mobilize during the timeframe requested by IHI. Once the sheet
pile material was delivered to the site, Cajun’s crew began immediately
vibrating the sheet piles into place at the Z-4001, Z-4002 and
Z-4003 basins.
It was at Basin 4003 when Cajun’s sheet pile crew came across
its first challenge. After Cajun was awarded the basin scope of work
and before mobilizing the site to install sheet piles, Georgia Power
installed an electrical transmission line tower in the footprint of
the Z-4003 First Flush Sump. This required Cajun to re-engineer
the 4003 TRS system around the newly installed tower. The Cajun
team had to strategize the process of shoring and installing sheet
piles around a tower pole and under power lines, which had zero
tolerance of being disturbed. To help solve the installation challenge,
Cajun utilized a Giken Silent Piler to install the sheet piles
under the power line, due to the equipment’s design capabilities.
The advantage of the Giken Silent Piler design is that it sits on top
of the sheet pile wall and pushes the sheet piles without vibration
or excessive noise. The use of the system eliminated the
overhead obstruction challenges and potential damage to the
previously installed tower pole. The Giken rig installed 200 linear
feet of sheets in one week. After completion of the TRS systems
at each respective basin, the heavy civil operations of the basin
scope commenced.
While the civil basin work was taking place, Cajun was awarded
additional scope to perform an exploratory test pile program for
helical piles on the site. If successful, Cajun would install helical
piles in areas where new pipe racks were required adjacent to
existing pipe racks inside the existing facility. After installation
and successful testing of the helical piles, Cajun issued the report
to IHI Engineering. The helical piles met the intended loads but
were not approved for use by the Owner. IHI informed Cajun that
Kinder Morgan would not allow helical piles to be installed on the
site due to the re-approval process timeframe by the engineer of
record to create the substitution. Therefore, designed H-piles were
required to be installed at all locations. After analyzing the work
areas and the overhead clearances at the existing pipe racks, Cajun
decided that a seven-foot H-pile was the longest section of pile that
could be installed under the existing clearances. Each pile was 77
feet in length, requiring Cajun to install 11 pile sections at each
pile location. With 13 piles required, a total of 130 full penetration
structural welds were required to combine pile sections during the
installation process. The installation duration of the H-piles was
contingent upon how fast the welders could fit up and weld two
sections of H-piles. This scope required a specialized warehouse
style forklift, box leads and a hydraulic impact hammer to install
the H-piles. The forklift would give Cajun the ability to fit into challenging
areas in the plant, where vertical headroom was an issue.
Cajun began H-pile installation on Nov. 30, 2017 and completed the
scope on Jan. 22, 2018.
Cajun completed the entire scope of work in March 2018, after
being on site for an entire year. Cajun mobilized the project to initially
install 945 piles for a six-month duration. Because of Cajun’s
dedication to safety, quality and production on site, an additional
$13,000,000 in scope was awarded to Cajun, which increased its
on-site duration from six months to one year. Cajun added value
to the project with its integrated project team approach, not only
with its other business groups and sister company, but also with
the client, owner and engineers. Even with all of the unanticipated
extra work and unforeseen delays, challenging working conditions
and congested work areas, Cajun completed the project with zero
injuries and within a timeframe that was acceptable to IHI and
Kinder Morgan. t
PROJECT SPOTLIGHT
Bathub and sheet piles at the 4001 basin
110 | EDITION 6 2019 www.piledrivers.org
/www.piledrivers.org
