to and from Hatteras Island are noticing ever-increasing activity at
the site of two new bridges for Hatteras Island -- the Bonner Bridge
replacement over Oregon Inlet and the new temporary bridge at the site
of the inlet cut by Hurricane Irene in 2011.
Construction officially began on the new Bonner
Bridge on March 8 with a groundbreaking ceremony attended by the
governor and other dignitaries, and since then, three separate
construction sites that include huge barges have popped up on either
side of the Bonner Bridge, as well as in the middle of Oregon Inlet
“We have three work zones,” explains Pablo A.
Hernandez, the resident engineer for the North Carolina Department of
Transportation (NCDOT) and the project manager for both projects. “And
these three zones will [eventually] link up.”
Up until this point, the construction crews at
the Bonner Bridge have mainly focused on clearing the site and getting
ready for the literally big work to begin.
“We’re breaking out of the ground,” says Pablo. “…Just like building a property or a house, you need to clear the ground first.”
One of these initial projects, which visitors
crossing the bridge may have already noticed, was the installation of a
slight detour on the southern terminus of the bridge to minimize impact
on the Pea Island National Wildlife Refuge.
In addition, the three work sites were
established in this early phase, including the one that’s at the center
of the bridge. The construction crews utilize a crew boat that runs
from the south side to the work barges to access the
The next step in the process is installing the long line of pilings that will serve as the foundation of the bridge.
Visitors who are traveling along the northern
terminus of the Bonner Bridge may have already noticed the first trio
of pilings slowly sinking into the ground. These are the initial
pilings, and they are driven deep into the sandy bottom to provide
“Our goal is to get the pilings to minus 120
feet,” says Pablo. “That’s our goal, and we’ve been successful at
getting to that elevation.”
This means that if sea level is set at 0 feet,
the pilings will extend downward for 120 feet into the water from this
initial sea level mark. Pilings on the land will extend downward a
distance of 85 to 110 feet from sea level.
And while they’re being installed, the pilings
have to go through multiple layers and different varieties of sand, as
well as several layers of clay or other sediments.
It’s an intricate process that understandably requires a lot of prep work, including research and some trial and error.
The pilings are 54 inches in diameter and are
about 135 to 145 feet long. Once they’re soundly driven into the water,
however, only 4 to 5 feet of these initial structures will poke out of
the inlet. On top of these pilings, the construction crews will set a
hexagon shape footing and then a secondary column on top of that. Then,
the giant slabs of concrete will roll in to complete the newly finished
Bonner Bridge and officially connect the three stationed work sites.
The pilings portion of the process is expected to
take about 12 to 18 months, Hernandez said. The new Bonner Bridge is
slated to be completed by fall of 2018, and the “old” Bonner Bridge
will be torn down by fall 2019.
Anglers will be happy to learn, however, that not
all of the old bridge will be torn down. More than 1,000 feet of the
original “Bonner Bridge” on the southern end will remain to serve as
both a fishing platform and a structure to help control and maintain
the Davis Slough.
There are two channels that run through the inlet
– Oregon Inlet and the southern Davis Slough – and the U.S. Army Corps
of Engineers determined that the foundation of the old bridge helped
keep the Davis Slough open for mariners.
“By keeping it there, it will also stabilize the
inlet,” says Hernandez. As a result, this section of the “old” bridge
will remain open for pedestrians well after the project is over.
When it’s complete, the new bridge will be longer
than the existing bridge, and will extend for 2.8 miles. The full route
will be a total of 3.5 miles, including the new roadway leading up the
bridge. The new bridge will also have a lifespan of 100 years – far
more than the 30-year lifespan that the current Bonner Bridge has
In addition, the new bridge will have more
navigational leeway for mariners. With a total of seven navigational
spans, each measuring an average of 300 feet wide, there will be more
options for navigating under the bridge. The new design
also has 12-foot travel lanes and wider 8-foot shoulders to make it
safer for travelers. There are no shoulders on the current bridge.
PEA ISLAND INLET BRIDGE
The other big project that’s already well
underway is the new temporary bridge over Pea Island Inlet that will
replace the smaller so-called "Lego" bridge that has been in place
The new bridge will have a total of 57 spans that
each will be 50 feet long. So far, a total of nine spans have
been installed, and Hernandez estimates that the construction crew will
add the remaining spans at a rate of two every two or three weeks.
“We’re out of the breach, and there’s more room to work around,” he says.
It’s a rough job to be sure. Construction crew
members have had to slog through dry sand in hot summertime
temperatures to get the project started. However, with the first spans
installed, the construction is now moving at a smooth pace.
The Pea Island Inlet bridge will have pilings
that are 16 inches square, as opposed to the 54-inch diameter pilings
of the Bonner Bridge, which helps speed up the process as well.
Currently, there are two separate crews that are
working at multiple job sites at multiple times throughout a 24-hour
period. The day crews and night crews both log in roughly 8 to10 hours
of work a day, which overlaps in the mornings. This means that the
bridges are being worked on roughly 16 to 20 hours per day.
And as the ground preparation work ends and the
pilings start to be driven in, locals and visitors driving across the
Bonner Bridge can expect to see ample changes in the local landscape in
the months to come.
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