Tue July 09, 2002
Giles Lambertson
The 110-acre (44.5 ha) site north of Charlotte, NC, on Interstate 85 was tree-covered as 2002 began, but beneath all the roots and top soil was rock. Lots of it.
“Just about all the million yards is weathered rock,” said Brad Heavner, alluding to the volume of shale and earth to be moved on the project that will become the Northlite Shopping Center.
Heavner is vice president of operations of Scurry Construction Inc., the general site contractor on the job. The rock is not a problem for Scurry. In fact, the company probably has the job because the rock is there.
“That’s probably what swung the contract to us,” Heavner said six weeks into the project. “The way we move dirt gives us an advantage in the bid process.”
Heavner declined to elaborate on the company’s grading methods except to say that the company is able to get the rock moving with little or no use of explosives.
Heavner acknowledged that 100,000 cu. yds. (76,455 cu m) of genuinely impervious terrain is, indeed, “potential shot rock.” But he said most of the remaining 900,000 cu. yds. (688,099 cu m), “We anticipate being able to excavate without shooting. We’ve found the site to be just the way we thought it would be.”
The work site is situated a few miles north of Charlotte between Concord and Kannapolis. The two jurisdictions actually bump within the acreage that Scurry crews are reshaping.
The shopping center will feature Wal-Mart, Sam’s Club and Kohl’s outlets. Another two dozen outparcels, including a Holiday Inn, also will be developed, creating a critical mass of stores that developers are hoping will entice big spenders, or at least many small ones. The main site preparation contract is for $10 million. Scurry is hoping to win some of the outparcel work, too, which could mean up to $4-million more in contracts.
So far the only blasting on the job has been for short stretches of utility trenching. The depth of the trenches made it necessary: That’s because while the first level of digging for utility lines is through shale, “down 15 or 20 ft. is a lot tougher rock,” Heavner said.
“Down” in some places means 55 ft. (16.7 m) below original grade. The final grade is 30 ft. (9 m) below original grade, while utility grades are another 25 ft. (7.6 m) below that in places. All this digging and filling is transforming the rolling terrain into something more suitable for buildings and parking lots.
It adds up to a lot of earthwork. By mid-May, some 400,000 cu. yds. (305,822 cu m) of dirt had been moved on 80 cleared acres (32 ha). Clearing was subcontracted to Wes-Ben, a Robbinsville, NC, contractor.
Scurry also laid 4,000 to 5,000 linear ft. (1,219 to 1,524 m) of pipe by mid-May, principally 36-in. (91 cm) concrete lines to carry away storm water. Hydro Conduit, of Charlotte, supplied the pipe.
Doing much of this heavy work are nine John Deere excavators, including 450 and 550 models. They are digging away dirt and rock and loading it onto Volvo A30 and Caterpillar D400 articulated trucks. Eight of the trucks are on site.
Alongside this hauling, a Caterpillar D6R and John Deere 850 push dirt and two Cat 815s compact it. In all, approximately 30 pieces of equipment work the job. Scurry is leasing some of the earthmoving machinery from a James River Equipment office in Charlotte.
Working six days a week, Scurry crews are taking advantage of favorable weather. Though the region needs rain, the project doesn’t. Heavner reported that in the first six weeks, work was stopped by inclement weather just once, a Saturday.
This combination of good-working weather, quality personnel and equipment, and a well-organized plan has the project running a full month ahead of schedule, Heavner noted.
That is significant because it was bid as a 10.5-month job. When a December start date got pushed back to April, however, it became a seven-month project.
Now, if weather and good fortune hold, it might turn out to be a six-month job. Rough grading should be finished by Aug. 1, leaving some utility work, paving and finish grading. The Sam’s and Wal-Mart sites are to be finished by Nov. 1, with the Kohl’s site by Dec. 1.
Bringing the site to grade is a hi-tech undertaking for Scurry. The company uses a global positioning system (GPS). The Cat D6 is outfitted with a GPS unit that guides the operator and blade from a satellite base station set up and calibrated on site. A computer program for this site was developed back in Scurry headquarters in Cornelius, north of Charlotte, and loaded into the machines on site. Signals from the base station direct the work of both the Cat and a backpack GPS unit used for incidental staking.
For approximately two years, Scurry has relied on the satellite and laser technology to establish the contours of its work sites. The company began to employ it after Scurry was approached by Spectra Integrated Systems, a Charlotte-area firm. Heavner, Bill Scurry, who is president of Scurry Construction, and other policy-makers in the firm listened to the presentation and were persuaded that a GPS system would meet their needs.
Heavner explained that the company specializes in residential and commercial developments, some of which incorporate a variety of step-down grades. That used to mean a lot of surveying and staking. Not any more.
“You drive through our sites today and there are just a handful of stakes, mostly utility stakes,” Heavner said. “We save a lot of staking and grade checking.”
Confidence in the system has grown. A week or two of using the device was necessary before operators became believers in the new technology. In fact, the company had a surveyor on the first few projects double-checking for accuracy.
The same caution was exhibited by the industry as a whole. Scurry was the first Spectra Integrated customer in Charlotte, but reliance upon GPS is growing in the western North Carolina region. Joe McNamara, a Spectra vice president, said in 18 months the number of customers has grown to 35.
Construction applications are growing, too. Scurry uses the GPS on its Caterpillar dozer, but the system is available for scrapers and graders. It soon will be part of excavator operations.
In fact, Trimble Inc., which is a machine control product manufacturer, and Caterpillar Inc. announced this spring an agreement to develop a new generation of electronic guidance devices for construction, mining and waste industries equipment.
So with machinery coming off production lines with GPS receivers embedded in them, more and more contractors will be looking to companies like Spectra to connect them. The popularity of the new technology is as simple as a bottom line, said McNamara.
Savings to contractors come three ways: (1) production savings, because dirt is just being moved once; (2) materials savings, because the grade is maintained across a site, not just where stakes used to be placed; and (3) labor savings, because stake placement and survey follow-ups are eliminated.
Spectra Integrated Systems has North Carolina offices in Charlotte, Greensboro and Raleigh.
Scurry Construction was incorporated just seven years ago by family members Bill Scurry, Gail Scurry, who is secretary/treasurer, and William P. Scurry Jr. The latter is project manager on the Northlite project, while Robert Miller is project superintendent. Heavner came aboard Scurry Construction in 1997. It has grown from 10 employees in 1995 to more than 70 today.
The company specializes in turnkey site work on projects within a 50-mi. (80 km) radius of Charlotte. It does in the neighborhood of $20 million of business each year, most of it residential and commercial site work. A typical year has Scurry bringing to grade several commercial sites and 15 to 20 multi-housing sites with an occasional Department of Transportation job thrown in the mix.
This story also appears on Construction Equipment Guide.