Measured and calculated noise reduction of rail dampers and absorption plates on a high speed slab track

Rail dampers and sound absorbing plates have been tested on a high speed railway slab track in a walled cutting at a noise sensitive location. Their noise reduction has been determined from pass-by measurements during service and predicted using BEM calculations. The cutting depth, noise barrier height and configuration vary along the length of the cutting. In service noise and vibration measurements were performed at several cross-sections along the track before and after installation of the measures, which were applied on test sections of 100 m length. Additional measurements have been performed at a track section without measures to determine the variability per train. For speeds of around 230 km/h, 2 dB(A) reduction was measured for rail dampers and 4 dB(A) for absorption plates. The effect of the investigated measures will vary with track cutting depth, track type, train type, train speed and height and configuration of any noise barriers. Comparison of the measured effects to the effects predicted by BEM calculations shows qualitative agreement. Therefore the BEM calculations have potential for assessment of other track sections and noise control measures.