Background
Expanded safety and vibration analysis for rock tunnels as a basis for a calculation model for calculating vibration dispersion from railway tunnels.
Assignment
On behalf of Implenia Sweden AB, Efterklang has established verifying vibration measurements in the Åsa Tunnel in Kungsbacka Municipality as a basis for a calculation model for calculating vibration dispersion from railway tunnels. The railway tunnel is part of the West Coastline that runs between Gothenburg and Lund. By carrying out measurements, steps can be optimized to protect residents and businesses in the surrounding area for future railroad tunnels.
The Åsa Tunnel has a track foundation with ballast and sub-ballast. A number of different types of trains operate on the West Coast Line including, among other things, freight trains, regional trains, Öresundståg [Öresund’s Trains] and X2000. Efterklang’s assignment ran continuously for a month, with almost 3,000 train passengers registered. Vibration levels in the tunnel wall were recorded as narrowband levels up to 1kHz. A huge amount of data has been collected for possible future analysis.
Result
Together with previously measured transmission functions, measured source strength in the Åsa Tunnel was used as input for the validation of a calculation model. The calculation model is used to calculate core noise levels from future rail traffic in the Varberg tunnel to surrounding dwellings.
The undertaking was carried out from November 2019 to January 2020.
Image: Illustrative
