PDCA Pile Driver - 2020 Issue 1
Hudson River Park Pier 26, New York City
RISE ABOVE THE ORDINARY
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Mueser Rutledge Consulting Engineers New York City | Washington, DC
Unfavorable soil conditions
Sealevel Construction was prepared to take on the challenges of
South Louisiana’s unfavorable soil conditions. The project was
located in a marsh area composed of grassy vegetation that continually
holds stagnant water. These marsh areas are prone to coastal
erosion and subsidence or sinking land. Due to the weight of these
saturated soils, the mud and sediment naturally sink, contributing
to Louisiana’s rapid coastal wetlands land loss.
It came as little surprise to the Sealevel team that the first challenge
would be how to deal with the geological nature of the project’s
location.
“Due to this saturated soil type, we had to install 161,800 linear
feet of vertical and horizontal wick drains, which act as a pathway
designed to drain water from saturated soils. The wick drains
would accelerate the compression and stability of the existing soils
prior to the construction of levees,” said Lane.
Following the installation of the wick drains, two 300-ft.
by 200-ft. solid earthen levees were constructed on top of the
wick drains.
“The base elevation was -2.0; the levees were constructed to an
elevation of +13.00,” explained Lane. “After the initial construction
of the levees, a six-month settlement period was required due to
the likelihood of the soils sinking. Upon the completion of the six
months, the north levee settlement exceeded eight feet, while the
south levee settlement exceeded six feet. Although some subsidence
was anticipated, these amounts were well beyond expectations.
To compensate for the excessive settlement, an additional
30,000 cubic yards of material beyond the plan quantities was
barged in and placed. The levees were then reconstructed to an
elevation of +13.00 feet.”
Jacket structure installation
The next step of this impressive project was to install the jacket
structures. Prior to installation, both 190-ton jacket structures
were fabricated in Harvey, La. Upon completion of the fabrication
and coating, the jackets were placed on two 35-ft. by 195-ft. deck
barges and transported to the site.
“A heavy lift specialist was contracted to mobilize a 600-ton stiff
leg crane to set the jackets in their final location,” said Lane. “Due
to extensive planning and innovative falsework, they were able
to set and secure the jackets safely and efficiently. Once secured,
our team began the process of installing large-diameter pipe piles
within the jackets to permanently support and brace the structure.”
The large-diameter steel pipe piles included two 84-in. by 200-
ft.; six 72-in. by 180-ft.; two 48-in. by 190-ft.; and eight 36-in. by 200-
ft. battered piles.
“A big challenge for us was driving the 1.5:1 batter piles within
the jacket legs,” said Lane. “A special set of pile leads were designed
to have an internal winch and special rigging with a spreader bar.
This allowed us to hoist the pile and leads in a single pick, maintaining
the proper 1.5:1 batter. The internal winch would control
the hammer and was operated remotely independent of the
crane operator.”
Following the jacket pile installation, a critical cost and timesaving
measure was performed. The original plan called for
Sealevel to drive temporary piles and build a trestle system in
PROJECT SPOTLIGHT
APF Jet Filter
Weep Hole
Filtration System
Model JF-50000
NEW
Sheet Pile
Connector
Timber Uplift
Connector Galvanized
Model TC-7612
Provides tension
capacity of 12 tons
Box 1264 Clifton, NJ 07012-1264
NEW
Tel. 973-773-8400/800-526-9047 / Fax. 973-773-8442
Email: apf@associatedpile.com Website: www.associatedpile.com
66 | ISSUE 2 2020 www.piledrivers.org
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