Accession Number : AD0283296

Title :   SOME ASPECTS OF COUPLING BETWEEN EXPLOSIVES AND ROCKS

Corporate Author : NAVAL ORDNANCE TEST STATION CHINA LAKE CALIF

Personal Author(s) : HAAS,CHARLES J. ; RINEHART,JOHN S.

Report Date : JUL 1962

Pagination or Media Count : 1

Abstract : The work done in the field of explosive coupling is summarized. Generally, three zones of material behavior are considered when an explosive is detonated in contact with a material. These are the hydrodynamic zone, transition zone, and elastic zone. In seismic studies the term coupling refers to the production of strong seismic signals while decoupling refers to methods of decreasing the amplitudes of seismic signals suchAS DETONAOUPLING FACTOR FOR SUCH EXPERIMENTS IS DEFINED AS THE RATIO OF THE SEISMIC SIGNAL AMPLITUDE FOR A FULLY TAMPED SHOT TO THE SIGNAL AMPLITUDE OF A SHOT OF THE SAME SIZE IN THE GIVEN CAVITY. A similar ratio has been defined for peak particle velocities. When explosive performance is related to rock breakage both dynamic shock effects and expansion effects of the explosion gases must be considered. United States ing the explosive in an underground cavity larger than the explosive charge. The decoupling factor for such experiments is defined as the ratio of the seismic signal amplitude for a fully tamped shot to the signal amplitude of a shot of the same size in the given cavity. A similar ratio has been defined for peak particle velocities. When explosive performance is related to rock breakage both dynamic shock effects and expansion effects of the explosion gases must be considered. United States Bureau of Mines investigators have defined two decoupling factors: the ratio of charge diameter to hole diameter and vice versa. They have related the amplitude and period of the strain pulse in rock to these decoupling factors. (Author)

Descriptors :   *SEISMIC WAVES, *UNDERGROUND EXPLOSIONS, ACOUSTIC IMPEDANCE, BLAST, NUCLEAR EXPLOSIONS

Distribution Statement : APPROVED FOR PUBLIC RELEASE