PERMFILE110064

• Permit No: C1996083A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 15 Subsidence Prediction
• Media Type: D
• Archive: Yes

TABLE 15-3
Probability of Chimney Collapse Through Overlyino Rock
(data from Grav etal, 1977)
127 cases of chimney collapse to surface over Pittsburgh Seam, documented in the field.
Height Number of Cumulative Cumulative
Class Documented Number of Percent of
Interval Chimney Chimney Chimney
(feet) Collapses Collapses Collapses
200 - 210 1 1 0.8
190 - 200 0 1 0.8
180 - 190 0 1 0.8
170 - 180 0 1 0.8
160 - 170 0 1 0.8
150 - 160 1 2 1.6
140 - 150 3 5 3.9
130 - 140 1 6 4.7
120 - 130 0 6 4.7
110-120 0 6 4.7
100-110 2 8 6.3
90 - 100 2 10 7.9
80 - 90 3 13 10.2
70 - 80 5 18 14.2
60 - 70 2 20 15.7
50 - 60 8 28 22.0
40 - 50 15 43 33.9
30 - 40 21 64 50.4
20 - 30 29 93 73.2
10 - 20 29 122 96.1
0 - 10 5 127 100.0

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