S.C. Department of Transportation officials are planning for a year of construction projects to improve the longevity and safety of the Wando River bridge on Interstate 526 — a critical Lowcountry motorway that closed last spring after a primary support cable snapped.
DOT Deputy Secretary for Engineering Leland Colvin and other DOT officials spoke about the agency's progress and outlined the next steps at a press conference Friday in North Charleston. A 2,800 page final report on the bridge was released with recommendations on repairs and monitoring systems.
"The bridge is safe," Colvin said. "We're going to continue our (daily) inspection walk-throughs until we implement all 14 recommendations as noted in the report."
DOT has identified nine recommendations as high priority, Colvin said. On March 12, the agency will receive bids for a construction contract on those nine recommendations. He didn't specify when construction would begin but said work was anticipated to be completed by spring 2020.
The James B. Edwards Bridge, as it is formally known, has had allegations of shoddy workmanship and design defects dogging it from the beginning. The span ended up opening two years behind schedule in 1991.
Only four years after it opened, its innovative aluminum expansion joints began failing, damaging cars passing over the bridge. The joints were replaced. But inspections over the years repeatedly noted problems with the bridge’s joints, along with cracks, chipping and other issues.
Last May its cable support system was the source of the problem when a primary cable snapped. National experts later determined the culprit was corrosion from water seeping through the bridge’s concrete deck.
Secretary of Transportation Christy Hall was at the press conference Friday but declined comment. When the bridge reopened in June 2018, Hall expressed confidence in the troubled bridge.
"Just to reassure everybody, I have no concerns whatsoever about this bridge and we will do the maintenance necessary to make sure we get years of life to come out of this structure," Hall said. The anticipated lifespan of the bridge is 75 years.
In order to complete the new construction, officials anticipate some nighttime closures as well as traffic shifts during two weekends in the fall of this year, Colvin said. No dates have been set for those anticipated closures.
The weekend traffic shifts would begin after a Friday rush hour and end before rush hour the following Monday, Colvin said. One lane on each span of the bridge would remain open while the shifts are in place.
An estimated 35,000 motorists cross the bridge on an average day.
The impact of weekend and nighttime closures for construction will likely be far less than what was seen during the emergency closure last year when drivers reported up to two hours being added to their commutes.
Charleston Mayor John Tecklenburg was in Washington D.C., on Friday and was unavailable for comment. A Mount Pleasant town spokesperson could not be reached for comment.
DOT Commission Chairman Robby Robbins said he is confident in the repair and retrofitting plan.
"The bridge is safe," Robbins said. "That was our main priority back in May of last year and it continues to be our main priority."
The DOT has spent about $6 million on repairs so far. Officials on Friday didn't have an estimate for the cost of work going forward.
Colvin broke down the nine main recommendations in the report during the press conference.
Over the next 15 months, crews will replace two additional cables on the westbound span of the bridge, the same span where a cable failed last year, he said. The eastbound span hasn't had any cable failures, but crews are slated to install two redundancy cables, bringing the total number in both main spans up to 10.
Each cable is made up of 19 wires with seven strands of steel per wire, Colvin said.
The report also identifies repairs needed on sections of the bridge that approach the main span, he said. Crews will replace one minor cable on the westbound approach span and two minor cables on the eastbound side.
Officials plan to repair and improve portions of the bridge deck in order to prevent water intrusion and damage.
Crews have completed work to repair and seal joints on the westbound span's deck, Colvin said. They plan to repair joints as needed on the eastbound side before sealing them.
There are 52 joints on each span, he said.
Plastic conduits that protect cables and the points where they are anchored to the bridge structure will also be sealed to prevent water damage, Colvin said.
Once that work is completed, officials will move on to the remaining recommendations in the report, such as installing a more sensitive acoustic monitoring system, he said.
Crews have already installed some monitoring technology on both the east and westbound spans, Colvin said. Microphones are used to detect sounds produced by breaks in the steel strands that make up the cables. Structural engineers receive text message alerts if a cable snaps.
The new system will be able to alert DOT officials if one strand within a cable breaks, he said.
Inspectors are also continuing daily walk-through inspections of the bridge’s cavernous interior.