As a temporary measure workers wrapped two steel bands around the tops of the bridge piers, then applied tension. Courtesy of the ICC Project
Workers add reinforcements to three bridges along the new Intercounty Connector in Maryland while engineers develop a long-term fix for hairline cracks in the concrete piers.
November 1, 2011
Three new bridges crossing the recently opened Intercounty Connector (ICC) toll highway in the Maryland suburbs of Washington, D.C., are undergoing temporary repairs to reinforce concrete piers that have developed hairline cracks.
Cracks are visible in all 13 piers of the three bridges, on Georgia Avenue, Emory Lane, and Needwood Road. The cracks—as many as 50 in total—vary from .005 to .035 in. wide. The shortest is 7 in. long; the longest is 3 ft, 8 in. long, according to Ray Feldmann, the senior communications manager for the ICC project. Engineers have determined the piers have insufficient steel reinforcements based on an inaccurate model used by the bridge’s designer, Feldmann said.
Three new bridges crossing the Intercounty Connector (ICC)
toll highway in the Maryland suburbs of Washington, D.C.,
have developed hairline pier cracks. Courtesy of the
The concrete piers were designed by a joint venture of Parsons Transportation Group of Pasadena, California, and Jacobs Engineering of Pasadena, California, according to a Maryland State Highway Administration press release. A spokesperson for Parsons declined to comment, referring questions to ICC officials. Any costs involved in these modifications will be the responsibility of the contractor.
“During recent state inspections, hairline cracks were identified on several concrete piers of the three bridges,” said ICC project director Melinda Peters, P.E., M.ASCE, in a press release. “After consultations with the engineering and contracting teams, and an independent expert, it has been determined that modifications to supplement the support structures are required to ensure the long-term safety and durability of the bridges. The contractor has been directed to immediately begin making short-term modifications and develop the plan for further long-term corrective actions.”
Workers began short-term repairs on October 18 to strengthen the pier caps, Feldmann said in written responses to questions from Civil Engineering magazine online. The repair consists of wrapping two steel cables around the tops of the piers, then applying tension.
“The design/build team is working on concepts for a long-term solution now,” said Feldmann. The bridges will remain open during repairs, but the work will require lane closings on the ICC below.
The three bridges cross over the first leg of the ICC, which travels from west to east through the Maryland suburbs of Washington, D.C., about 8 miles north of the Capitol Beltway. This 7.2 mi section opened on February 23, 2011, linking I-270 in Gaithersburg to Georgia Avenue, near Norbeck. The second leg of the ICC, 10.7 miles between Georgia Avenue and I-95, is on schedule to open by the end of this year, according to the state department of transportation. A third leg will bring the final length of the road to 19.3 mi.
The ICC is the culmination of 61 years of studies and plans to link the Maryland suburbs outside the nation’s capital. Although a plan dating from the 1950s to create a beltway linking the outer suburbs of Maryland and Virginia beyond the existing beltway formed by interstates 495 and 95 was dropped in 1968, the idea of a highway that linked I-270 to U.S. Route 1 in Maryland remained on the drawing board, eventually becoming the ICC.
The project, which began in 2008, will eventually cost $2.56 billion. Videos of the project can be found here: http://www.iccproject.com/video-archives.php.