By Sam Walker on March 6, 2014
The N.C. Department of Transportation says it will begin to work on another area of sand scour that was identified in the vicinity of four sets of pilings supporting the Bonner Bridge in December.
While the highway department says the erosion around the bases of the pilings is not nearly as severe as similar scouring that led to the closing of the bridge for 12 days in December, crews will be placing sandbags near support bents 162 through 165 over the next three months.
Meanwhile, traffic will be stopped at each end of the bridge for about 30 minutes on Monday morning for a routine scan of the alignment of the entire span over Oregon Inlet.
The NCDOT installed scanning technology in 2012 to allow it to closely monitor any movement of the bridge, according to a news release.
A series of points are marked along 150 of the 200 span sections, with each point surveyed before the start of hurricane season and after each storm to see if it has moved.
Monday’s scan is scheduled for 9 a.m. and will be the first of several throughout the year, as well as after any severe storms. Good sunlight and minimum shadows are needed for the scan to be done properly. If it is cloudy or the weather is not favorable, the scan may be rescheduled.
Carolina Bridge Co. of Orangeburg, S.C. completed the emergency repair project last month at Bent 166 where critical levels of scour around the piles of the support structure required NCDOT to close the bridge on Dec. 3.
The bridge reopened to traffic on Dec. 15, 2013, following an aggressive dredging effort that pumped about 30,000 cubic yards of sand around the piles.
Carolina Bridged placed 78 3-foot by 3-foot sandbags, 158 4-foot by 4-foot sandbags and 980 individual A-Jacks bundled together into multiple logs around bent 166.
Now that the emergency repair work is done, the department has begun a similar project with Carolina Bridge from bent 162 to bent 165 after seeing the new area of scouring appear in December.
The estimated $1.8 million project includes placing 3-foot-square by 3-foot-tall sandbags around the pilings of each bent, and 5-foot-square by 5-foot-tall sandbags between each bent.