The URL can be used to link to this page

Home My WebLink AboutPredictions Sunrock Prospect Hill S MartinoSeptember 4, 2019 Mr. Scott Martino CAROLINA SUNROCK 200 Horizon Drive, Suite 100 Raleigh, North Carolina 27615 RE: Predicted Ground Vibration and Air Overpressure Proposed Prospect Hill, NC Location Dear Mr. Martino: VibraTech VibraTechinc.com 377 Rubin Center Drive Suite 114 Fort Mill, SC 29708 Phone 803.548.3066 Fax 803.548.3083 Per your request, Vibra-Tech, Inc. offers the following vibration and air overpressure predictions based on loading information provided by Carolina Sunrock and Orica USA. Methods: The International Society of Explosives Engineers Blaster's Handbook, 18th Edition provides Equations 1 & 2 below that predict the peak particle velocity of a blast given the distance from the blast in question and the amount of explosives detonated per 8ms delay. Equation 2 represents a general industry prediction. According to Carolina Sunrock, blasting practices and geology will be similar to projected operations at the Prospect Hill site. Historical data, recorded at the Carolina Sunrock Kittrell Quarry, was used to determine Equation 3 for vibration prediction at the Prospect Hill site. Scaled Distance = Distance max. lbs. per delay [1] Peak Particle Velocity = 160 x (Scaled Distance)-1.6 [2] Peak Particle Velocity = 112 x (Scaled Distance)-1.71 [3] VibraTech The ISEE Blaster's handbook, 181" Edition also provides Equations 4 - 7 below as methods to predict peak air overpressure of a blast given the distance to the blast in question and the amount of explosives detonated per 8ms delay. Equation 5 represents air overpressure from a typical construction blast, whereas Equation 6 represents air overpressure from a typical quarry face: Cubed Root Scaled Distance = 3 max l distance [4] delay Peak Air Overpressure (psi) = 1 * (CRSD)-1.1 [5] Peak Air Overpressure (psi) = 1.32 * (CRSD)-0.97 [6] Con vertpsi to dB(L) = 20 * log psi [7] 0.0000000029 Given Parameters: Hole Diameter — 5.5 in Hole Depth — 50 ft Maximum Explosive Product Density — 73.04 Ibs/ft3 Given the variability in explosive product density, the maximum yield is considered when calculating the Peak Particle Velocity and Peak Air Overpressure. The following are the predicted values for Prospect Hill, using these equations and information provided by Carolina Sunrock and Orica USA. These predictions consider the closest point of pit development to the structure(s) in the surrounding area: /// VibraTech Peak Particle Velocity (Pit A): Address Distance from Blast (ft) Calculated Peak Particle Velocity Equation 2 (in/sec) Calculated Peak Particle Velocity Equation 3 (in/sec) 28 HENRY DANIELS RD 1128 0.305 0.139 206 BEAVER FALLS DR 1350 0.229 0.102 971 GOOSE CREEK RD 1526 0.188 0.083 115 BEAVER FALLS DR 1675 0.162 0.071 200 HENRY DANIELS RD 1784 0.147 0.064 950 GOOSE CREEK RD 1890 0.134 0.058 1238 WRENN RD 4053 0.039 0.016 2856 RIDGEVILLE RD 4058 0.039 0.016 2611 RIDGEVILLE RD 4263 0.036 0.014 2372 RIDGEVILLE RD 4275 0.036 0.014 2760 RIDGEVILLE RD 4292 0.036 0.014 3247 RIDGEVILLE RD 4305 0.036 0.014 2685 RIDGEVILLE RD 4379 0.035 0.014 2461 RIDGEVILLE RD 4400 0.035 0.014 2541 RIDGEVILLE RD 4400 0.035 0.014 3015 RIDGEVILLE RD 4417 0.034 0.013 2711 RIDGEVILLE RD 4442 0.034 0.013 2859 RIDGEVILLE RD 4560 0.033 0.013 2278 RIDGEVILLE RD 4572 0.033 0.013 2377 RIDGEVILLE RD 4650 0.032 0.012 2188 RIDGEVILLE RD 4917 0.029 0.011 2233 RIDGEVILLE RD 5000 0.028 0.011 2132 RIDGEVILLE RD 5140 0.027 0.010 4231 JOHN OAKLEY RD 5458 0.025 0.009 2592 WRENN RD 5478 0.024 0.009 2721 RIDGEVILLE RD 5701 0.023 0.009 1893 RIDGEVILLE RD 6385 0.019 0.007 /// VibraTech Peak Particle Velocity (Pit B): Address Distance from Blast (ft) Calculated Peak Particle Velocity Equation 2 (in/sec) Calculated Peak Particle Velocity Equation 3 (in/sec) 971 GOOSE CREEK RD 790 0.817 0.256 950 GOOSE CREEK RD 1430 0.316 0.093 2592 WRENN RD 2346 0.143 0.040 28 HENRY DANIELS RD 3150 0.089 0.024 200 HENRY DANIELS RD 3181 0.088 0.024 206 BEAVER FALLS DR 4077 0.059 0.015 115 BEAVER FALLS DR 4373 0.053 0.014 1238 WRENN RD 5095 0.041 0.011 2372 RIDGEVILLE RD 5203 0.040 0.010 2278 RIDGEVILLE RD 5290 0.039 0.010 2188 RIDGEVILLE RD 5376 0.038 0.010 2132 RIDGEVILLE RD 5500 0.037 0.009 2611 RIDGEVILLE RD 5560 0.036 0.009 2461 RIDGEVILLE RD 5633 0.035 0.009 2541 RIDGEVILLE RD 5633 0.035 0.009 2377 RIDGEVILLE RD 5645 0.035 0.009 2233 RIDGEVILLE RD 5645 0.035 0.009 2856 RIDGEVILLE RD 5740 0.034 0.009 2760 RIDGEVILLE RD 5744 0.034 0.009 2685 RIDGEVILLE RD 5747 0.034 0.009 2711 RIDGEVILLE RD 5817 0.033 0.008 2859 RIDGEVILLE RD 6192 0.030 0.008 3015 RIDGEVILLE RD 6436 0.028 0.007 1893 RIDGEVILLE RD 6444 0.028 0.007 3247 RIDGEVILLE RD 6800 0.026 0.006 2721 RIDGEVILLE RD 6897 0.025 0.006 4231 JOHN OAKLEY RD 7489 0.022 0.005 /// VibraTech Peak Air Overpressure (Pit A): Address Distance from Blast (ft) Calculated Peak Air Overpressure Equation 5 (dBL) Calculated Peak Air Overpressure Equation 6 (dBL) 28 HENRY DANIELS RD 1128 123.4 131.4 206 BEAVER FALLS DR 1350 121.7 129.9 971 GOOSE CREEK RD 1526 120.6 128.9 115 BEAVER FALLS DR 1675 119.7 128.1 200 HENRY DANIELS RD 1784 119.1 127.6 950 GOOSE CREEK RD 1890 118.5 127.1 1238 WRENN RD 4053 111.2 120.7 2856 RIDGEVILLE RD 4058 111.2 120.7 2611 RIDGEVILLE RD 4263 110.7 120.2 2372 RIDGEVILLE RD 4275 110.7 120.2 2760 RIDGEVILLE RD 4292 110.7 120.2 3247 RIDGEVILLE RD 4305 110.6 120.2 2685 RIDGEVILLE RD 4379 110.5 120.0 2461 RIDGEVILLE RD 4400 110.4 120.0 2541 RIDGEVILLE RD 4400 110.4 120.0 3015 RIDGEVILLE RD 4417 110.4 119.9 2711 RIDGEVILLE RD 4442 110.3 119.9 2859 RIDGEVILLE RD 4560 110.1 119.7 2278 RIDGEVILLE RD 4572 110.1 119.7 2377 RIDGEVILLE RD 4650 109.9 119.5 2188 RIDGEVILLE RD 4917 109.4 119.0 2233 RIDGEVILLE RD 5000 109.2 118.9 2132 RIDGEVILLE RD 5140 109.0 118.7 4231 JOHN OAKLEY RD 5458 108.4 118.2 2592 WRENN RD 5478 108.3 118.1 2721 RIDGEVILLE RD 5701 108.0 117.8 1893 RIDGEVILLE RD 6385 106.9 116.8 /// VibraTech Peak Air Overpressure (Pit B): Address Distance from Blast (ft) Calculated Peak Air Overpressure Equation 5 (dBL) Calculated Peak Air Overpressure Equation 6 (dBL) 971 GOOSE CREEK RD 790 126.8 134.4 950 GOOSE CREEK RD 1430 121.2 129.4 2592 WRENN RD 2346 116.4 125.3 28 HENRY DANIELS RD 3150 113.6 122.8 200 HENRY DANIELS RD 3181 113.5 122.7 206 BEAVER FALLS DR 4077 111.2 120.6 115 BEAVER FALLS DR 4373 110.5 120.0 1238 WRENN RD 5095 109.0 118.7 2372 RIDGEVILLE RD 5203 108.8 118.6 2278 RIDGEVILLE RD 5290 108.7 118.4 2188 RIDGEVILLE RD 5376 108.5 118.3 2132 RIDGEVILLE RD 5500 108.3 118.1 2611 RIDGEVILLE RD 5560 108.2 118.0 2461 RIDGEVILLE RD 5633 108.1 117.9 2541 RIDGEVILLE RD 5633 108.1 117.9 2377 RIDGEVILLE RD 5645 108.1 117.9 2233 RIDGEVILLE RD 5645 108.1 117.9 2856 RIDGEVILLE RD 5740 107.9 117.7 2760 RIDGEVILLE RD 5744 107.9 117.7 2685 RIDGEVILLE RD 5747 107.9 117.7 2711 RIDGEVILLE RD 5817 107.8 117.6 2859 RIDGEVILLE RD 6192 107.2 117.1 3015 RIDGEVILLE RD 6436 106.8 116.8 1893 RIDGEVILLE RD 6444 106.8 116.8 3247 RIDGEVILLE RD 6800 106.3 116.3 2721 RIDGEVILLE RD 6897 106.1 116.2 4231 JOHN OAKLEY RD 7489 105.4 115.5 VibraTech Appendix A displays the suggested locations for vibration monitoring at the Prospect Hill location. These locations consist of a combination of permanent monitoring stations and portable seismographs. In addition to the proposed monitoring locations, Vibra-Tech recommends an additional floating portable seismograph to follow pit development to ensure coverage of any nearby structures. If you have any questions regarding this matter, please do not hesitate to contact our office. Respectfully submitted, VIBRA-TECH, INC. Andrew Coil Operations Manager, SC Chuck Jaworski Area Manager, TN Vibra-Tech, Inc., shall not be liable for any claims of tangible property damage where such damage is not solely, directly, and physically caused by Vibra-Tech, Inc. Additionally, Vibra-Tech, Inc., shall not be liable, in whole or in part, for any claims of tangible property damage brought by or on behalf of third -party claimants. VibraTech Appendix A Map of Carolina Sunrock's proposed Prospect Hill Site. Includes surrounding nearby addresses, suggested seismograph placements, pit boundaries, initial blasting zone, and distance scaling from pit boundaries.