Noise and vibration from railway inclined turnout

Abstract

Railway noise and vibration control at turnouts and the associated groundborne noise and viaduct re-radiated noise are major environmental concerns for railway projects in urban area. For new railway lines in Hong Kong, inclined turnouts are used in mainlines (instead of vertical turnout) for smooth load transfer at turnout, and reduction of noise and vibration from the turnout. According to the practice in the world (Calculation of Railway Noise by Dept of Transport in UK, Transit Noise and Vibration Impact Assessment by Federal Transit Administration in USA, etc.), noise and vibration levels from turnout would be higher than that from normal railway track in the range of 2.5dB to 10dB. According to the practice in Hong Kong, +7dB turnout correction is adopted for airborne noise calculation, and +5dB and +10dB turnout corrections are adopted for groundborne noise calculation for inclined and vertical turnouts respectively. This paper presents noise and vibration measurement results at various setback disances from turnouts and discusses the turnout corrections for various operation conditions.