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TABLE A - V <br />E -SEAM AUGER SPACING AND EXTRACTION RATIOS <br /> TYPE AND SIZE OF AUGER <br />Analysis Seam Factor of Safe ,Penetration and Overburden Conditions Circular 5 -Foot Diameter Circular 6 - Fcot Diameter Rectan ular 13 -Foot Width <br />Location Thickness Type Auger Bedrock Depth Spoil Depth W W/D Extraction W W/D 6ctraction W W/D Extraction <br /> i) PeneVation 8 max ft max ft in °,6 in % rin) <br />North Wall Variable <br />7 6.1 2.0 0 to 300 240 0 53 0.88 34.2 64 0.69 40.9 138 2.05 48.7 <br /> 6.1 1.5 500 240 170 76 1.27 28.4 91 1.26 34.1 197 2.93 40.6 <br />West Wall Variable <br />6 6.1 2.0 0 to 300 240 0 53 0.88 34.2 64 0.89 40.9 136 2.05 46.7 <br /> 6.1 1.5 500 425 0 99 1.65 24.3 120 1.67 29.0 257 3.82 34.7 <br />East Wall Variable <br />8 6.1 2.0 0 to 300 430 0 312 51 .9 10.4 374 5.19 12.5 610 12.05 14.8 <br /> 6.1 1.5 500 480 0 312 51.9 10.4 374 5.19 12.5 610 12.05 14.8 <br /> Note: 480 feet ex ceeds recom mended maximu m overburde n, refer to report <br />NOTES: <br />1. Analysis Location, refer to Fig. A-2 <br />2. Factor of Safety conditions (average web stress). <br />Variable -Indicates overburden depth increases with depth of auger penetration (Fig. A-3). <br />- Factor of Safety is a minimum of 2.0 at face, and 1 .5 at maximum auger penetration. <br />Uniform -Indicates uniform, maximum overburden depths were used, FS minimum of 2. <br />3. W -minimum web width recommended (in.). Minimum 42 in. for s tt. dia.; 48 in. for 7 tt. dia.; and W/D > 1.O for rectangular. <br />4. W/D indicates approximate width to height ration of web. Minimum Of 0.57 for circular and 1.0 for rectangular. <br />5. Circular extraction ratios were calculated based upon full seam thickness and exact auger diameter. <br />6. Rectangular extraction ratios were based upon an auger height equal to seam thickness minus 6 inches. <br />7. Between 300 and 500 foot au er netration, inter olation can be used to detemine web width <br />