Mine roof vibrations from underground blasts.
Olson-JJ; Dick-RA; Condon-JL; Hendrickson-AD; Fogelson-DE
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 7330, 1970 Jan; :1-55
Previous Bureau of Mines studies of vibrations from quarry blasts have shown that the square root of the charge weight may be used to group particle velocity data from various charge sizes, and that empirical propagation equations may be used to estimate vibration amplitudes. Particle accelerations of the sandstone roof of the White Pine Copper Mine, Michigan, were measured to determine whether similar propagation equations may be developed for underground mine blasts. Vibration data from White Pine blasts were best grouped by scaling with the square root of the charge weight. Cube root scaling did not effectively group the data. The empirical propagation equation aw1/2 = 50,000 (r/w1/2)-2.21, Where a is peak- to-peak acceleration in g's, w is the zero-delay charge weight in pounds, and r is the distance from the blast in feet, may be used to estimate maximum vibration amplitudes from production sized blasts. Vibration differences among headings and types of explosive charge (AN-FO and dynamite), while statistically significant, were n t a major factor in the estimation of maximum vibration amplitudes with an empirical propagation equation. Vibration differences between types of explosive charge were larger than the differences among headings, indicating that some reduction of vibration amplitude might be gained by using AN-FO rather than dynamite.
Mining-industry; Underground-mining; Vibration; Explosions; Blasting-agents
IH; Report of Investigations
NTIS Accession No.
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 7330