The Virginia Department of Transportation awarded a $42-million contract to Branch Highways Inc., based in Roanoke, VA, for the new Route 460 interchange with I-81 in Christiansburg, VA. The new interchange, which has been under construction since spring 1998, is about 61 percent complete. After several million dollars in upgrades, the project is now estimated to cost $49 million.
The project, which involves 5.4 kilometers (3.3 mi.) of I-81 and 1.8 kilometers (1.1 mi.) of Route 460, will extend Route 460 from Roanoke Street to a new interchange at I-81. The contract includes the widening of I-81 to six lanes, construction of collector-distributor roads parallel to the interstate, and building a new interchange. The building of ten new bridges and the replacement of two existing bridges also are incorporated into the project. The collector-distributor lanes should be completed in June 2000, and traffic will be shifted to these new lanes while work on improving and widening existing I-81 begins.
The major subcontractors on the project are Adams Construction Corporation of Roanoke, Blount-Sanford Construction Co. of Atlanta, and Century Concrete of Virginia Beach. Adams Construction will be performing all of the paving for the interchange project. Century Concrete will be erecting $4 million worth of sound wall, which will be one of the first sound walls to be used in VDOT’s Salem District.
Blount-Sanford will be installing 4 kilometers (2.5 mi.) of median barrier walls and 300,000 centimeters (10,000 ft.) of outside barrier walls. Innovative forming techniques and a Gomaco Commander 3 slip form machine will be used in the barrier wall construction. In addition, approximately one mile of the project has a special wall incorporated in the design.
Blount-Sanford owns six slip form machines and has two slip form crews covering nine states. On the Christiansburg project, the company employs a superintendent, a general superintendent and 13 to 16 people on the crew. Construction of the barrier walls is a continuous process. Concrete is poured into the form of the machine and vibrators extrude the concrete out of the molds from the rear. After the barrier is formed, finishers look for any problems and put the specified finishes on the concrete. “It’s really specialized work,” said Ed Raynor, vice president of Blount-Sanford.
By the time the new interchange is complete, Branch highways and its subcontractors will have moved 1.2 cubic meters (1.5 cu. yds.) of excavation, erected 21.4 kilometers (13.4 mi.) of piling, and laid 248,395 metric tons (273,235 tons) of asphalt. The company will also have handled 13.9 kilometers (8.7 mi.) of concrete pipe and 43.4 kilometers (27.1 mi.) of underdrain.
The new interchange was needed to accommodate increased traffic in the Christiansburg and Blacksburg areas. Nearby Virginia Polytechnic Institute and State University, better known as Virginia Tech, is one of many draws to the Blacksburg area. The new interchange also will aid drivers in reaching Smart Road facilities. In the future, VDOT plans to improve I-81 in other parts of the state.
Pete Kramer, project manager at Branch Highways, said, “There have been $5- to $6-million of upgrades in the design of this job, so that it will coincide with future upgrades of I-81 from Wytheville to Staunton.”
The Route 460/I-81 interchange is scheduled for completion in summer 2001.