This exciting Design-Build project
called for a new 1,200’ long pedestrian bridge/ramp over Northside Drive at the new Mercedes-Benz Stadium for the City of Atlanta. It is designed to
improve interconnectivity between the Westside neighborhoods, downtown Atlanta,
and MARTA by safely providing pedestrian access over Northside Drive while
improving traffic flow, especially around events like Atlanta Falcons and
Atlanta United games. This was an essential infrastructure piece that fixes a
once dangerous barrier preventing easy passage from the stadium, the new Home Depot Backyard community space and downtown points - to mass transit and parking facilities.
The Serpentine bridge curls at each end and stretches
prominently across Atlanta’s Northside Drive connecting the Mercedes Stadium to
the neighborhood, Marta station and nearby parking. The pedestrian bridge’s
architectural cladding system is a composition of solid and perforated diamond
shaped aluminum panels enclosing the bridge spans. During the day the cladding
enclosure casts decorative shadow/light patterns
onto the bridge deck while at night, light permeates the cladding, emitting a
soft glow. In addition, you will find several unique diamond patterns
implemented throughout the project. The various diamond patterns throughout the
project create a cohesive aesthetic appearance relating to the stadium’s
architectural language. The mechanically stabilized earth (MSE) and parapet
walls also contain these diamond patterns turning normally bland walls into
dynamic texture and shadow rich backdrops.
The bridge includes several
aesthetic LED lighting components throughout. Beneath and integral to the roof
of the cladding system, cove lighting will wash the interior ceiling/walls with
controllable color LED lights. This light will permeate the metal skin creating
an internal glow for the enclosure. The exterior of the bridge enclosure and
ramps are encircled with continuous controllable color LED strip lighting,
reinforcing movement along its serpentine form, as shown in the rendering. The unique lighting system for the
bridge creates a customizable experience during events. Hundreds of lighting
combinations are possible to celebrate any given occasion. The lighting
includes rope lighting outlining the ramps, interior lighting for the
architectural skin, and railing lighting.
The pedestrian bridge was designed
and constructed under a fast-paced design-build delivery method. This project
was extremely challenging due to the coordination required with GDOT, MARTA,
City of Atlanta, Georgia World Congress Center, Home Depot Backyard
construction, and the general contractor – Georgia Bridge and Concrete. Since
the bridge sits directly on top of MARTA, Atlanta’s underground transit, a
lightweight geofoam fill material was used in the western ramp to reduce
loadings on the underground tunnel. Without this unique construction method,
permitting by MARTA would have likely been denied.
Additionally, the 17.5’
vertical clearance over Northside Drive required by GDOT, along with the
requirements for ADA compliance, demanded the serpentine design to fit on the
site. Without the curvature of the ramps, the project wouldn’t have met these
requirements. With a limited footprint allowed for the bridge design, several
layouts and alternative were considered before choosing the optimal layout.
Creating a natural flow of pedestrian movement for the bridge entrances was
important. The CPL team aligned the eastern ramp to point directly at the
Mercedes-Benz Stadium northwest gate entrance while reinforcing the ramp
entrances with a gateway created by opposing granite obelisks. The obelisks are
the base for aluminum vine sculptures representing the surrounding Vine City
community and the dynamic nature of the sporting events in the stadium.
Working
from a conceptual design prepared by Callison / RTKL (a design consultancy of
Arcadis) prior to the City’s RFP, CPL lead the effort to balance the initial concept with new technical and budgetary considerations. CPL served as lead
transportation engineer on Georgia Bridge & Concrete’s design build team.
The bridge was designed in accordance with AASHTO LRFD and Georgia Standard
Specifications. The bridge was completed in time to be utilized for the 2018 NCAA SEC Championship football game as well as Super Bowl LIII on Feb 3, 2019.
FOLLOW this link to watch a time-lapse of
its construction!
Key Contacts: Kevin McOmber, PE, Bradley Cox, PE or Scott Gordon, AIA, NCARB, LEED AP
