Ground vibration boom
Ground vibration boom is a phenomenon of very large increase in ground vibrations generated by high-speed railway trains travelling at speeds higher than the velocity of Rayleigh surface waves in the supporting ground.[1]
Technical background
This phenomenon, which is similar to a sonic boom from supersonic aircraft, was theoretically predicted in 1994. Its first experimental observation took place in 1997-1998 on the newly built high-speed railway line in Sweden (from Gothenburg to Malmo) for high-speed trains X 2000. At some locations along this line characterised by very soft ground (near Ledsgard) the Rayleigh wave velocity was as low as 45 metres per second (150 ft/s), and train speeds of only 165–170 kilometres per hour (103–106 mph) were sufficient to observe the effect. In particular, the increase in train speeds from 140 to 180 kilometres per hour (87 to 112 mph) was accompanied by about tenfold increase in generated ground vibration level, which agrees with the theory. It is now understood that, with the increase of operating train speeds, this phenomenon represents a major environmental problem associated with building new high-speed railway lines.[2][3][4]
Mitigation measures
The most efficient way to mitigate ground vibration boom is to reduce train speeds at locations where Rayleigh wave velocities in the ground are very low.[5] If this is not desirable, e.g. for economic reasons, some mitigation measures can be applied, such as stiffening of railway embankments or building protective trenches and barriers between railways and residential or industrial buildings. Any mitigation measures would involve the specific ground investigation works along the route.[6]
References
- "Ground vibration boom". Railway Gazette. 1 June 1998.
- "The Application and Effect of the Rayleigh Wave Speed Principle on High Speed Rail travel - Written evidence from David Rayney". UK Parliament. 15 May 2011.
- "Derailment fears over high speed rail scheme". Express & Star. 20 February 2012.
- "From the Archives: Rayleigh Waves and HS2". STOP HS2. 8 July 2014.
- "Railing against Rayleigh Waves". STOP HS2. 14 March 2016.
- "HS2 defends itself against derailment claims". Rail Technology Magazine. 14 March 2016.
Further reading
- Gilligan, Andrew (19 February 2012). "High Speed Rail Link 'at Risk of Derailment' because of 225mph Trains". The Telegraph.
- Grundmann, H.; Schueller, G.I., eds. (2002). Structural Dynamics: EURODYN 2002. Vol. 2. A.A. Balkema, Lisse. ISBN 90-5809-512-6 – via Google Books.
- Krylov, V.V. (1994). "On the Theory of Railway-induced Ground Vibrations". Journal de Physique IV. Vol. 4, no. C5. pp. 769–772 – via CCSD HAL.
- Krylov, Victor V., ed. (2001). Noise and Vibration from High Speed Trains. London: Thomas Telford Publishing. ISBN 0-7277-2963-2 – via Google Books.
- Skipp, Bryan O., ed. (1998). Ground Dynamics and Man-made Processes. London: The Institution of Civil Engineers. ISBN 0-7277-2676-5 – via Google Books.
- Takemiya, H., ed. (2005). Environmental Vibrations: Prediction, Monitoring, Mitigation and Evaluation. London: Taylor & Francis Group. ISBN 0-415-39035-4 – via Google Books.