Both seams of Problem 5.24 are mined by the long wall method. There are five main entries

Question:

Both seams of Problem 5.24 are mined by the long wall method. There are five main entries and sub-main entries used for development in both seams. A three entry system is used for panel development. The sub-main entries are at right angles to the mains, while the panel entries are at right angles to the sub-main entries. Show in vertical section a favorable alignment

(a) Of the main entries and

(b) Of the panel entries. A system of steeply dipping lineaments ("joints") in the region strikes due north.

(c) Average spacing is 25 ft (7.6 m). Is the mine layout favorably oriented with respect to ground control consequences associated with the joints? Defend youranswer.