3rd Conf on Explosives and Blasting Techniques Soc Exp Eng Pittsburgh, Pennsylvania, 1977 Feb; :34-47
Increased mineral consumption and environmental concern have caused much interest in potential damage and annoyance from ground vibration and airblast produced by production blasting in surface mines and quarries. Ground vibrations are blamed for shaking structures, but often the airblast is responsible, particularly when the distances from mine to structure are large. Simultaneous measurements of ground vibrations, structure vibrations, and indoor and outdoor noise from blasting are being used by the Bureau of Mines to determine the relative importance of the ground and airborne blast energy in shaking the structure and making windows, dishes, etc., rattle. Properly designed blasting produces an airblast wave that is predominately infrasonic (1.5 Hz). This is well below the frequency range of human hearing and typical structure response, and even below the frequency range of most noise- measuring instrumentation. In noise-sensitive neighborhoods, care should be taken to minimize the generation of high levels of airblast. Possibly more important, reducing the amount of high- frequency noise through the careful use of detonating cord and the possible reorientation of the operating face can help control adverse environmental effects on mine and quarry neighbors.
3rd Conf. on Explosives and Blasting Techniques, Soc. Exp. Eng., Pgh., Pennsylvania, Feb. 1977, PP. 34-47