Comparison of Barriers and Partial Enclosures for Rifle Range Noise Reduction

摘要

The noise from small-arms firing at Army rifle ranges can disturb the surroundingcommunity, generating complaints and attempts to curtail necessary training activities. The U.S. Army Construction Engineering Research Laboratories (USACERL) is developing methods to reduce such noise disturbances. This investigation experimentally and analytically compared the rifle range noise reduction of barriers and partial enclosures. The barrier was a wall located behind the firing line, and the partial enclosure was an open front shed with the firing line located within the shed. Results of the experiments showed that the shed did not outperform the rear wall, a significant outcome because walls are less expensive to build than sheds. Evidence substantiates that this is primarily a consequence of gun muzzle blast directivity. Barrier design curves were also generated by experimental algorithm. The optimum distance from rifle to rear wall for maximum insertion loss was calculated to be about 5 m for the test configuration. An investigation into the effect of sound wave interaction with the ground on achieved noise reduction at the test site showed that excess attenuation for a propagation path close to the ground can substantially reduce achieved barrier insertion loss. Firing shed, Rifle ranges, Noise barriers, Noise reduction.