By Sam Walker on November 15, 2012The N.C. Department of Transportation said Thursday the first visible signs of preparations to replace the Herbert C. Bonner Bridge over Oregon Inlet will begin in the coming weeks.
Despite lawsuits filed by environmental groups to further delay replacement of the 50-year-old span, construction is slated to start in early 2013.
NCDOT is moving forward with the Bonner Bridge Replacement Project, with 75 percent of the design complete, according to a news release.
Two barges loaded with materials and equipment are scheduled to start arriving from Chesapeake on Friday at Oregon Inlet, weather permitting, according to the statement.
Crews will be driving test piles, large columns positioned in the earth to support a bridge. The tests are necessary before construction can begin to verify engineering estimates of how much weight the piles can safely bear.
The process will ensure that the bridge’s design is sound and buildable, according to the statement.Crews will begin constructing a temporary positioning device that will hold the piles in place during testing, which will take about two weeks.
The piles will go 110 feet deep into the earth, making them some of the deepest jetted piles along the East Coast.
Some of the test piles will be placed into the ground in the footprint of the new bridge, which is just west of the current span.
After perfecting the pile installation process, the contractor will start in early January testing how much weight the piles can handle.
Three hydraulic jacks will use force to measure each pile’s ability to support weight, ranging from 3 million pounds to 3.6 million pounds. The average bridge pile supports about 500,000 pounds.
The pile testing is scheduled to be complete by mid-January.
At that time, crews will remove the piles and the positioning device, and ship them by barge back to Virginia.
The above video was created by HDR Engineering Inc., the design firm working with PCL Civil Constructors Inc. on the bridge replacement project.
Among the features of the new bridge will be more numerous and wider navigation spans, which will allow better options for boaters as the channel through the inlet shifts around.
The former bridge will be torn down, except a short section on the south side that will become a fishing pier.
A proposal for the remains of the rest of the current bridge is to place it in portions of the Pamlico Sound and adjacent waters to create finfish and shellfish habitats.
Environmental groups continue to lobby for a 17-mile long bridge that would stretch from the tip of Bodie Island to Rodanthe village, bypassing all of Pea Island.
The NCDOT says that option is not cost effective, and instead plans to build the new Bonner Bridge as a parallel span, and address issues along N.C. 12 between the inlet and Rodanthe on a case-by-case basis.
“The work will in no way impact the NCDOT’s dedicated effort to repair, reconstruct and reopen N.C. 12 to traffic in areas damaged by Hurricane Sandy and the (early-November) nor’easter,” read the statement.
During testing, the barges will not block the navigational channel in Oregon Inlet.
NCDOT advises mariners to avoid the areas where the barges are located to ensure safety. They will be marked in accordance with U.S. Coast Guard guidelines.