Demolition of the U.S. 25 bridge crossing I-26 near Fletcher, NC, began last month.
The 40-year-old, 69 ft. (21 m) wide, five-lane bridge will be replaced with a new 93 ft. (28.3m), 7 in. (17.7 cm) bridge with two through lanes and a turning lane in each direction. There also will be 5.5 ft. (1.68 m) wide sidewalks on each side and wider than normal shoulders for emergency pull-off or future expansion.
Business growth and increased traffic at the U.S. 25/I-26 interchange, along with the old bridge vibrating when heavy tractor trailers crossed it or traffic stopped on it, initiated the need to replace the bridge.
The bridge project is estimated to take three years and is part of a $22.2 million project to widen 3.9 mi. (6.3 km) of U.S. 25 from the new bridge south to Brookside Camp Road.
Taylor & Murphy Construction, Asheville, NC, is the subcontractor for the bridge demolition, removal and construction. John Herrin is the project manager.
According to Herrin, rather than demolishing the entire bridge at one time, the company implemented a removal-controlled operation, where portions of the bridge are systematically removed and cleaned up.
“The biggest challenge to this project will be removing and constructing the bridge around the public in a safe matter –– all while working on top of an interstate. [It’s] like working over a NASCAR track with anything but cheering crowds,” Herrin said. “It is a very dangerous job and we must make sure no unknowns happen in the process.
“The removal-controlled operation of bridge demolition will also allow us to reduce the impact on traffic,” Herrin explained. “Minimizing the impact on traffic was crucial in the planning of this project and, in fact, a restriction in the NCDOT contract specified that any work being done that might impact traffic on either U.S. 25 or I-26 must be done at night, between 9 p.m. and 6 a.m., which meant that the majority of the work was done at night when temperatures were well below freezing.”
According to Roger Hamilton, NCDOT transportation technician, just prior to the night time demolition, traffic passing along I-26 was re-routed up the off ramps and down ramps at the intersection of U.S. 25.
“The first step in the demolition involved sawing the joint down the center of the existing bridge and removing the two northbound lanes,” Hamilton said. “On the first night, the deck on the eastbound I-26 side of the bridge was crushed. The second night the steel girders were removed. On the third night the deck of the westbound I-26 side was crushed and, on the forth night, that side’s steel girders were removed. A fifth night was required to tear down the substructure of the bridge.
“Due to weather problems, it took a total of two weeks to complete the demolition of the one half of the bridge,” Hamilton said. “The three remaining previously southbound lanes of the bridge will be open during the day to traffic. When the northbound lanes construction is complete, the southbound lanes will be removed and reconstructed.”
A Volvo EC 290 hydraulic excavator mounted on a BTI MP40 processor was rented from L.B. Smith for demolition of the bridge.
LB Smith, located in Arden, NC, is a distributor of Volvo Construction Equipment North America, of Asheville, NC. According to Steve Brown, sales representative of LB Smith, this processor weighs 77,000 lbs. and has the ability to use three different jaws.
“The cracking jaws were used to saw the roadway from the deck, cutting away the concrete, the shear jaws were used to cut the rebar steel, and the pulverizer jaw was used to pulverize the concrete and recycle it,” Brown said.
According to Herrin, an estimated 500 cu. yds. (382 cu m) of bridge will be removed from the bridge deck and substructure upon completion.
“The debris will be salvaged out,” Herrin said, “and the remaining concrete will be utilized in a fill operation.”
“Overall, the first half of the demolition of the U.S. 25 bridge went smoothly.” Hamilton said. “Our biggest concern was the traffic, but with the cooperation of the local police for traffic control all went smoothly.”