Preliminary scans of Bonner Bridge analyzed, additional tests scheduled for Sunday

Engineers have evaluated the data from sonar scans taken Wednesday at the bridge, as well as the results of the first pile-driving test conducted Wednesday. They have scheduled another sonar scan for Sunday, weather permitting, to look for any changes.

“The preliminary scans look positive. However, out of an abundance of caution, we want to do another scan to make sure the sand continues to stay in place before we make a decision on reopening the bridge,” said NCDOT Division 1 Engineer Jerry Jennings.

Crews today also drove a second test pile into the floor of the Oregon Inlet after high winds forced them to postpone it Thursday. This test helps engineers learn how much weight the existing Bonner Bridge piles can hold and the composition of the sand in the area where the erosion occurred.

NCDOT will use the results of the pile tests in conjunction with the sonar scans to assess the bridge’s ability to safely handle traffic.

These tests follow an aggressive effort last weekend during which crews pumped approximately 30,000 cubic yards of sand from the main navigation channel of the Oregon Inlet to the location at Bent 166 underneath the Bonner Bridge where scour, or the erosion of sand from bridge pilings, caused NCDOT to close the bridge on Tuesday, Dec. 3.

Emergency Repairs
Early next week, weather permitting, contractor crews are scheduled to begin installing the four-foot tall by four-foot wide sandbags and four-foot tall A-Jacks that will provide support to the bridge pilings and prevent further scour from occurring. Crews currently are in the process of mobilizing and preparing the equipment and materials needed for the repair work, including filling sandbags and assembling A-Jacks.

The A-Jacks will interlock and be placed around the perimeter of the support structure at Bent 166. Crews will then place the sandbags inside the line of A-Jacks. This will stabilize the sand that has been pumped around the piles as well as allow additional sand to collect over the sandbags and A-Jacks, providing additional support to the structure.

NCDOT awarded a $1.6 million contract to Carolina Bridge Company Inc. of Orangeburg, S.C. for emergency repairs on the Bonner Bridge.

Emergency Ferry Route
NCDOT’s Ferry Division activated its emergency route between Stumpy Point and Rodanthe with limited service the night of the bridge closure. The route went into full operation Wednesday, Dec. 4, with steady traffic and short-to-moderate wait times reported at both terminals. Dare County Emergency Management has issued a priority loading list for the route. The emergency ferry route will continue seven days a week as long as service is needed. Ferry information is available on the Ferry Division website, by calling 800-293-3779, or via Facebook and Twitter at @NCDOT_Ferry.

For More Information
NCDOT will continue to update the public on this situation online and via its N.C. 12 Facebook page and N.C. 12 Twitter account. Photos of the various activities conducted at the bridge can be found on NCDOT’s Flickr site.

Permanent Replacement
While NCDOT is working hard to reopen the Bonner Bridge to traffic as quickly as possible, the emergency repairs are not considered a permanent fix for the aging bridge. After 50 years of weathering many storms, the bridge needs to be replaced. In July 2011, NCDOT awarded a $215.8 million contract for the design and construction of a new bridge. Design work began immediately and construction of the new bridge was set to begin in early 2013; however, lawsuits have put the project on hold.

Read more about the history of the Bonner Bridge and the challenges to replacing this lifeline.