Question: Coal is mined in two seams that are shown in the sketch. Mining is full seam height in both seams. Entries are 24 ft wide

Coal is mined in two seams that are shown in the sketch. Mining is full seam height in both seams. Entries are 24 ft wide (7.3 m).With reference to the stratigraphic column and rock properties in the sketch, determine for the lower seam:

(a) The safety factor with respect to tension of the immediate roof layer over the entries, and

(b) The second roof layer,

(c) A reasonable bolting plan using the dead weight load approach. Include (i) bolt length, (ii) nominal diameter, (iii) steel grade, and (iv)spacing.

Co-103 psi (MPa) To-102 psi (MPa) E-106 Rock type y-pef (kNim) h-ft

Co-103 psi (MPa) To-102 psi (MPa) E-106 Rock type y-pef (kNim) h-ft (m) psi (GPa) I Over-burden 144.0 (22.8) 1.70 (I1.7) 0.25 1.00 (6.9) 148.2 (23.4) 3.00 (20.7) 0.20 19.0 (131) 0.50 (0.34) 8.50 (5.86) 1694 (516) 1,714 (522) 2 Massive sandstone 3 Coal 4 Layered 0.30 3.50 (24. 1) 1.30 (0.89) 1719 (524) 7.00 (4.83) 1,741 (531) 75.0 (11.9) 0.35 (2.4) 149.5 (23.7) 1.50 (10.3) 0.10 17.5 (120) sandstone 5 Massive 8.50 (5.86) 1,744 (532) 148.2 (23.4) 3.00 (20.7) 0.20 19.0 (131) sandstone 6 Sandy shale 7 Coal 170.0 (26.9) 4.50 (31.0) 0.10 75.0 (11.9) 0.35 (2.4) 148.2 (23.4) 3.50 (24.1) 0.20 15.0 (103) 3.50 (24.1) 19.5 (134) 10.0 (6.90) 1.30 (0.89) 10.0 (6.90) 1,747 (533) 1754 (535) 1778 (542) 0.30 8 Massive sandstone 9 Layered sandstone 149.5 (23.7) 17.5 (120) 7.00 (4.83) 1.50 (10.3) 0.10 2.250 (686) Panels Outcrop Panels Mains Sub-mains

Step by Step Solution

3.40 Rating (163 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock

Given 2seam coal mine mining full height 24ft wide entries stratigraphic column rock properties 1719 ... View full answer

blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Document Format (1 attachment)

Word file Icon

26-E-G-R (225).docx

120 KBs Word File

Students Have Also Explored These Related Geological Engineering Questions!