ASSESSMENT OF LOCATIONS ALONG THE PROPOSED HS2 ROUTES THAT ARE LIKELY TO EXPERIENCE GROUND VIBRATION BOOM FROM HIGH-SPEED TRAINS

摘要

The demand for high speed rail transportation has significantly increased over the last decade. This way of transportation is convenient and environmentally friendly. However, high train speeds bring into consideration some new environmental problems that were unknown for conventional trains. One of the most important is a dramatic increase in the level of railway-generated ground vibrations that can occur when the train speed exceeds the velocity of Rayleigh surface waves in the supporting ground. This phenomenon is known as 'ground vibration boom' (GVB), and it was first predicted theoretically in the papers. Soon after that, it was observed experimentally on the new high-speed railway line in Sweden. Further theoretical investigations of GVB have been carried out in the papers. Note that the phenomenon of ground vibration boom from high-speed trains is similar to the well-known phenomenon of 'sonic boom' from supersonic aircraft that occurs when the speed of aircraft exceeds the velocity of sound in air. The essential difference though is in the fact that, whereas sound velocity in air is roughly the same in all locations above earth surface, the Rayleigh wave velocity is different in different locations, depending on geological properties of the ground. In some locations, where the ground is soft and marshy, the Rayleigh wave velocity can be very low. Such 'sensitive' locations are most likely to experience ground vibration boom from operating high-speed trains.