In April 2001, the Virginia Department of Transportation (VDOT) began work to replace the 52-year-old Southwest Virginia Memorial Bridge over the New River and the Norfolk Southern Railroad tracks.
The bridge, which is located on Route 11 and links Radford and Fairlawn in Pulaski County, is a single structure with two lanes for northbound traffic and two lanes for southbound traffic. When completed in fall 2004, the new bridge will have two structures, each with three lanes, and both spans will have sidewalks and bike lanes.
Replacing the Southwest Virginia Memorial Bridge first involves constructing a new southbound bridge, then demolishing the existing bridge and, finally, building a new northbound bridge.
The engineering/architectural firm Hayes, Seay, Mattern & Mattern, of Roanoke, VA, designed the new bridge, and Fairfield Skanska, of Fishersville, VA, is the contractor building the bridge.
Construction of the new southbound bridge, downstream from the existing bridge, was completed in August 2002, three weeks ahead of schedule. Once demolition of the existing bridge is completed and a retaining wall built on the Radford side, construction on the new northbound structure will begin, which is expected in late 2002.
To demolish the old Memorial Bridge, Fairfield Skanska hired a subcontractor, Demtech from Blue Springs, MO, to detonate explosive charges. A causeway for sections of the old bridge to fall onto has been built midway across the New River. Once the charges are detonated, two of the main truss sections spanning the river will drop onto the causeway, and the sections over the piers will fall to the side of the piers. The bridge will be brought down in segments with blasting to start on the Pulaski County side.
Fairfield Skanska has used a Kenco Slab Crab on a Hitachi EX330 to remove concrete slabs by sawing the existing deck into slabs and removing them with the Slab Crab bucket.
After the concrete is saw-cut into pieces, the Slab Crab’s teeth are slid under an individual piece. The piece is lifted slightly to break the remaining bond, then tipped back to a secure position and loaded — all with minimum impact to the subbase. The bridge deck was 1,500 ft. (457.2 m) long and was cut into 650 slabs. According to Skanska, it was able to cut its production time in half by using the Slab Crab bucket.
Slab Crab buckets range in size from 24 to 60 in. (61 to 152.4 cm). All Slab Crab excavator buckets are available as direct pin-on or with our Universal Connector. The Slab Crab is designed and constructed using high yield, abrasive resistant alloy steels for durability. The Slab Crab can process slabs ranging from 4 to 20 in. (10.2 to 50.8 cm) thick and is available for 20,000- to 150,000-lb. (9,072 to 68,039 kg) excavators, as well as loaders and skid steer machines.
