Vigor (formerly Oregon Iron Works) specializes in complex
fabrication projects for dams and the civil construction
industry. We deliver quality you can trust.
BULKHEAD GATES • TAINTER GATES • FLOOD CONTROL
MECHANICAL EQUIPMENT • STRUCTURAL FABRICATION
BUILDING CRITICAL INFRASTRUCTURE
503.653.6300 SALES@VIGOR.NET
http://hydroreview.hotims.com RS #38 Visit us at HydroVision International 2017
Booth #825
consists in implementing a new intake in the
right abutment of the dam. As environment
bonus this type of turbine is fsh friendly. Te
project consists of two banks of Archimedes
screw turbines, inline and the frst bank outlet
serving as headrace for the second.
Adding the hydro component
Adding a small hydro facility to the existing
dam involved a number of structural changes:
• Cutting a 17 m by 1. 55 m window in
the cutof wall for laying out the slab at
elevation 170.9 m (founded at elevation
170.6 m);
• Replacing a section of the front right bank
dam, 17 m long, with the front intake and
headrace channel of the future arrange-
ments; and
• Using 30-m-wide portions of the existing
stilling basin, to the right bank, for the
headrace channel of the second Archimedes
screw bank. Tis section is set out from the
existing stilling basin by a routing concrete
wall with double soles, anchored by the
stilling basin apron.
Work to replace the 17 m portion of the
front right bank earth dam involved laying
the intake foundation slab, with 10 m lengths,
and the intake block. Te foundation slab is
a reinforced concrete structure between the
left and right bank abutments. Te structure
has an intermediate elevation foundation slab
at elevation 173.20 m, serving as access to
the trashracks, followed by the sluice gates
headwall, 16 m by 2. 55 m in size.
Tis solution ensures a good connection
between the existing dam front and new works
designed for the hydropower development. Te
sensitive areas needed to provide continuity are
the gap between the cutof wall and the small
hydropower plant foundation slab, as well as
the connection between the piling wall and
the revetment of the existing dam.
Te water intake is composed of piles
embedded in a slab foundation ensemble,
thus forming four openings.
Te intake is to be equipped with a coarse
trashrack ( 10 cm of rod spacing and 2. 8 m by
2 m dimensions). At the top of the racks up
to the sluice gates, a slab causeway serves for
operating followed by four manually operated
sluice gates. Te openings are closed of with
reinforced concrete headwalls up to elevation
175.75 m. Te intake assembly is incorporated
into the existing dam by routing it between
the two lines (right and left) of synthetic sheet
piling. Te slab foundation of the intake leans
on the earth dam cutof wall sealing as it raises
to the right bank closure dam by about 1. 3 m.
Te trapezoidal headrace channel is lined
with concrete slabs measuring 3. 5 m by 3. 5
m by 0.2 m. Te channel length is 75 m and
the width of the base is 14 m.
Te hydraulic circuit, after the intake,
conducts water toward the frst bank of
Archimedes screws through the headrace
channel. Te two sheet metal conduits support
the dam crest road. Te pipe is laid in the
trench created by the piles, much like in the
case of the intake. Filling the space between
their upper surface and trench sheeting with
concrete and compacted earth reinforces the
24 m pipes. Te road elevation will thus be
equal to the dam crest elevation of 176.75 m.
Six 3.545 m by 2 m gates control fow
entering the frst six-screw bank. Te gates are
activated hydraulically and some screws can be
stopped when infows fall below the design fow
