2012-06-14_REVISION - M1981185

• Permit No: M1981185
• IBM Index Class Name: REVISION
• Doc Date: 6/14/2012
• Doc Name: TR-03 SUBMITTAL
• From: WILDCAT MINING
• To: DRMS
• Type & Sequence: TR3
• Email Name: DMC
• Media Type: D
• Archive: No

EARDON MINING INDUS I HY CONSULTANTS
TEEL LLC 18050 COUNTY ROAD G • CORTEZ. CO 81321 • 970.565.0278 • [e-mail]
June 13, 2012
Dustin Czapla
Division of Reclamation, Mining and Safety
101 South 3` Suite 301
Grand Junction, CO 81501
Page 1 of 2
RECEIVED
JUN 1 4 2012
GRAND JUNCTION FIELD OFFICE
RECLAMATION INING OF
& SAFETY
RE: Technical Revision 3, May Day Idaho Mine Complex, Permit No. M- 1981 -185, La Plata River
Bridge Renovation
Dear Mr. Czapla,
This letter and the enclosed attachments comprise Wildcat Mining Corporation's (WCM) submittal of its
3rd Technical Revision (TR3) to the May Day Idaho Mine Complex Permit No. M- 1981 -185. TR3 is
focused on renovation of the bridge crossing the La Plata River, and is being provided to DRMS in
accordance with WCM's October 11, 2011 response to Adequacy Issue No. 7 from Tim Caizer's
September 28, 2011 Memorandum to Wally Erickson.
On January 19, 2012 WCM performed geotechnical drilling of the fill material behind both bridge
abutments (drilling contractor: Enviro -Drill of Farmington, New Mexico). The drilling was logged by
WCM consultant, David McClay, P.E. The logs for each drilling location are included with this
submittal. The drilling of the west abutment, designated as BRB -01, consisted of three hollow stem auger
boreholes at the edges and center of the abutment. All three borings reached refusal at 3.0 feet from the
surface; the center borehole is represented by the BRB -01 drill log provided with this submittal. The 3
feet of augured fill above refusal consists of very dense and angular, coarse to fine sandy gravel,
classified as a well - graded gravel according to the ASTM Unified Soil Classification System (USCS)
(ASTM D2487 -11). Due to the high compaction of the fill and the shallow depth to refusal at BRB -01,
blow counts exceeded the maximum measurement of 50 blows per foot.
Drilling of the east abutment, designated as BRB -02, consisted of three hollow stem auger boreholes at
the edges and center of the abutment. The north- outside and center boreholes reached refusal at 2.0 feet,
and the south - outside borehole reached refusal at 4.0 feet; the south - outside borehole is represented by the
BRB -02 drill log provided with this submittal. The 2.0 to 4.0 feet of augured fill consisted of very dense,
silty- gravely sand classified as well - graded sand according to the USCS. Similar to BRB -01, due to the
high compaction of the fill and the shallow depths to refusal at BRB -02, blow counts exceeded the
maximum measurement of 50 blows per foot.
During Spring 2012, WCM engaged Wilson Structural Engineering (WSE) of Durango, Colorado to
assess the structural integrity of the bridge, as is, and to develop a renovation plan for the bridge in order
to safely accommodate a loaded tandem dump truck with a gross weight of 54,000 pounds. On May 24,
WSE provided WCM with a Bridge Renovation Plan, included with this submittal, specifying the
following:
1. Extension of the existing steel abutments by welding a 3/8" by 6" triangular gusset plate parallel
to the web the abutments, spanning new w 1 2x53 steel beems on the outer edges of the abutments,
then welding and bolting a 3/8 "x12" cap plate to the underside of the new steel beams where the
they rest on the welded gussets.
2. Reinforcement of the existing steel abutments by adding 3/8" web stiffners under the centerline of
each beam from the top to the bottom of each abutment, and welding and anchoring 3/8" steel
plate lying flat against the concrete footing of the abutments.