Applications of noise barriers with a slanted flat-tip jagged cantilever for noise attenuation on a construction site

Abstract

Construction noise is one of the main sources of noise pollution in many cities, and degrades the comfort level of living spaces. It was previously reported that a noise barrier with a wide “cross-sectional profile” (e.g., T- or Y-shaped) could enhance the noise attenuation performance, and the jagged edge “longitudinal profile” on the top edge of the noise barrier could generate destructive interference sound fields behind the noise barrier, which could further reduce the noise levels. The present paper attempts to study the noise attenuation performances of jagged edge profiles applied on the edge of a cantilever, which was mounted at the top of a commercial passive noise barrier. In addition to the numerical simulations, the full-sized prototypes were also experimentally tested on a construction site with noise generated by a boring machine. Both numerical simulation and experimental results showed that this barrier with slanted flat-tip jagged cantilever would perform better than the traditional barrier having a Straight edge cantilever of same height, with a maximum additional attenuation of 5.0 dBA obtained experimentally. The barrier with a slanted flat-tip jagged cantilever could also extend the shadow zone behind the barrier to higher levels.