Wilcox Bridge Inspections and Repair Recommendations
The Wilcox Bridge was built in 1922 and is 97 years old. The bridge parallels US29/70, north of Spencer, North Carolina. It’s a historical 1300’ open spandrelreinforced concrete deck arch bridge spanning the Yadkin River. It has 4 spansof 43’ to 46’, and 7 spans of 160’ each. The bridge previously carried highwaytraffic and underwent routine inspections and underwater inspections every 24months and 48 months, respectively, by NCDOT, until its closure as a highwaybridge approximately 10 years ago. Davidson County commissioners tookover the ownership of the bridge and the bridge became part of the DavidsonCounty greenway system.
The last routine and in-depth bridge inspection was completed in 2010 and thelast underwater inspection was completed in 2012, both performed by NCDOT.Neither of these inspections were performed using the current FHWA elementlevel inspection standards. WEI met with former NCDOT inspectors andcontractors to track down the history of defects found and repairs made to thebridge in 2010. After these meetings, WEI was able to sit down with Countystaff and provide them with plans and information on how prior repairs werehandled. From there, WEI and the County made a decision on how to moveforward with the new inspection process.
WEI began the inspection in mid-November 2019. The scope of work includedroutine element level inspection, underwater inspections, repair recommendations, andpreliminary construction costestimates. During field inspection, two WEI inspection teams inspected the deck, girders, andsubstructures. WEIasked the County to close the bridge to all pedestrian traffic so that our teams could workfreely along the top sideand access the bottom side in an Aerial Aspen snooper truck.
One of the County’s biggest concerns was whether past hurricanes had created any scouring issues around the base of the footings. An underwater diving subconsultant was hired to investigate the three main bents and footings in the Yadkin River, and WEI took County officials out in a safety boat to observe during the underwater inspection process.
At the conclusion of the element level inspection field work, WEI engineers documented the size, location, severity and estimated repair cost of over 660 individual defects. By examining and prioritizing each defect found, WEI was able to provide the County with several cost estimates for immediate and long-term repair options. Additionally, the County was interested in applying an aesthetic coating to the bridge, and WEI was able to provide a detailed cost estimate for various options there as well.
Although this bridge’s underwater elements, length, age, and unusual configuration made for a challenging assignment, WEI engineers were able to complete it in a timely manner. From the first day of inspection, WEI engineers were able to present their draft report, including repair quantities and cost estimates, only 35 days later.