Rail Damper Composed of Tuned Mass Damper and Constrained Layer Adopted in Non-symmetric Rail

摘要

A tramway is installed on resilient booted sleepers for controlling groundborne noise at an open cut section connecting to tunnel. However, airborne noise impact was a concern for the surrounding houses. In order to reduce the air-borne noise emission from the non-symmetric profile groove rail (CEN 53R1), a new type of rail damper, which was consisted of tuned mass dampers and constrained layer, was developed for tackling the dominant noise frequencies from 250 Hz to 1200 Hz. Track decay rate, rail vibration levels, near-field noise and far-field noise levels have been studied for various arrangements of partial installation of rail dampers (four arrangements: baseline without damper, quarter pattern installation, half pattern installation and full installation) and were analyzed in the range of 500 Hz to 2000 Hz in 1/3-octave bands. During passby of two major types of trams in the operational fleet (namely the "old" and "new" trams), near-field noise reduction of 3.7 dB(A) and 4.2 dB(A) and far-field noise reduction of up to 4.3 dB(A) and 3.4 dB(A) were achieved respectively.