2018 IDEAS2 Awards Brochure - 55

Ruby+Associates

components into large, self-supporting sections. Hillsdale was
very familiar with this method, having used it successfully on
numerous complex power plant projects.
The largest lifts on the project, weighing up to 700 tons, were
the outer box trusses. Each of these lifts was accomplished using
four large mobile cranes. Ruby designed special lifting frames to
ensure that loads were equally shared by the cranes throughout
each lift. Ruby designed and produced shop fabrication drawings
and developed load testing requirements for the lifting frames,
each weighing only 17.5 tons but capable of safely lifting 350 tons.
In addition to the four-crane outer box truss lifts, modular
pre-assembly necessitated 25 additional multi-crane lifts, each
carefully planned to ensure sufficient crane clearance and capacity-and above all, safety. Ruby's erection scheme also used the
permanent structural cables to support portions of the structure
during construction. The firm developed drawings addressing
cable installation sequencing and tensioning, and designed an
apparatus capable of applying more than 600 tons of pretension
to each cable.
One of the project's most complex lift sequences involved the
installation of a portion of the inner sideline box truss, two roof
modules and the 300-ft-long sideline cable, using three mobile
cranes. Each of the cranes performed multiple operations during the sequence. The initial length of the sideline cable was
precisely calculated to ensure that the cantilevered end of the
box truss was left in a super-elevated position, so that installing
subsequent canopy steel and other applied roof dead loads would
cause the cable and structure to deflect into their intended final
positions. Any final adjustments to the cable length would be
made using the adjustable cable fittings provided with the cables
and the Ruby-designed tensioning apparatus.
To predict the construction stresses and deformations, as
well as cable loading/deformation at each stage of erection, a sophisticated analytical model was prepared using SAP 2000. This
model predicted the behavior of the extremely indeterminate
structure with incredible accuracy, minimizing the number of
costly and cumbersome cable readjustments.
This project's complexity, combined with a challenging
schedule, required intense preplanning followed by daily problem solving during construction. Midway through construction, the NFL awarded Super Bowl LIV to the newly christened Hard Rock Stadium. And on September 1, 2016, less
than eight months after start of steel erection, the stadium
opened on time for the first scheduled Miami Dolphins football game of the season.
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2018 IDEAS2 Awards Brochure

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