Engineers for Maryland's most high-tech highway are nearly half way to mending hairline fractures found in 10 of the bridges that carry the Intercounty Connector between Gaithersburg and Laurel.
Repair work has wrapped up on four of those bridges and is set to start this week on three more. But who’s to blame for cracks at two other bridges remains at question. The contractor who designed those bridges is disputing the state’s assessment that the cracks are the contractor's fault.
The ICC’s western third opened in February 2011 amid a flurry of both fanfare and skepticism.
Eight months later, inspectors found cracks in three bridges along that 7.2-mile stretch—known as “Contract A”—in the ICC’s “pier caps,” the concrete structures between a bridge’s vertical support columns and the roadway itself.
Steel rods inside the pier caps help give the structure strength. Designers had miscalculated how many steel rods were needed inside the pier caps to properly support them, state officials told The Washington Post.
The ICC’s next 10 miles—“Contract B” and “Contract C”—opened in November, stretching to Interstate 95 in Laurel.
After discovering the first three cracks, engineers pored over each of the $2.56 billion toll-road’s 49 bridges and overpasses and found seven more fissures in the 17 miles that have so far opened.
The 10 affected bridges are:
Contract A: Georgia Avenue, Emory Lane, Muncaster Mill Road, Needwood Road and Redland Road.
Contract B: Longmeade Crossing Drive, Notley Road and Layhill Road.
Contract C: Route 29 and the ramp that takes Route 29 traffic westbound onto the ICC
Each instance stems from the same design flaw, said Dave Buck, spokesman for the Maryland State Highway Administration. While the problem would affect the bridges' long-term structural integrity it has not compromised drivers' safety, he said.
The cracking has been “nothing that was imminently a [safety] concern in any way, shape or form,” Buck said.
Fixing the pier caps involves inserting more steel rods, which should strengthen the structures up to “what we expect this to handle for the next 60 to 80 years,” Buck said.
So far, the repairs have come at no expense to taxpayers. The builders of Contract A and Contract B took immediate responsibility and paid for the repairs, Buck said.
Repairs to four of the five bridges in Contract A are complete, with the work on the Redland Road bridge expected to finish within a month, Buck said.
Repairs to the three cracks in Contract B will begin Thursday, Buck said.
Traffic should be minimally affected, he said.
Cracks to a pair of bridges where the ICC links up with Route 29 garnered attention last week, but that damage was found months ago as part of the ICC-wide inspection, Buck said.
Fixing those two bridges—part of the 3.8-mile “Contract C” that opened in November—is headed for a standstill. Contract C’s design firm—the Fairfax, VA-based engineering and architecture firm Dewberry—disputes the state's claim that the cracks arose because of the same design flaw blamed in the other bridges.
Dewberry has commissioned a third-party review.
"This is in process. We're cooperating with the state, responding to their minor questions about ICC Contract C, which have largely been resolved. We expect the final review to confirm the design is sound," said Molly Wagner, a Dewberry spokeswoman.