“Once we put the fixed roof on and tinted
it, there was not enough sunlight energy
to grow grass so we decided to go with
a retractable field option”
David Manica, president and owner, Manica Architecture
“At the tip of all of the cantilevered trusses is the
compression ring, and this is the key element as from
here all the cable net structure is strung from. The
oculus is formed in two layers of cables creating the
profile of lens shape separated by struts. What this
does is give us the lightest possible structure
supporting all the ETFE. It’s very airy and if this was
done using a traditional steel truss system it would
feel like you’re inside a cage,” says Nichols.
Meanwhile, the expansive peristyle at the north
end of the stadium is inspired from the team’s days at
the LA Coliseum and when they realized the view it
would have facing it, it was a no-brainer to install the
dramatic stacking glass doors there.
“When that design was shared initially, nobody
thought we would be able to achieve that 200ft-wide
opening because not only is it curved in one
direction, it is sloping downward as well. It took quite
a lot of structural engineering creativity to make it
ALLEGIANT STADIUM
TIGHT SCHEDULE
The 31-month schedule to turn around one of the most bar-raising sports
and entertainment venues ever built required a constant flow of activity,
with efficient systems put in place to keep tasks advancing. Initiatives were
employed such as setting up a dedicated concrete plant on-site to save time
on transporting in the 125,000 cubic yards of concrete for the foundations.
Elsewhere, the bowl was built using precast concrete where risers were
created off-site and assembled around the clock on site.
“A lot of the materials for the stadium were built and shipped from overseas
to a fabrication facility in Phoenix, Arizona, where the units were preassembled
in large sections and delivered to the job site. The curtain wall
which is comprised of 2,400 panel sets went up pretty quickly because of
this, which was critical to accommodate our tight schedule as at this stage,”
explains Eric Grenz at Mortenson. All the thousands of workers were also in
tight synchronization with
digital modeling software
helping to keep track of the
project’s logistics.
“From the very beginning,
this project was setup that all
disciplines would be working
in Revit. There were multiple
models, not only design
models that we managed, but
the structural engineers had
theirs, and there were
mechanical models, and
plumbing, and electric etc.
All of this lived in the cloud
that way we all had the
current status of the
development we could
reference. We would use
Revizto to integrate all those
models to review and
develop our clash detection
and for the logistics of the
build, we coordinated with all
the building engineers,
design assist partners, and
subcontractors who were
working in a virtual
environment using BIM,”
describes David Graue,
associate vice president at
HNTB, and technical director
on the project.
work. We assumed we would have to add a couple of
columns in somewhere to support it but luckily we
were able to avoid that and deliver that beauty shot,”
reveals Nichols.
However, an ETFE roof and retractable wall are not
enough to combat the desert conditions. Mark Davis
and the Raiders, who were heavily involved in final
decisions throughout the process, were adamant on
a number of non-negotiable design elements that
would carry forward the team’s history. Along with
the peristyle, was the need for the Raiders to always
play home games on natural grass turf, something
former Raiders owner and Mark’s father, Al Davis,
famously said his players would always do. Due to
the amount of tinting of the ETFE roof, this poses a
problem for growing conditions, but is solved by one
of the biggest feats of engineering on the job in the
form of a 2,000,000lb sliding field that moves on
electrically-driven wheels to the outside.
www.stadia-magazine.com June 2020 17
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