Grading and Excavation Contractor

GPS and laser augmentation tackle site for massive Williamsburg retirement community.

By Jeff Winke

A mere 5 miles from the epicenter of American Colonial history lies the site for the 1,200-acre Colonial Heritage luxury retirement community and golf course being built by national builder US Home Corp. Who knows? Founding Fathers Thomas Jefferson, George Washington, and Patrick Henry may have tread on some of this old land in between plotting a revolution that would change the world.

All the site work on this Williamsburg, VA, location is being completed by Jack L. Massie Contractor Inc. “We’re responsible for all the earthmoving, grading, and roadwork from the entrance gate to every building pad and cul-de-sac right through the rough grading of the golf course,” says Scott Massie, site supervisor. There are also retention ponds to be dug and service roads to be placed through thick forest.

GPS Speeds the Work
The project was started in 2002, and it could take as long as 15 years to complete this massive community. The project is huge. Less than three years into it, Jack L. Massie Contractor has already moved more than 1.5 million cubic yards of dirt.

The soil is moisture-sensitive and weather has a major impact on the work. “The GPS helps us work around the inclement weather by helping us complete the work quickly and correctly the first time,” says Jeff Hamm, field engineer. “The demand for speed does require some undercutting on this project. On a roadbed for instance, we will grade the subsurface and then do a proof-role with a fully loaded dump truck to check for sponginess or sinkage. We’ll block off those trouble spots, take out an amount of soil, and then lay in some CTA to give that area extra strength.”

Horizontal and Vertical Control
The 45-member crew has several pieces of heavy equipment at work on the site: two John Deere 850C Series II crawler dozers for rough grading, two John Deere 700H crawler dozers, and a John Deere 750C Series II crawler dozer—all of which are equipped with Trimble SiteVision GPS grade control systems. The two 700H dozers also have an integrated laser augmentation for GPS 3D grade control; thus the GPS performs the horizontal control and guidance, while the laser system ties down the vertical.

“For several years, we’ve been using GPS grade control systems,” Massie says. “It was a big step to change over to stakeless grading, but it has saved us money, increased our efficiency and productivity, and gives us better, more reliable results.”

Massie points to the completed entrance gate area to Colonial Heritage. The 5-acre beautification area features massive, multiple rolling hills; landscaped curves, dips, knots, and slopes; and an irregular-shaped pond with fountains. “This was all graded using a single dozer without a single grade stake. It is probably one of the most dramatic displays of grade control provided by the Trimble system,” Massie says. “If you had seen it before we started working on it, you’d be amazed. I know we stood there, scratched our heads, and said, ‘OK, we’ll let the 3D plan from Trimble’s Terramodel software control our machines and see how it shapes up,’ and you can see the result is absolutely gorgeous. It’s a bit amazing to think that a piece of heavy equipment with a hard steel blade cutting across earth could actually produce all these smooth contours.”

“The dual-mast system with the Trimble system gives us an advantage,” states Hamm. “It gives us the ability to switch our focus point to any location along the blade—this helps us save our road crowns and building pad corners. Every building pad is certified, so if they were to give us a failing report we would need to re-grade the pad, which is time and money. However, with GPS that has not happened.”

The residential mixture at Colonial Heritage calls for flat-pad, half-step basements and full basements. The houses themselves are tucked into rolling hills with up to 6-foot step-downs from pad to pad. The Trimble laser augmentation has been critical to the efficient completion of the step-down pads, according to Massie. “With laser augmentation we can literally get pads within three-hundredths of a foot of tolerance—it is the tightest system we’ve ever used.”

“We use both the flat-plane and slope-plane capabilities of the laser augmentation system,” Hamm adds. “Setting the slope with the laser system is very simple. I can rotate the laser, locate the benchmark, and the operator will then have the azimuth, which is the direction from which the laser is coming, and with that the operator can set the mast receiver.”

Jack L. Massie Contractor uses the laser augmentation system on all of its stonework. “We’re absolutely pleased with it,” Massie says. “We’ve used it on all of our CTA and crushed gravel work.”

Operators Are Empowered
Trimble SiteVision GPS has given the operators, almost “instantaneously,” team-leader responsibility, Massie explains. “The operator has the plan view right there in front of them. They’ve got the slope, cross section, everything. Since they’re the ones that know what’s going on and, in a sense, manage their section of the site, the machine operators feel good about the responsibility. It can be a beautiful display of synchronized movement to see a dozer and an excavator working together.”

“One big advantage of SiteVision GPS is that we can run at night,” Hamm says. “Because our weather is so unpredictable, we’ll play catch-up if need be and run into the evening.”

Both Massie and Hamm point out that they have felt comfortable tackling a huge project such as Colonial Heritage because of the “advantage of GPS grade control and the laser augmentation system.”

Massie has also “seen the dedication level of our crew improve since they know that they are working with the latest, greatest improvements in technology. And we also know we will never go back to the traditional methods of staking.”

Jeff Winke is director of public relations and special projects at High Velocity Communication in Waukesha, WI.

GEC - January/February 2007

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