APPCOR10180

• Permit No: C1980002
• IBM Index Class Name: Application Correspondence
• Doc Date: 8/30/1995
• Doc Name: OC 2 COAL MINE PN C-80-002 PRIOR EXPERIENCE
• Media Type: D
• Archive: No

STATE OF COLORADO
Roy Romer, Governor
DEPARTMENT OF NATURAL RESOURCES
MINED LAND RECLAMATION DIVISION
FRED R. BANTA, Dlr~etor
RF~F~~~D
A
DATE: October 25, 1989
T0: Randy Price
FROM: Jim Pendleton
RE: Fruita Mi.rltf Recl lion
Pursuant to your request, I have
Fruita #1 Rock Fill" included as
Reclamation Permit of the Fruita
prepared by Greg Lewicki, Colo.
computer slope stability routine
of Kentucky, named "REAME". Thi
widely known and accepted within
~.
UG 3 ~ 199,5
I ~ ~/$- V l Sl on 01 M~nera~s ~ ~.QOiopy.
Sion - Fruita #1 Bench Stability
reviewed the "Slope Stability analysis of the
Appendix A within the "Application for
Nine Complex..." This stability analysis was
.E. #22804. Mr. Lewicki's analysis uses a
developed by Dr. Yang Huang of the University
computer simulation modeling routine is
the Civil EnaineerinD discipline.
Material samples were collected
laboratory analysis. The actual
used to prepare samples for labor
strength value of 0 cohesion and
were determined at the field dens
conversion technique was utilized
within the fill, resulting in an
While this is an empirical correc
its use by performing sensitivity
strength values.
om the fill by Mr. Lewicki and subjected to
bserved field material density values were
tory shear strength testing. A shear
n angle of internal friction of 37 de_arees
ty of 116 lbs.!cu.ft. Dr. Huana's
(to compensate for oversized durable material
fective shear strength of 41 decrees.
~on technique, Mr. Lewicki compensated for
tSVpe calculations using a range of shear
The slope stability analysis determi ed that at a reduced facial anal e. of
2.Oh:1.Ov, the minimum projected s1o~g stability factor of safety encountered
for a failure slice of more than 5 feSt in thickeeas fi?~ When Lsinq the
.dDserved lab value of 37 decrees, the tnimuln f'afiety~atc{'or• is 1.54. Placing
the modeled plane of failure deeper in~the fill results in.progressively
iTtcreasing factors of safety.
Im my opinion, Mr. Lewicki has done a coirmendable job of analyzinD the Fruita
#1 Rock Fill's slope stability. His tech~ique is-empirically based, but his
tpDroach is reasonable and conservative i his choi.t:e of--material strength
values. I recolmlend that we accept his an lysis-as submitted. Further, l
ret:gmmend that we approve the proposed redu~tion:.in facial slope ahgie of the
Frtjita #1 Rock Fi11 to 2.Oh:1.Ov. The analysts projects that an acceptable
s]ape safety factor in excess of the required\:5 will be achieved with the
pr»posed configuration.
215 Centennial Building, 1313 Sherman Street Denver, Colorado 80203.2273 Tel. [phone]