The Lowcountry was caught off guard when a cable rupture shut down the Wando River bridge last month. But state officials knew for the better part of a decade that leaky joints and corrosion posed a double-edged threat to the span’s integrity.
The James B. Edwards Bridge, which opened to traffic in 1990, has been plagued with problems almost since its inception. And inspection reports released Thursday showed engineers had raised alarms about water intrusion and rust as far as back as 2010.
Some of the issues appear to date back to the span’s construction, including poorly sealed joints that let water seep down into the network of support cables and eat away at their casings and steel. What’s more, engineers repeatedly noted that duct work covering the cables made it nearly impossible for them to see how the cables were faring in this corrosive environment.
"It's clear to me from looking at the documents ... that these bridges have been problematic almost from the beginning, especially in regards to water intrusion," Department of Transportation Secretary Christy Hall said. "This appears to be a very common issue with these types of bridges."
The $32.1 million Edwards bridge is a box-girder concrete construction that uses "tendons" to support some of the weight of the concrete itself. The design’s efficiency and affordability has contributed to its popularity around the nation, but corrosion has been a persistent issue.
The thousands of pages of inspection records, emails and photographs posted Thursday on the DOT's website showed how troublesome the span has been. The Post and Courier had requested the documents through the South Carolina Freedom of Information Act.
Parsons Brinckerhoff, a global engineering firm, inspected the Edwards bridge in May 2010 and noted that several cables showed signs of water intrusion, indicated by the salt build-up along their casings. Some of the drainage holes inside the box girder were placed in inappropriate locations, they noted, causing water from the expansion joints to pond.
The experts recommended a more intensive study because ductwork blocked their ability to inspect the cables more closely.
The engineers noted several other problems as well, including signs of grout leakage during construction, inadequate corrosion protection of cable anchor bars, “use of duct tape for connections,” incorrect drain locations and leaky joint segments.
State Rep. Nancy Mace, R-Daniel Island, has been pushing for answers about DOT’s monitoring of the bridge since the shutdown occurred. She said Thursday’s revelations suggest steps could have been taken to head off problems before they resulted in chaos and gridlock.
“On the surface, this seems like it was possibly a preventable situation,” she said. “Based on what I know today, this situation we are in as a town should not have happened. The situation is unacceptable.”
'Serious' issues found
Allegations of shoddy workmanship and design defects had dogged the bridge from the beginning, and the span ended up opening two years behind schedule.
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. But its cable support system would eventually pose the biggest threat.
In 2011, Parsons Brinckerhoff returned to join two other firms and conduct an in-depth study of the span's cables.
The cables consist of steel wires encased in concrete and covered with a protective sheath meant to seal them from moisture. But the inquiry found large air pockets in many cables, allowing enough oxygen for corrosion that would accelerate "significantly" with exposure to water. Some of the concrete inside the cables was crumbling.
"Serious durability issues were discovered," the report stated.
The experts suggested repairing the problem spots in the cables "as soon as possible" and sealing holes in the bridge deck to halt rainwater.
DOT Deputy Secretary of Engineering Leland Colvin said Thursday that the state quickly followed through on those recommendations.
But problems persisted.
Subsequent inspections in 2012, 2014 and 2016 gave the span’s box girder system a satisfactory rating. But engineers noted that they were unable to examine the cable tendons due to the duct covering, making it impossible to say for sure what was going on underneath. They referred back to the 2011 study.
Still, red flags were evident. Engineers walking through the belly of the span in 2014 noticed water flowing from the roadway, salt deposits building up and corrosion eating into the metal parts that keep the bridge’s cables in place. At the top of the bridge, they saw pools of water an inch deep. Two years later, they were still there.
Lee Floyd, a state engineer specializing in bridge maintenance, raised alarms about the span as well. In 2016, for instance, he wrote to his boss that he wanted to sit down to “discuss my concerns about the serviceability of the I-526 bridges.” Earlier that year, a cable in the bridge structure had been damaged.
Contractors fretted that they didn’t want to block traffic during Thanksgiving to fix it. Floyd snapped back in an email: “I think we need to make a decision here as to what is really more important.”
“Is it restoring the structural integrity of the bridge or just pure convenience to the motoring public?” Floyd wrote. The bridge was holding, he said, but he told management that “we needed to proceed ASAP.”
Around the same time, another report found more issues, largely faulting how the cables were assembled. The high water content in the concrete caused cracks. The sulfate percentage was more than five times the accepted level, preventing a protective film from forming around the steel wires in the cables.
Hall said experts had taken several measures to stop water from entering the structure and hitting the cables over the years. To date, she said, the state had spent millions to investigate issues and fix them, even before the latest round of repairs.
But corrosion continued, leading last month to the cable snapping.
Hall said the state will do what it takes to keep the bridge in service, including resurfacing the span to keep water from seeping through the joints.
Mace, the state lawmaker whose district includes the bridge, said she will keep pushing for answers. Among other things, she wants to know when, if ever, the bridge surface was last resealed to prevent water intrusion. The answers to such questions may help prevent a similar situation from occurring again, she said.
“The biggest thing going forward is making sure these issues are fixed,” she said. “I want to make sure something like this doesn’t ever happen again.”
Thad Moore and Gregory Yee contributed to this article.