2012-04-15_PERMIT FILE - C1981017

• Permit No: C1981017
• IBM Index Class Name: Permit File
• Doc Date: 4/15/2012
• Doc Name: Demonstration for Incomplete Highwall Reclamation
• Media Type: D
• Archive: No

Mine #4
Cohesion F. Angle Density Pore Press. Safety
Run # lb /sq.ft Degrees lb /cu.ft. Ratio Factor
#1 1040 31 108
#2 700 30 108
#3 600 35 108
#4 800 32 108
.50
. 60
.50
. 50
1.94
1.32
1.39
1.65
Run #1 uses the residual cohesion and the residual angle of
friction, which is conservative, and results in a safety factor of
1.94. Runs #2 uses a considerably lower cohesion and slightly lower
friction angle. The pore pressure ratio is also increased to 0.6
and a safety factor of 1.32 is still achieved.
Run #3 shows a higher friction angle which may occur if material
that did not pass the #4 sieve is included. The cohesion for this
case has also been lowered slightly.
The expected case for long term stability is Run #4, which results
in a safety factor of 1.65. This run is included in Appendix B.