The new bridge across Patterson Avenue on the east side of Winston-Salem, NC, is taking shape right alongside the deteriorating bridge it will replace.
That’s the problem: The close proximity of one bridge to the other has handicapped the contractor on the project.
“It’s very difficult,” said David Rowe, president of Smith-Rowe Inc. “We’ve had to put this big steel together without having enough room to do it.”
The bridge will carry traffic on Oak Summit Road, which at that point rides the summit of a hill as it passes over Patterson Road. The existing Oak Summit bridge is a two-lane concrete structure that is showing its age.
Its concrete is pitted and, in some places, crumbling away. Cracks, apparently resulting from structural weaknesses, cut diagonally across the roadway surface and potholes have begun to appear. A new structure obviously is needed. So that traffic can be transferred without delay, the new bridge is going up in two phases.
Traffic initially will be routed across a completed first phase of the new bridge so the old bridge can be demolished. Then the rest of the new structure will be added and the final path of the roadway will be fixed.
Last summer, just one bridge spanned Patterson, and crews of Davie Grading, a Mocksville, NC, subcontractor, cleared and filled along the north side of Summit for the approach to the new span. Characteristic red soil of the Piedmont region of the state was hauled in and compacted by Davie under the steel drum and rubber tires of a Vibromax 1103 roller secured from United Rentals.
Where the earth spilled over the edge to Patterson, Davie crews carved away the embankment next to the lower roadway using a Caterpillar 315 excavator. Patterson is not being widened now, but Department of Transportation officials plan to eventually make it four lanes. As a result, the bridge is being fashioned with four-lane clearance in mind.
Twelve-in. (30 cm) pilings were sunk to stabilize the area of the abutments. Then the concrete abutments themselves and slope protection for each embankment were poured under the eye of bridge foreman Allen Horton. Some 50 cu. yd. (38 cu m) of concrete formed each of the two abutments and aprons in the first phase of the single-span structure. A retaining wall against the steep embankment on the east side of Patterson was added to the contract.
In the second phase, an additional 50 cu. yds. (38 cu m) will be poured. RMC Carolina Materials Inc. is the supplier. As the project moves along, more equipment crowds the site, including a Skytrac forklift, an Hitachi EX200 excavator, two Kobelco CK800 cranes and a Link-Belt LS108B crane. Amida Terex AL400 and Ingersoll-Rand 185 portable light units illuminated night work.
Finally, in February of this year, the tall I-beams arrived, shipped to Winston-Salem from a Stupp Bridge fabrication plant in St. Louis, MO. The girders are 6 ft. 10 in. (2 m) high and 140 ft. (43 m) long.
Those might not be especially massive dimensions, as building material goes these days. But once the first of the girders was swung into place, next to the old poured and prefabricated concrete bridge, the oversizing of contemporary materials was showcased.
The steel I-beam closest to the existing bridge towered over the old bridge like a 2-by-4 next to a Tinker Toy. How close the new and old structures sit wasn’t entirely anticipated by the company, nor by DOT engineers.
“We haven’t got any room on that side to build,” said Horton, the bridge foreman, anticipating problems last fall before the beams ever arrived. “It’s more aggravating than anything.”
But the company made it work. Using the two Kobelco cranes in a tandem lift, one above and one below, the I-beams were swung into place without incident if not without difficulty.
“We got it done,” Rowe said afterward, with a laugh. “I wouldn’t say there were no problems, but we got it done.”
Four beams will be placed in the first phase of the job. After the old structure is taken down, two more beams will rest on new abutments. That will create a steel foundation for a concrete roadbed about 53 ft. (16 m) wide.
The second phase of the $1.7-million project should be under way by May 1.
To demolish the bridge, Rowe will bring in a Komatsu PC300 with a Tramac 725 shear, as well as a Kenco “slabcrab,” which can break partly cut decks. A Komatsu-mounted hydraulic breaker completes the wrecking crew of equipment.
The project is scheduled to be completed Oct. 1. So far, the job has progressed on schedule, with minor setbacks like the unplanned relocation of a water line being offset by fewer wintertime down days than usual.
Smith-Rowe Inc. dates back to 1979 when Russell Smith and Carl Ray Smith formed a company in Mount Airy, NC, called Surry Bridge Builders. David Rowe had worked since he was 16 years old for H.B. Rowe & Co. Inc., another Mount Airy firm that was formed by his father, Henry Rowe, in 1960.
The younger Rowe became affiliated early on with Surry Bridge, which eventually became Smith-Rowe. He bought out Carl Ray Smith in 1983. Since then, the company has erected more than 200 bridges, all but a handful in North Carolina, as well as 50 box culverts and several retaining walls.
The firm’s 90 employees are spread this spring among projects in Alamance and Wilkes counties, in building four bridges on a major highway project near North Wilkesboro, and in Rockingham and Lexington.