2023-08-31_ENFORCEMENT - M1982121

• Permit No: M1982121
• IBM Index Class Name: Enforcement
• Doc Date: 8/31/2023
• Doc Name: Rock Failure Analysis and Stability Report
• From: RMR Aggregates, Inc.
• To: DRMS
• Email Name: ACY
• Email Name: THM
• Media Type: D
• Archive: No

K1L D UFF RMR Aggregates, Inc.
J N ❑ E R G R O U N ❑ Rock Failure Analyses and Stabilization Report
NGIN E E R I N G,INC. Mid Continent Limestone Ouarry
KUE April 2023 field reconnaissance on the East face that indicate a tighter cluster of dip ranging from
29 to 32 degrees, all dipping to the south-southwest (192' +/-10).The steeper CGS measurement of
44 degrees is assumed to be lower on the face where the fold is steeper. The primary discontinuities
controlling rock mass stability in the slope are generally persistent and control rock mass response.
After defining the discontinuity sets, analyses for each mode of potential failure were performed. The
number of the discontinuity stereonet poles that meet the kinematic criteria of lying within the
critical zone for failure are represented on Table 1 as a percentage of the total number of
discontinuities.
Table 1. Summary Results of Kinematic
Stability Analyses for East Face— Critical
Failure Poles
Failure Mode Critical Percentage
Poles of Poles
All 4 1.33%
Wedge Intersections
Sets Only 0 0.00%
Limestone
(Bedding 0 0.00%
Planar Slide Only)
(No Limits) Mudstone
(Bedding 10 100.00%
Only)
Limestone
Planar Slide
(Bedding 0 0.00%
Only)
(Lateral
Limits) Mudstone
(Bedding 7 70.00%
Only)
Note: Failure mode numbers in table represent the percentage of total discontinuity
poles that kinematically lie within the critical zone for failure.
Based on the kinematic analyses, there is a low probability of wedge failure. The results from the
wedge stability analyses indicate a very low probability of failure.
The kinematic analyses corroborate field observations from the field reconnaissance that indicate the
primary failure mode is planar sliding along the limestone bedding planes consisting of mudstone
dipping adversely along the south-facing highwall. Wedge sliding of rock blocks occurs when the
intersection line between two discontinuities plunges in the direction of the cut face at an angle
steeper than the rock friction angle but less steep than the angle of the cut slopes (Wyllie and Mah,
20044), as seen in Photo 16. Critical intersections represent wedge geometries that satisfy frictional
'Wiley, D.C. and C.W. Mah,2004, Rock Slope Engineering,41h Edition,Spoon Press, New York, NY.
Page 5
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