1994-08-19_HYDROLOGY - M1977378

• Permit No: M1977378
• IBM Index Class Name: HYDROLOGY
• Doc Date: 8/19/1994
• Doc Name: Bypass Pipe
• From: John F. Abel, Jr.
• To: Sunnyside Gold Corp
• Permit Index Doc Type: Hydrology Report
• Media Type: D
• Archive: No

�JOHN F. ABEL,JR.
MINING ENGINEER
7 79' 310 LOOKOUT VIEW COURT
GOLDEN.CO 80401
303-2794901
FAX [phone]
August 19, 1994
Mr. Larry Perino
Sunnyside Gold Corp.
P.O. Box 177
Silverton, CO 81433
Dear Larry:
As you requested I have examined the waterstop design for the
Terry Tunnel �i ass pipe with respect to its potential for loading
the airside reinforcement under the maximum possible 8, 090 lbs of
thrust. The maximum load that will be applied by the waterstop to
the downstream rebar is less than one pound. This should not
affect the ability of the bulkhead to support the nearly 5 million
pounds of design thrust on the Terry Tunnel bulkhead. The
calculations follow the presentation of the input conditions and
design assumptions.
The Terry Tunnel bypass pipe is Schedule 80 (Extra Strong)
316L Stainless Steel, nominal 6-in diameter (6. 625-in OD, 5.761-in
ID, 8.40 in cross sectional area) . The waterstop welded to the
bypass pipe 2 . 75 feet (33 inches) downstream from the thrust collar
is 0. 035-in thick, 6. 625 ID by 10. 625 OD, 316L Stainless Steel
doughnut (concentric circular ring) . The factory fabricated 316L
Stainless Steel thrust collar is 5. 5 feet (66 inches) upstream from
the airside face of the Terry Tunnel bulkhead, 3/8-inch thick with
an ID of 6. 625 inches and an OD of 10. 625 inches, welded to the
bypass pipe on both sides of the collar, as specified. The thrust
collar will support the maximum possible 8090 lb of thrust, that
would develop under the maximum 650 feet of head (280 psi) . The
purpose of positioning the thrust collar 5.5 ft from the downstream
(airside) face of the Terry Tunnel bulkhead is to transfer the
thrust from the thrust collar to the tunnel walls without applying
any additional flexural bending stress to the airside tensile
rebar.
The bypass pipe is conservatively assumed to extend
elastically when subjected to the maximum tensile thrust on the
pipe, unimpeded by any bond strength between the thrust collar and
the downstream end of the bypass pipe. The waterstop was assumed
to be a simply-supported 10. 625-inch long, one-way beam and
symmetrically loaded at 2 inches from each support (simple beam,
two equal concentrated loads symmetrically placed) . This
assumption is conservative because any load imposed on the
waterstop will actually be distributed two-ways and over the