Page 4 - Elements-Spring2013
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“ We trust CEC continued from previous page
to position all those defi cient. Once Mayor Graves realized the project was more than $29.6 million to
critical things for us.” bridge project was fast-tracked, she seized replace the Cumberland River Bridge and

the opportunity to get in on the front end construct an additional backwater bridge.
- Josh Randall, Mountain States Contractors and initiated talks with TDOT, as well as Both were to be built over Old Hickory
Sumner and Wilson Counties, both of which Lake—a mainstream storage impoundment
would be aff ected. She felt strongly that the to the Old Hickory Lock and Dam built on
bridge should serve as a true gateway into the Cumberland River between 1952 and
the city and be impressive when traveling in 1954. The river backs up and spreads out
either direction. because of the dam, forming the lake.
Nashville-based Mountain States TDOT generously welcomed Gallatin and
Contractors was awarded the project as Wilson and Sumner Counties to collaborate
the prime contractor, with Britton Bridge as on the incorporation of amenities and
P and Civil & Environmental Consultants, without competition, to provide input S
the structural steel erection subcontractor,
aesthetic design of the bridge. The
partnership agreed on bicycle lanes and
Inc. (CEC) for construction staking,
pedestrian pathways over the bridge.
environmental and CQA services. Mountain
These connect to a trail that runs along
States looked to CEC because there are
only a few fi rms in the state that can do the the side of the abutment and curves
under the bridge to provide a view of the
challenging work for the planned bridge river. Having the counties come together,
project. “There’s a history of a good working
An eight-pier bridge that spans relationship,” said Josh Randall, Project for the Gateway Bridge helped TDOT to
challenging topography and a deep- Manager for Mountain States. “We have move forward on this important project.
water navigable channel is not the worked with CEC successfully on a number
product of your standard construction of jobs. Mountain States has a great deal of Construction began in April of 2011, and the
staking job. “To survey, we had to set confi dence in CEC’s work.” new bridge is slated to open to traffi c this
up points on either side of a wide river fall. The entire project will be completed in
with banks at diff erent elevations, and It wasn’t your standard bridge-building the spring of 2014 when the old green truss
even then, not everything was perfectly project. In fact, nothing like it has been bridge will be relieved of its post. ■
visible,” said John Gravely, CEC Principal. built in the area before. The bid cost of the
But for CEC, determining the position of
structural components for the new 109
Gateway Bridge into Gallatin was a goal
within sight.

Working primarily on a barge, CEC lined Coff erdams allowed the surveyors to
up seven coff erdams—steel enclosures continue lining up their equipment with an
that are sealed off and pumped dry for instrument positioned on land or on one
construction below the water. The dams of the newly-constructed piers.
protect the forms into which concrete
is poured for the footings and columns
of each pier. But the fi rst step was to
determine the design location of the
piers in moving water of varying depths.
The fi rst six piers would stand in shallow
water, but the gradually-sloping river
bottom suddenly makes a steep drop
nearly 70 feet, creating a logical location
for barge traffi c. The seventh pier would
need to be positioned in that deep water
to properly support a 385-foot span over
the channel to the last pier, which would
sit on top of a vertical river bank.

“The atypical details on this project
took time from an engineering and
survey perspective,” said Josh Randall
of Mountain States Contractors. “CEC
determined where to put the coff erdams
down in the river and where to build the
foundation that the public will drive on. ■
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