Laserfiche WebLink
Review of Blasting Operations at Robinson Brick Company's Siloam Clay Mine <br /> even cosmetic damage (0.5 in/sec in homes with plaster walls). The intensity of vibration is <br /> reduced when scaled distance is increased. <br /> For blasting at the Siloam Clay Mine, the maximum charge per delay could be limited to 50 <br /> pounds per delay. At this limit, the scaled distance to the nearest occupied dwelling (the Bush <br /> residence), located approximately 2,850 feet from the blasting area, is 396 ft/lbt'z. <br /> SD= 2' 00 = 396 ft / lb"' <br /> At this scaled distance, using conservative response constants in the vibration prediction formula <br /> shown in equation 2.1, the ground motion at the nearest structure would be around 0.02 in/sec. <br /> PPV = 300 396 -1.6 = 0.02 in / Sec <br /> The intensity of this motion is 250 times lower than the 0.5-in/sec-damage-threshold limit. The <br /> intensity of ground motion at the Lammert Barn—at 2,500-ft, and a scaled distance of 354 ft/lb112, <br /> would be likely not exceed 0.03 in/sec. Since this is the closest structure, it is clear that blast- <br /> induced ground motion at nearby structures will be orders of magnitude lower than the threshold <br /> of damage. Based on this finding, if charge weight per delay is limited to 50 pounds per delay, <br /> GEOTEK concludes that blast-induced ground vibration will cause no damage to adjacent <br /> property. <br /> GEOTEK& Associates, Inc. Page 9 January 99 <br />