Measured shock pressures in the splitting of dimension stone

摘要

The shock pressure generated when an explosive detonates in a borehole in granite was measured using a piezoelectric gauge suspended in an adjacent water-filled hole. Explosive charges used were typical of those applied for splitting dimension stone - detonating cords of various charge weights and a small diameter, low velocity dynamite. A variety of shock absorbing and transmitting media was used in the charged boreholes, including air, water, sand, and a new special-purpose shock absorber for controlled blasting called B-Gel. The measured pressures were found to depend very significantly on the shock absorbing media, both in the intensity and shape of the pressure pulse. Pressures from water-filled shot holes were 5 to 10 times higher than when air or sand filled the space around the detonating cord. The B-Gel shock absorber lowered the leading peak of the shock signature compared to water.