Long-Term Efficient Control of Structure-Borne Noise Inside Buildings Caused by Underground Railways by Using Novel Damping Fasteners

Damping fasteners provide vibration isolation to railway tracks because of their low vertical stiffness and improve the in-service performance of the tracks. In this paper, a new type of high lateral stiffness and vertical damping fastener is developed. First, the vibration suppression frequency band of the new fastener was determined from a field test, the design vertical stiffness was determined by calculating the P2 resonance frequency, and the vertical stiffness before and after a fatigue load test was found. Then, field experiments were carried out in buildings with known excessive subway train-induced vibration problems to assess the effectiveness of the proposed fastener, which showed that the damping fasteners reduced the vertical and transverse vibrations of the tunnel wall by 10 dB without increasing the transverse displacements of the rail. Furthermore, the structure-borne noise reduction in all measured buildings exceeded 3 dB. The study demonstrated that the replacement of novel damping fasteners is a feasible solution for controlling vibrations and noise in buildings adjacent to subway lines.