shall be stiff enough to prevent damage to the fresh RCC from elastic
deflection and rebound while compaction is being accomplished. The forms
shall not be removed until the RCC has gained sufficient strength to be
self supporting (estimated to be 90 days) and not until at least 10 m 40
feet of RCC has been placed above the gallery ceiling.]
3.8.3
[Noncementing Fill Method
The gallery section may be constructed by placing a noncementitious fill in
the cross-sectional area where the gallery is to be located, compacting it
at the same time that the adjacent RCC is compacted, and later removing the
fill. Details of how this procedure will be followed, what the
noncementitious will consist of, how the fill will be removed later, and
how the gallery doors will be set shall be submitted for review and comment
in accordance with paragraph SUBMITTAL. To form the outline of the
gallery, braced partitions (or forms) shall be placed along the perimeter
of the gallery section between the RCC and non-cementitious fill. Separate
partitions (or forms) shall be installed for each lift, shall be of such
size and configuration, and be positioned on the previous lift's partitions
(or forms) to ultimately form the gallery section. The braced partitions
shall be removed during the excavation process. Alignment of partitions
(or forms) shall not result in offsets and irregularities that exceed
construction tolerances specified in paragraph CONSTRUCTION TOLERANCES.
The noncementitious fill material may be one or more of the standard RCC
aggregates or any other approved fill material, without portland cement or
pozzolan; however, nominal maximum-size aggregate shall not exceed 19.0 mm
(3/4 inch). Excavation of the gallery fill shall not start until the RCC
has gained sufficient strength to be self supporting (a minimum of 30 days)
and until at least 10 m 35 feet of RCC has been placed above the gallery
section. As soon as the strength and cover requirements have been met,
removal of the gallery shall begin. The excavated fill material shall be
disposed of in an approved manner.]
3.9
[SPILLWAY CONSTRUCTION]
3.9.1
[Spillway Chute and Ogee Section
The spillway floor shall be constructed as shown. The drawings are based
on a design whereby the spillway is constructed at the same time and rate
as used in placement of each RCC lift. The same technology and
construction procedures as used in the construction of the vertical
upstream face shall be used. The major difference being, instead of
placing conventional concrete for the floor against vertical cantilevered
forms, conventional concrete will be placed against sloping cantilevered
forms to form the spillway chute. The design and engineering of the
formwork, as well as its construction and methods of maintaining
tolerances, etc., shall be the responsibility of the Contractor. The
formwork shall be designed for loads, lateral pressures, and allowable
stresses in accordance with Chapter 1 of ACI 347R. Forms shall be of
sufficient strength to withstand the pressure resulting from placement and
vibration of the concrete and shall have sufficient rigidity to maintain
specified tolerances. Extreme care shall be taken to prevent the
occurrence of any permanent openwork, honeycombing, or voids at the
conventional concrete/RCC interface, or next to the forms. The
Contractor's construction techniques shall be satisfactorily demonstrated
during placement of the test section. The unformed portion of the spillway
will be finished by placing concrete slightly above grade and striking off
to grade by accurate screeding. The surface shall be finished as specified
in paragraph FLOAT FINISH.]
SECTION 03701
Page 57
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