PERMFILE116326

• Permit No: C1984063
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: APPENDIX M SUBSIDENCE PREDICTION AT THE EASTSIDE COAL COMPANY
• Media Type: D
• Archive: No

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3.2.1 Influence of seam inclinatirn
Angles of draw in inclined warts influence the subsidence and
strain lines as shown in Figure 9. In our case, the E seam has a
dip of 56 degrees which must be taken into consideration. Acoor:3ing
to the liandboc~c the limit angles vary with reference to Graph No. 8
(p. 16). Figure 10 shows the graph and Table 5 bring the
corrected values of limit angles.
3.3 Subsidence calculations
The following assumption were made:
A partial extraction of the E seam is ass~:uc,d. Tnis reau~-rrs
• modification of the mining height of the seam. The mining height of
6.67 m multiplied by the extraction ratio of 0.5 and divided n,~ :he
bulking ratio of 1 .3 gives the corrected mining ttPiyhi vi " _'~b
meters. 'Phis height has been taken into calculation (see Twle_ e
aryl 8 ) .
The following parameters sere used for the subsidence predi~-
tion (Figure 11 ).
a) The length of the panel for subsidence above
the section A-A, 1 = 4,000 fcnet (1,200 m 1,
and above the Section B-B, 1 2,000 feet (6Ut m).
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