1995-07-12_INSPECTION - M1977378

• Permit No: M1977378
• IBM Index Class Name: INSPECTION
• Doc Date: 7/12/1995
• Doc Name: Constr Insp
• From: John F. Abel Jr.
• To: Sunnyside Gold Corp
• Media Type: D
• Archive: No

999
C JOHN F. ABEL,JR.
MINING ENGINEER
310 LOOKOUT VIEW COURT
7 7- 379 G0303.279-4901
Y ` FAX 27"163
vJuly 12, 1995
r. Larry Perino
,Mr.
Gold Corp.
P.O. Box 177
Silverton, CO 81433
Dear Larry:
This letter report covers my inspection of the construction
and filling of the American Tunnel bulkhead form on July 6th and
7th, 1995. The potential for 1550 feet of head on the American
Tunnel bulkhead and the impact the unplanned release of the
impounded water necessitated careful inspection. I arrived at the
bulkhead location at 6:50 a.m. on July 6, 1995. An access window
was available for entry and inspection. The rebar that were
temporarily tied beside and below the window for final access and
cleaning were permanently tied into their design positions later
when filling of the form approached the level of the access window.
We entered the form and performed the pre-filling inspection and
exited the form at 7:45 a.m. I inspected 1) the plywood facing of
the bulkhead form faces; 2) the water-side shrinkage and
temperature rebar cage for spacing and location; 3) the soundness
and irregularities of the exposed rock on the back, ribs and floor;
4) the poured cylindrical concrete pedestal supports for the
12-inch diameter Schedule 80 Stainless Steel pipe; 5) the three
combination pipe joints and thrust collars and the two combination
water stops and thrust collars on the 12-inch stainless pipe; 6)
the 1-inch diameter stainless steel pressure sensing and sampling
pipe, complete with its three water stops and 7) the air-side
tensile reinforcement for size, spacing and location. After
exiting the form we examined the exterior downstream bulkhead form
face, including the form bracing and the stainless steel valve and
pipe set up. We also inspected the pipe outlet and observed that
the pipe was discharging at about half full.
The rebar cages were constructed as designed (March 10, 1993
report, page 18-27) . The #10 bars had been tied into the air-side
cage at approximately 4 inches from the water-side bulkhead form.
This exceeded the required minimum 3.5 inches. The most important
#10 tension bars were tied into the required cage on 7-inch
centers, as specified, with the exception of the three vertical and
two horizontal bars that had not been tied into the final position
in order for final access, inspection, cleaning and vacuuming up
the few gallons of water ponded in the low spot approximately 4
feet from the water-side face. The air-side rebar cage was also
approximately 4 inches from the bulkhead form. The spacing had
been increased 1/2 inch to allow for the marking of the rebar