2016-07-14_PERMIT FILE - M2016010 ‎(4)‎

• Permit No: M2016010
• IBM Index Class Name: Permit File
• Doc Date: 7/14/2016
• Doc Name: Adequacy Review Response
• From: Transit-Mix Concrete Co.
• To: DRMS
• Email Name: AME
• Media Type: D
• Archive: No

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Transit Mix Concrete Co.
Description Review
The Geotechnical Assessment was based on seven (7) boreholes completed by
Norwest Corporation (Norwest) and six (6) boreholes completed during a Correct
previous site investigation by another company.
Granite and granite composites are the most common rock types within the Correct
proposed quarry and pit wall locations.
The rock mass was characterized using the 1989 version of the Rock Mass Rating
System. Points were assigned using the following categories; Uniaxial Correct
Compressive Strength(UCS),Rock Quality Designation(RQD),Discontinuities
Spacing,Discontinuities Condition and Groundwater Conditions.
Groundwater levels were not identified during drilling due to the use of drilling Correct
mud.
Stability analysis models were performed assuming saturated groundwater Correct
conditions.
The overall stability analysis was performed for five(5)cross-sections at various Correct
wall heights and orientations.
A bench stability analysis was performed for each rock type and condition for a Correct
40 foot bench height at a 2V:1H slope.
The geotechnical analysis was performed by Norwest using GeoStudio software Correct
SLOPE/W Version 8.4.
The wall heights used in the overall analysis varied from 275 feet to 410 feet. Correct
The proposed bench dimensions are forty(40)feet in height and twenty(20)feet Correct. (bench height is 40 feet and
m width. catch bench width is 20 feet)
The bench highwall angle was designed at 63 degrees,2V:IH. Correct. (the author assumes this is
referring to bench face angle)
A Factor of Safety of 1.3 for Static and 1.0 for Pseudo-Static Conditions design Correct
criteria was used for the bench scale slope analysis.
The overall highwall angle was designed at 45 degrees, 1H:IV. Correct
A Factor of Safety of 1.5 for Static and 1.0 for Pseudo-Static Conditions design Correction:A factor of safety of 1.5 for
criteria was used for the overall slope analysis. static and 1.1 for pseudo-static was
used for overall slope stability
Clarification:The maximum capacity
The TS1 - Topsoil Stockpile facility will contain 317,000 bank cubic yards of of TS1 is 250,000 bank cubic yards
topsoil. (bcy). The volume within TS 1 will
vary due to progressive reclamation but
will not exceed 250,000 bcy.
Correct. (Stockpile is constructed at
The F 1 -Fines/Overburden Stockpile will be constructed with 3H:1 V slopes. overall slope of 3H:1 V with individual
benches originally at angle of repose)
Hitch Rack Ranch Quarry(M-2016-010)
Response to Comments—July 14, 2016