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EXPECTED GROUND VIBRATION LEVELS <br />Research has shown that ground vibrations generated from quarry blasting can be accurately predicted <br />by the use of a fundamental equation defining the rate at which energy dissipates with respect to <br />distance. To predict produced ground vibrations, two factors are of key importance: The amount of <br />energy generated (pounds of explosives per 8 rns delay) and the distance from the energy source. <br />Particle velocity is utilized to quantify the magnitude of ground vibrations. Peak particle velocity <br />(PPV) is defined as how fast a particle is moved by passing seismic waves and is measured in inches <br />per second. A predicted PPV can be derived from the following general use equation: <br />p-' PPV = 160~(Ds) "t'6 where Ds =scaled distance <br />f <br />The scaled distance (Ds) is a fundamental relationship between distance in feet from the blast and the <br />ma~dmum explosive charge weight in pounds per 8ms delay period. It is expressed as the distance, in <br />feet, divided by the square root of the charge weight per delay in pounds: <br />Ds = D/W °'3 where D =distance in feet from the blast <br />W =charge weight per delay in pounds <br />The PPV equation is a very conservative general use velocity attenuation formula and is not site <br />specific. It was derived from data obtained over a wide range of geographically and geologically <br />different blasting sites and was published in the DuPont Blaster's Handbook (16th Edition, p. 426). A <br />more site specific formula can be calculated from future production blasts at the proposed quarry near <br />Parkdale, Freemont County, Colorado. <br />t~ <br />~. <br />r=_. <br />T <br />L <br />d <br />Agile Stone Systems, Inc. has indicated the utilization of approximately 480 pounds of explosives per <br />delay in future production blasts at the quarry. This assumes that the Pazkdale quarry will have a 50 <br />foot face, 6.75 inch diameter holes and 12 foot of stemming in future production shots. The following <br />table utilizes the DuPont equation for predicted PPV at the four closest structures to the proposed <br />quarry outside of Parkdale, Freemont County, Colorado: <br />LOCATION DISTANCE FRM <br />BLAST EXPLOSIVES PER <br />DELAY BS PREDICTED PPV <br />P.S. <br />STATE PARK 2,750 480 0.070 <br />WOOTEN RES. 3,100 480 0.058 <br />CLARK RES. 4,350 480 0.034 <br />CLEM RES. 5,350 480 0.024 <br />~: <br />