“It’s not as bad as it looks,” Lee Estes says as he points to an all-too-noticeable crack in the concrete.
Estes, a senior geotech with the South Carolina Department of Transportation, is inspecting the Highway 9 bridge over the Catawba River outside the tiny town of Fort Lawn. The 82-year-old structure along the Chester-Lancaster County line is a primary route for most traffic headed east from Interstate 77 in the area.
In this case, he was examining one of the concrete piers that support the bridge. “It looks bad, but that is a massive amount of concrete,” he says, “That is really thick and really strong.”
The SC-9 bridge is one of over 1,600 state-owned bridges that are classified as “substandard,” under federal guidelines. According to SCDOT, 890 are “structurally deficient,” meaning the structure is considered to be in “poor” (but safe) condition. An additional 777 bridges are considered “functionally obsolete,” meaning they do are too narrow or too low by modern design standards.
It would cost an estimated $2.9 billion for South Carolina to repair and replace all of these substandard bridges over the next 20 years. That is a hefty sum, when you consider that the state’s entire construction budget for fiscal year 2011-2012 was only $682 million. Of that only $139.7 million is set aside to repair or replace bridges.
State Bridge Maintenance Engineer Lee Floyd says the problem is that most of these bridges were built in either the 1930s or 1950s. And they’re now reaching the end of their life expectancy. “Those (1930s) bridges that are still in service are theoretically coming to the end of their functional life. Those (from the 50s) are either coming to the end of their functional life or either passing through a bridge ‘mid-life crisis,’ if you will.”
That is very clear on the ground. Todd McNinch is the Team Leader for bridge inspection in SCDOT’s District Four, which covers the Catawba River region in Cherokee, Chester, Fairfield, Lancaster, and York counties. He leads a pair of two-man crews that are required to inspect all 1,450 bridges in the region on a two-year cycle.
He says his district is struggling to keep the number of deficient bridges from increasing each year. “It was getting better, but now it’s holding steady with the money crisis the way it is,” he said, “We’ll get one down off the list… but then another one will come on. It’s a never-ending cycle.”
A big problem is funding. South Carolina’s primary method of highway funding is through gas taxes, which have not adjusted for inflation since 1987 and remain at 16 cents per gallon. Cars are also becoming more efficient, so the amount of tax money per mile traveled has gone down in that time.
SCDOT has long been trying to replace the Highway 9 bridge, which was built in 1930 and widened to two lanes in 1957. The estimated cost to do that is roughly $15-$20 million. However, a new transportation funding measure passed by Congress this summer would allow the state to build the bridge, McNinch said.
However, he worries the state is neglecting needed repairs as it prepares to tear the structure down entirely.
During a typical inspection, crews will start by looking at the top of the bridge, along the road itself. They note any visible cracks and do what’s known as a “chain drag.” That consists of the inspector pulling a chain behind him as he walks along the bridge, listening for a hollow sound that indicates an air pocket inside the concrete. Air pockets mean that the concrete has become separated from the supporting rebar, and is a likely sign that cracks and “potholes” will soon appear.
McNinch said that, for bridges over water, inspectors are also concerned about “scouring,” which is erosion in the riverbed that can cause a bridge to “settle” over time. Settling can lead to too much pressure on the wrong sections of the bridge’s supports. That can cause the concrete to crack. To check for settling, crews will dangle a measuring line over the edge of the structure to see if the sediment underneath has shifted since the last inspection.
The attention then moves to underneath the bridge. McNinch said his crew is only able to inspect a large bridge whenever it can get one of the state’s three “bucket trucks.” Since one of the trucks is currently being repaired and no one on his staff is trained to use another, that leaves a small window of opportunity. In fact, the crew has to drive this bucket truck to Laurens County once they finish so another crew in Greenville County can use it.
For this particular inspection, Estes was lowered in the bucket down to check the underside of Highway 9. He is a proud second-generation SCDOT employee. “My Daddy, the first job he had was working on this bridge when it was expanded,” Estes said as he looked for any new cracks in the concrete or rust in the steel.
He marks any new signs of trouble on his report. However, there are only a few on this day. The bridge had been inspected six months ago and there had not been any major storms since that would have caused scouring. There are very apparent cracks in the concrete and some chunks of the material missing, but those have been there for years, Estes said.
“This one is about ready for replacement, but it can still carry traffic with no weight limits,” he says as he finishes his inspection.
McNinch agreed. “You shouldn’t panic over what you’ve seen here,” he says as the crew begins putting up their equipment, preparing for their next stop nearly an hour away. “It’s not going to fall… But the main part of that bridge is 82 years old. So that’s 82 years’ worth of wear and tear on that bridge… But it’s something to be concerned about over the long haul. We need more funding to replace stuff like this.”