Experimental evaluation and numerical interpretation of various noise mitigation strategies for in-service elevated suburban rail

This research evaluates the efficiency of five noise mitigation measures including rubber floating slab track, straight noise barrier, track acoustic absorber, track-side noise barrier, semi-closed noise barrier, and a combined strategy on an elevated railway through in-situ measurements. In-situ experiments were conducted by sequentially installing various mitigation measures for comparative evaluation. A numerical model was then developed to interpret the noise control characteristics of the mitigation measures. The experimental results indicate that the rubber floating slab track can mitigate bridge-borne noise by0-4 dB sound pressure level (SPL); the track acoustic absorber can mitigate the railway noise by 3-5 dB(A) and its combination with track-side noise barrier boosts the insertion losses of SPL by 2-7 dB(A). The combined control strategy shows overall better performance than individual mitigation measures within the efficient noise reduction regions. The experimental and numerical results can serve as a guide on the design of noise control strategies for elevated railways.