line and the fourth line of Wuhan rail transit. The complicated multi-tunnels are simplified as four adjacent parallel tunnels with different distances according to their practical characters. Three-dimensional models are established, and the ambient vibration and spectral characteristics are analyzed with different train numbers, tunnel depths and tunnel net distances. An approximate empirical formula is suggested based on the calculated results, and the vibrating influence areas are determined accordingly. The results can provide references for the forecast and evaluation of the ambient vibration of similar projects in China in future.