Floodwall piles
Driving the 48-inch by 175-ft. and 36-in. by 175-ft. plumb piles of
the floodwall, the Sealevel team installed four at a time in an engineered
pile template. Each pile consisted of two pieces that were
spliced in place within the template. In addition to the plumb piles,
the floodwall consisted of sixty-three 36 in. by 185 ft. battered piles.
The battered piles were then driven utilizing a batter rack template
that would support the pile in the designed 1.5:1 batter. Due
to the difficult batter of the pile, a BSP CX-85 hydraulic pile hammer
was used for pile installation.
Landing truss installation
After the cutoff wall and sheet pile cap was installed, the 40-ft.
by 190-ft. landing support truss was installed 14 feet below the
water’s surface. The 98-ton truss was hoisted with a 600-ton stiff
leg crane and lowered in place utilizing eight guide piles. With the
requirements of the seal design and barge landing area, the landing
support truss had a location tolerance of only +/-.5 inches.
This allowed Sealevel Construction to successfully install this large
structure safely and within the required project tolerances.
Following the landing truss installation came the sheet pile wall
construction. Approximately 200 total pairs of sheet piles, 81 ft.
and 76 ft. in lengths, were installed along both sides of the landing
truss to connect with the earthen levees. These sheet piles were
installed two at a time using a 230-ton crane. The completed sheet
pile wall provides approximately 750 wall feet of flood protection.
Last major milestone
The project’s last major milestone was the installation of the
barge gate. The floodgate – named in memory of Jimmy Dagate –
was built and delivered by Bollinger Shipyards. Standing 40 ft. tall
and 190 ft. wide, the automated barge gate can ballast 10 feet below
the waterline and extend up to +18 feet. The barge also has four
pipes, six feet in diameter, with a flap valve attached to each. The
flap valves allow the water levels to equalize on both the protected
and unprotected sides of the gate.
“Once the barge was situated in place, the team drove its
last pipe pile to connect it to the sheet pile wall and secure the
floodgate in its open and closed positions,” said Lane. “When not
engaged in its closed position, the barge sits on twenty 24-in. by
FALGOUT CANAL FLOOD CONTROL STRUCTURE
Contract value
• $35,476,898.00
Type of construction
• Marine heavy civil construction
• Large diameter pipe piles
• Lump sum
• Sheet piles and steel pipe piles
• Barge fabrication
Physical size of project
• 1,025 linear feet of flood protection
Structure’s features
• 25,000 linear feet of steel pipe pile
• 1,105 wall feet of steel sheet pile
• Installation of a 190-ft x 40-ft
× 28-ft steel barge gate
• Construction of two 190-ton jackets
• Construction of approximately
751 feet of steel floodwall braced
with plumb and batter piles to an
elevation of +18 feet
• To prevent future scour protection,
40,000 tons of 250 lb. rip rap was
placed in navigation channel.
• (2) 84-in × 200-ft steel pipe pile
• (6) 72-in × 180-ft steel pipe pile
• (2) 48-in × 190-ft steel pipe pile
• (8) 36-in × 200-ft battered piles
at 1.5:1 batter
• Hydraulic dredging of 40,000 cubic
yards of material
• 7-plus acres of marsh
habitat recreation
Duration of project
• 570 calendar days
Sealevel total man-hours worked
• 82,038
Percentage of work
self-performed
• 95 percent
Icons: jemastock/123RF
PROJECT SPOTLIGHT
Fully completed, the Jimmy
Dagate Flood Control
Structure – situated in the
middle of the Falgout Canal –
protects more than 100,000
people from flooding.
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