Prescribe a bolting plan for entries driven 28 ft (8.5 m) wide in the lower coal seam in the sketch using the dead weight load approach. Include nominal bolt diameter, length, grade of steel, installation tension, and spacing. Support your recommendation withcalculations.

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Rock type E-106 r-pcf (kNim?) Co-psi (Mpa) Topsi (Mpa) h-ft (m) psi (Gpa) I Over-burden 2 Massive Sandstone 1694 (516) 1714 (522) 1.70 (I1.7) 3.00 (20.7) 50 (0.34) 850 (5.86) I44.0 (22.8) 148.2 (23.4) 0.25 1,000 (6.9) 19,000 (131.0) 0.20 3 Coal 4 Layered sandstone 5 Massive sandstone 6 Sandy shale 7 Coal 8 Massive sandstone 75.0 (11.9) 0.30 3,500 (24.I) 149.5 (23.6) 1.50 (10.3) 0.10 17,500 (120.7) 700 (4.83) 0.35 (2.4) 130 (0.90) 1719 (524) 1741 (531) 1744 (532) 148.2 (23.4) 3.00 (20.7) 0.20 19,000 (131.0) 850 (5.86) 170.0 (26.9) 75.0 (11.9) 148.2 (23.4) 4.50 (31.0) 0.35 (2.4) 3.50 (24.1) 0.10 0.30 15,000 (103.4) 3,500 (24.1) 19,500 (134.5) 1,000 (6.90) 1,300 (8.97) 1,000 (6.90) 1747 (533) 1754 (535) 1778 (542) 0.20 9 Layered sandstone 2250 (658) 149.5 (23.6) 1.50 (10.3) 0.10 17,500 (120.7) 700 (4.83)