A long wall panel 6,200 ft long with a face length of 820 ft is planned for a seam 1,300 ft deep and 16.5 ft thick. Mining is full seam height. Assume UK conditions apply. Find:

1 The maximum subsidence that will develop during the life of the panel.

2 The maximum subsidence after the face has progressed 520 ft.

3 The surface subsidence profile when fully developed.

4 The surface strain profile; include specific values for Et, Ec, ec.

5 The width of a barrier pillar needed to protect a ventilation shaft that serves the mine.

6 The time required to mine the panel at 7,600 tons per shift, 2 shifts per day 250 days per year.

7 The average rate of advance per day.

8 The maximum subsidence after mining four identical panels adjacent to the first panel and trough width.

9 The maximum subsidence and trough width after mining an identical panel 80 ft directly below the first panel.

10 Assuming US conditions with a subsidence factor of 0.65 and an angle of draw of 28◦ find the maximum subsidence and trough width for a single panel and for four adjacent panels.

11 Estimate the maximum tensile and compressive strains for a single panel assuming US conditions (part 10).