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SURFACE BLASTING WORK <br />Task description: Cast Blast Z -Pit (Highwall) <br />Site: Trapper Mine Permit Action: MT7 <br />PROJECT IDENTIFICATION <br />Task #: 021 State: Colorado <br />Date: 6/12/2015 County: Moffat <br />User: JLE <br />Agency or organization name: DRMS <br />BLAST AREA DIMENSIONS <br />Permit/Job#: C1981010 <br />Abbreviation: None <br />Filename: C081-021 <br />OUANTITY I UNIT <br />Blast Area Configuration: <br />Wedge-shaped mass (highwall reduction using balanced cut/fill) <br />Blasting Method Description: <br />Cast blast (fragmentation + lateral movement) <br />Highwall or Bench Face Angle: <br />0.71 <br />h:lv <br />Regraded Slope Angle: <br />2.00 <br />h:lv <br />Highwall or Bench Length: <br />542 <br />feet <br />Highwall or Bench Width: <br />50 <br />feet <br />Highwall or Bench Height: <br />150.0 <br />feet <br />Depth to Base of Cut at Highwall: <br />25.0 <br />feet <br />BLAST AREA VOLUMES <br />QUANTITY UNIT <br />Total Volume of Dimensional Mass to be Shot: 8,092 cubic yards <br />Blast Volume to Subdrill Grade and Blast Pattern Lines: 5,425 cubic yards <br />Blast Volume to Finish Grade and Blast Pattern Lines: 5,425 cubic yards <br />Remaining Volume Required to be Re -Shot or Ripped: 2,668 cubic yards <br />BLAST AREA DESIGN <br />QUANTITY <br />UNIT <br />Recommended Blasthole Diameter: <br />3.333 <br />inches <br />Selected Blasthole Diameter: <br />9.000 <br />inches <br />Subdrilling Allowance: <br />0.0 <br />feet <br />Blasthole Depth: <br />12.4 <br />feet <br />Density of Rock: <br />Cast blasting (ANFO Basis) <br />rock density <br />Burden to Charge Diameter Ratio: <br />20 <br />times diameter <br />Burden: <br />15.0 <br />feet <br />Spacing to Burden Ratio: <br />1.1 <br />times burden <br />Spacing: <br />17.0 <br />feet <br />Cubic Yards of Rock per Blasthole: <br />87.50 <br />cubic yards <br />Powder Factor Description: <br />Cast blasting <br />rock strength <br />Powder Factor: <br />2.150 <br />pounds/cu. yd. <br />Density of Blasting Agent: <br />0.85 <br />grams/cc <br />Quantity of Explosives per Blasthole: <br />188.12 <br />POUNDS <br />Height of Powder Column: <br />8.02 <br />feet <br />Height of Stemming per Blasthole: <br />4.35 <br />feet <br />Stemming to Burden Ratio: <br />0.29 <br />times burden <br />Quantity of Stemming per Blasthole: <br />0.0712 <br />cubic yards <br />Number of Rows: <br />2 <br />rows <br />Number of Blastholes per Row: <br />31 <br />holes per row <br />Total Number of Blastholes: <br />62 <br />holes <br />Total Length of all Blastholes: <br />767 <br />feet <br />