1995-06-20_REVISION - M1977378

• Permit No: M1977378
• IBM Index Class Name: REVISION
• Doc Date: 6/20/1995
• Doc Name: American Tunnel Bulkhead Wall Irregularity
• From: Sunnyside Gold Corp
• To: DMG
• Type & Sequence: TR14
• Media Type: D
• Archive: No

1111111111111111111
9
. :rIVE D
SUNNYSIDE GOLD CORPORATION -'�JUN 2
AN ECHO 8AY COMPANY 199a
P.O. Box 177 .Silverton, CO 81433 ;CIS&GBUIU
Phone [phone] .Telecopy [phone] f� 9y
June 19 , 1995
Allen Sorenson, Reclamation Specialist
Department of Natural Resources
Division of Minerals and Geology
1313 Sherman Street , Room 215
Denver , Colorado 80203
RE: Feri
' le No . M77-378 , T14
can Tunnel Bulkhead wall irregularity
Dear Mr . Sorenson:
The design assumption that enough perimeter area irregularity
exists at each of the bulkhead sites to prevent bulkhead failure by
thrust is to be confirmed prior to pouring of the bulkhead or a
design for shear pins is to be submitted to the Division if the
design assumption cannot be confirmed . Because of the relatively
small irregularity (0 . 15" ) and quantity (10o of the perimeter area)
of intact rock irregularities required , it would be very difficult
to verify if a bulkhead site was marginal in respect to these
design assumptions. The American Tunnel Bulkhead site is not
marginal . Attached are x-sections, long sections and plan sections
to provide documentation to demonstrate that the design assumptions
are valid . The following estimation of wall irregularity
percentage is similar to that provided for the F-L Brenneman
Secondary Bulkhead , F-L Brenneman Primary Bulkhead , B-L Brenneman
Secondary Bulkhead , B-L Brenneman Primary Bulkhead and Terry Tunnel
Bulkhead .
The x-sections, plan-sections and long-sections show the widening
and narrowing of the tunnel resulting from the different rounds
taken to drive this length of tunnel. They also show a slight turn
in the tunnel that will further serve to anchor the bulkhead . The
bulkhead will be adequately anchored against thrust movement .