Vibrational impact of high-speed trains .1. Effect of track dynamics

The dramatic increase in speeds of modern passenger trains makes it important to consider the vibrational impact of such trains on the built environment. In the author's earlier paper in which a quasistatic approach to the calculation of track deflection curves had been used [V. V. Krylov, Appl. Acoust. 44, 149-164 (1995)], it had been shown that a very large increase in generated ground vibration level (about 70 dB, as compared to conventional trains) may occur if train speed exceeds the velocity of Rayleigh surface waves in the ground. Such a situation might arise, for example, with French TGV trains for which speeds over 515 km/h have been achieved. The present paper investigates the effect of track bending waves propagating in the system track/ground on railway-generated ground vibrations. It is shown that for train speeds approaching the minimal phase velocity of bending waves the level of generated ground vibrations is reduced. Theoretical results are illustrated by numerically calculated frequency spectra of ground vibrations generated by single axle loads traveling at different speeds and by TGV or Eurostar high-speed trains. (C) 1996 Acoustical Society of America.