Case Studies
New-Construction Helicals Support: 70-Foot Cylindrical Storage Tower
Millington, TN
Ram Jack customer, nexAir, needed to install a new tank in their Millington
location. The tank was projected to tower at 70 feet. To successfully
install the new tank, the company would need to commission the help of
engineers to design a solid foundation. All cylindrical storage tanks
require a very specific foundation. It is required that vertical, lateral,
and overturning moment forces are addressed in the design.
PROBLEM
After being tasked with designing the foundation for nexAir’s new
tank, the Ram Jack Tennessee team, partnered with S. Gordin Structural
Design, quickly saw that the installation would call for helical piles.
Due to the height of the tank, wind would induce a significant overturning
moment, which Ram Jack would need to take into account. After calculating
all of the loads and reactions, the team of experts began designing the
optimum foundation to meet all of the load requirements.
PROPOSED SOLUTION
Once they designed the foundation, Ram Jack, headed by Keith Lusk, along
with S. Gordin Structural Design, proposed the installation of (20) 5
1⁄2" piles to be placed around the perimeter edge of the foundation.
Doing this would be to resist additional tension and compression loads
induced by the overturning moment. (16) 2 7 ⁄8” piles were
installed to resist the remainder of the vertical compression loads, providing
uncompromised support across the board. The load requirements for the
5 1⁄2" dia. piles called for 71.4 kips allowable, and 48.8
kips tension. The 2 7 ⁄8" dia. piles were installed to 32.3
kips allowable. All piles were installed to an average depth of 50-feet.
OUTCOME
The team managed to install a total of 36 piles and carry the project from
start to finish in just four days. Everything went according to plan,
and no unexpected hurdles were documented. nexAir was very pleased with
the result and the team’s commitment to completing the job within
the requested time frame. The remaining tank installation process went
smooth and error-free, with a solid foundation to support the tank.
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