Construction Today - November 2017 - 53
ing. "We've never expanded a garage in this fashion exactly,"
Grant adds. "We've added onto existing structures, but it was
always a horizontal addition to the side of the garage."
ARB Structures was a natural choice for the project because it
has a longstanding relationship with McCarthy Cook & Co. The
company built the original parking deck at The MET in 2001 and
completed another project for the developer in 2014 in San Diego.
Supporting the weight of the additional two levels meant
numerous modifications and strengthening of the existing
structure. ARB worked with International Parking Design, an
architectural firm, and Culp and Tanner, a structural engineer,
who both specialize in parking garages, to create a constructible
design that fit the visual style of the office campus. "We do a lot
of work with them," Grant says. "There was initial upfront design
concept meetings [to determine] how we go about this, how
do we make this work, how do we 'punch' through the existing
structure and how do we handle the additional the additional
exiting including adding an elevator."
Several steps were taken to increase the existing parking structure's strength. Thirty columns were added to the interior of the
garage and another 30 to the exterior to add support and create a
new façade. ARB further strengthened the structure by wrapping
beams and columns in the existing structure with carbon fiber,
bringing it up to current building code requirements. ARB's own
in-house crews completed all of the structural concrete work
involved in the retrofit.
Finally, ARB used a low-profile rig to get under the existing
parking deck and drill and install 212 micropiles, 10-inch
diameter rods that underpin the foundation and provide
structural support. "In this situation we had to put in micropiles because you can't get a normal pile rig under the existing
deck," Grant says.
Construction began in February and is on pace to be finished
by mid-December. The final weeks of work will see the installation of an elevator, stairwell, plasterwork, painting and a roof
canopy for covered parking on the top deck. Most of the struc-
CHRIS SAN PAOLO
ARB Structures added
columns to the garage to
support vertical expansion.
NOVEMBER 2017 CONSTRUCTION-TODAY.COM