“The challenge with this project – in addition to working in a
riverbed – is that 64 of these piles need to be installed under the
existing bridge deck in a ‘low headroom’ condition,” said Bird. “Due
to having 23 feet of headroom, this requires the steel beams to be
installed by being driven incrementally in 15 feet to 20 feet pieces
and spliced on the job site.”
Equipment and challenges
Due to the particulars of this project and limited access, Forefront
Deep Foundations moved forward with utilizing a variety of hammers
to install piles most efficiently in different access conditions.
These included the following:
• Crane: 90-ton rough terrain hydraulic crane
• Forklifts: 12,000 lb. forklift and a 20,000 lb. forklift
• Hammers: Diesel impact hammer – APE D-36 jammer with
26-inch swinging leads; Vibratory hammers – APE 64 X vibratory
hammer and a J&M 22-30 vibratory hammer; and a hydraulic
impact hammer – APE 6-2 hydraulic impact hammer
“The project has 256 HP 14x117 steel beam piles totaling 14,000
linear feet,” said Bird. “That is 2.65 miles of piles!”
This project has also had its share of challenges, which required
Forefront Deep Foundations to utilize advanced techniques
and methods.
“For example, this project is located in an active riverbed, which
required the team to utilize environmentally safe, biodegradable
hydraulic fluid to avoid any contamination if a hose should break,
etc.,” said Bird.
The crew is also working with limited access between bridges,
which involves coming up with innovative ways to access pile
installation locations that are between the two existing bridges.
“The solution was to utilize a 90-ton RT hydraulic truck crane due
to its smaller footprint than a conventional truck or crawler crane,”
said Bird. “The piles were ‘established’ using a vibratory hammer, and
then driven to the final elevation using an APE D-36 impact hammer.”
Additionally, piles are being driven underneath the existing
bridge deck.
PROJECT SPOTLIGHT
Forefront used a 90-ton hydro crane to access pile locations that were located between the two existing bridges due to extremely limited access
76 | ISSUE 1 2021 www.piledrivers.org
/www.piledrivers.org
