Field measurements of aerodynamic pressures in high-speed railway tunnels

Abstract

When a train travels through a tunnel at high speed, obvious pressure transients are generated because of the restricted airspace within the tunnel, which have an impact on the comfort of passengers and the structural safety of the train and the tunnel. In this paper, by performing a series of field measurements for high-speed railway tunnels in China, the aerodynamic pressures at different test points in the tunnels were obtained; the formation mechanism of pressure, the distribution of amplitude and the attenuation of pressure were analyzed. The results show that after the train travelled out of the tunnel, the pressure continued to fluctuate according to a fixed cycle and the pressure amplitude decreased exponentially as the number of cycles increased. The attenuation coefficient of the pressure had nothing to do with the train speed, but was associated with the tunnel length, the position of test points and the holes of the tunnel hoods.