Moving A Tennessee Mountain

By Steve Hudson | September 28, 2010

Moving 3.6 million yards of dirt and rock is a massive site work challenge, but that's exactly what Blalock and Sons is doing in Sevierville, Tenn.

Working not far from its home base in Sevierville, Blalock and Sons is handling this massive earthwork project for developer Kodak Land Partners. The work literally involves moving a mountain to prepare a site at Interstate 40 and Tennessee Highway 66 for a future multiuse development. The 195-acre site has about 8,000 feet of interstate frontage, and it's a highly visible site — thanks in part to the massive mountain which for years dominated the site.
According to Jim Nixon of Kodak Land Partners, the development will be the future home of a variety of retailers, restaurants, and other goods and services providers.

But first that mountain has got to be moved.

"Volume-wise," says Blalock Companies Vice President Allen Blalock, "this is the biggest retail site we have ever done."

"In all my years in this industry," adds Jim Williams of Caterpillar dealer Stowers Machinery, which has supplied much of the equipment being used on the project, "I've never seen anything like it."

John Anderson of project designer Site, Inc., based in Knoxville, adds that the mountain was critical factor in preparing the overall project design.

"The main concern," he says, "was to make sure that the site balanced."

Large-Scale Site Work

Work began last July 15 when subcontractor FNT Logging, based in Crossville, Tenn., began clearing the site. Hardwoods and pines were removed from about 150 acres of the site, with clearing completed in time for dirt work to begin just five weeks later.

With clearing complete, Blalock and Sons began to move dirt, with superintendents Mike Redmond and Jerry Graham overseeing the operation.

Subcontractor G.W. Wyatt Contracting, Jefferson City, Tenn., is also working on the site.

The mass excavation portion of the project, which has 18 months to wrap up, will literally move the mountain. The excavated material will be used to fill other portions of the site. In some areas, the total cut will be as much as 140 feet.

Initially, Blalock and Sons used Caterpillar 627 scrapers. The 627s quickly brought the site to the point where larger 631, 641 and 651 scrapers could move in so that serious earthmoving could begin. The largest pans can move more than 30 yards of material per run, a critical factor in meeting the project's schedule.

From the cut area, the scrapers transport the material an average of 3,000 feet to 4,000 feet, where it is discharged to build up low-lying areas of the site. Dozers (including Caterpillar D4s, D6s, D8s, D9s, and D10s) spread the material, which is then compacted by several Caterpillar 815 and 825 sheepsfoot compactors. As fill is placed, dozers also keep the slopes dressed.

During this phase of the work, crews moved about 25,000 cubic yards of material in a typical day.

Beating Steep Terrain

Moving a mountain inevitably involves working on some steep slopes, and Blalock and Sons has had to keep the steep terrain (and, more specifically, its impact on equipment operation) in mind in planning this project.

For example, the contractor is loading its scrapers as they descend from the top of the mountain. This allows gravity to assist in the loading operation. Once loaded, the scrapers leave their bowls down to slow their descent, saving wear and tear on brakes and transmissions.

Now and then, particularly as the cut progressed toward the underlying hard limestone, the scraper buckets would hang up on the occasional unseen large rock. When that happened, one of the large dozers would come to the rescue, nudging and sometimes slightly lifting the rear of the scraper to help it get over the subsurface obstruction.

Rocky Challenges

Initially, the site presented only dirt and weathered rock. However, as excavation moved ahead, the construction team soon began to encounter rock — first shale, then much harder limestone. The shale could be ripped with Caterpillar D9 and D10 dozers, and the ripped material was suitable for pickup and transport by the scrapers. The limestone, however, is much harder and requires a totally different approach.

"I'm estimating that 2.5 to 3 million yards of the total will be in the hard rock," Blalock says.

As excavation has shifted from dirt to rock, the focus has shifted from ripping to drilling and shooting. Likewise, the equipment line-up has shifted from scrapers to trackhoes and articulated trucks, necessary to load and transport the rocky material.

Blasting on the project is being handled by American Blasting. Initially, only occasional shots were required. However, as the excavation moved ahead and more rock was encountered, blasting became a regular part of the operation.

GPS Aids Excavation

Blalock and Sons believes in the value of GPS-based grading, and the company's Topcon GPS system has been in use from the beginning of this project.

"Initially," notes Allen Blalock, "we used rovers with portables to plot the site." As the work progresses, GPS-equippped machines will be used.

Overall, Blalock adds, the project is going smoothly.

"It's really a fairly straightforward job," he says. "It's just big!"