Design and Implementation of Measures to Reduce the Vibration Levels of Metro Trains

Since November 2012 there has been a local increase of vibration levels at the metro system in Amsterdam. At this location, the vibration levels have increased by more than 10 dB with a strong component around 80 Hz. At other locations in the same area, no increase of vibration levels is found. A combination of pass-by measurements and ARRoW measurements, vibration measurements on a moving train, revealed the root cause of the high vibration levels. The track was heavily corrugated with excitation of the resonance of the unspring mass on the track stiffness due to an impact when driving over a joint in the track. Two measures were taken: (1) replacement of the joint and (2) grinding of the track. After these measures were taken, the pass-by vibration measurements were repeated. The results show a strong decrease of the measured vibration levels and have proven that the measures have been very effective.