Distortion of compression wave propagating through Shinkansen tunnel

Abstract

When a compression wave generated by a train entering a tunnel is propagated through the tunnel and reaches the exit portal, a pressure pulse ('micro-pressure wave') is radiated from the exit portal. The distortion of the compression wave during propagation in the tunnel is important for estimating the magnitude of the micro-pressure wave radiated from the exit portal. In this paper, the dependence of the distortion of the compression wave on the initial waveform at the tunnel entrance is investigated. First, a simple system of equations concerning the wave propagation in the tunnel is described. Secondly, theoretical and numerical investigations into the effects of nonlinearity and unsteady friction on the tunnel wall on the distortion of the compression wave are made. © 2008 Springer-Verlag Berlin Heidelberg.