The Acoustic Response of Structures to Blast-Induced Ground Vibration:Fact or Fiction

摘要

It is widely recognised that complaints from members of the public relating to blasting operations are related to both ground vibration and air overpressure. It is also known that a complaint is more likely to be generated if the person is inside of a structure at the time of the blast. Reports relating to such complaints often refer to 'noise' inside the structure with terms like 'rattling' commonly being employed. Such acoustic response is widely perceived within the blasting industry to be directly related to high levels of air overpressure although there appears to have been very little research carried out specifically related to this effect.This paper describes the initial findings from a research project specifically designed to investigate this phenomenon, carried out by the Blasting and Environmental Research Group, The University of Leeds, England. The Minerals Industry Research Organisation (MIRO) under the terms of the UK Government's Mineral Industry Sustainability Technology (MIST) program has funded this project.The paper outlines the development of a monitoring system designed to record levels of acoustic noise inside structures whilst simultaneously monitoring levels of vibration and air overpressure. The system has been designed to enable high quality sound recordings to be made giving the possibility of identifying the structural component generating the noise. Initial findings from the project have confirmed that the level of structural noise is directly related to ground vibration. In the structures studied to date, there is little or no demonstrable connection between levels of air overpressure and acoustic response.