Use of conventional site investigation parameters to calculate critical velocity of trains from Rayleigh waves

摘要

This paper presents a practice ready approach to calculating railway track critical velocity from Rayleigh waves and ground borne vibrations using conventional site investigation parameters. The different types of ground wave are discussed together with equations defining the wave velocities mathematically.Relationships between the terms in the equations defining Rayleigh Wave velocity and thus track critical velocity are established – enabling the reader to undertake these calculations from a standard low cost site investigation.It is suggested that the design “train critical velocity” may be restricted to 0.7 x Rayleigh Wave velocity. However it is reported that the “track critical velocity” is in the region of 1.1-1.3 x Rayleigh Wave velocity.