S.T. Wooten made up lost time, by moving a large amount of dirt in a very short time.
Choosing a driver has a whole new meaning at Cheviot Hills. The scenic public 18-hole golf course near Raleigh, N.C., was sold to Leith MLC Automotive LLC. This partnership is transforming rolling greens and sand traps into five car dealerships and a corporate headquarters, with design work by engineer of record WG Daniels & Associates.
Harrod & Associates Constructors Inc., headquartered in Raleigh, is the general contractor of the project and S.T. Wooten Corporation, based in Wilson, won the contract for the site work. As the site contractor, Wooten will clear the land, perform erosion control, install a culvert and do everything but utilities.
“We did work for the car dealership before,” recalled Mike Sciortino, area manager, “but this work was put up for bid.”
The bid on the on-site package totaled $7.6 million and an additional $3 million package was bid for off-site work: road widening along U.S. 1, signals, etc.
“We don’t usually do jobs this big,” Sciortino confessed, referring to the commercial division.
S.T. Wooten, founded in 1952, specialized in grading and paving in its early years. During the 1970s and ’80s, the company diversified, adding manufacturing facilities, utilities, structures and concrete products. Now headed by S. T. Wooten Jr., it consists of eight operating divisions: asphalt, commercial, quality concrete, ready mix concrete, heavy highway, structures and utilities.
In addition to its corporate office in Wilson, Wooten owns 13 asphalt plants and 17 ready mix concrete plants.
Par for the Course
Plans call for developing half of the project now: approximately 100 acres at the front of the property. Larry Wirth, representing Harrod, explained that the 100 acres in back are being left for future development, which might include a business park.
A benefit of dividing the job into halves is that it allows crews to install erosion control measures.
Erosion is an issue because they’re working so fast, Sciortino believed, but it was also a challenge because there are a lot of contour changes since the area under development was once a golf course. Leveling off the hilly 35-acre site was not only a big job, but it also created some issues.
“Everything on the pond side was a cut,” Sciortino noted.
“They took 30 feet off the height in the cul de sac area. There was a lot of dirt moved,” Wirth added.
Dirt work began in June 2009 and was completed by September. Sciortino estimated that they moved between 800,000 and one million cu. yds (611,643 and 764,554 cu m) of dirt. Approximately 70,000 cu. yds (53,518 cu m) of topsoil was given away to local landscapers.
“They screened it and removed it,” he added.
Substantial amounts of site dirt were reused on the project and Wirth noted that a lot of cuts and grades were done in order to avoid having to haul dirt away.
Moving a large amount of dirt on the sloping property wasn’t the only challenge. Water draining from the back of the property had to be contained in order to address erosion and other problems.
“There was a lot of water to handle during construction. It’s a big area to control,” Sciortino recalled.
A double box culvert was designed to help with runoff.
Two large basins were topped with fill dirt, using on-site dirt. An existing pond was made bigger and deeper. In order to do that, they drained it by pumping it out before enlarging it. They also raised the pond and riser 5 ft. (1.5 m) at a time.
“It was tough.” Sciortino said.
Then they installed wetland plants as part of the wetland mitigation.
Sciortino experimented with various methods of erosion control. Because of the steep 2:1 slope to the pond, he placed Fornit 20 – a geogrid, or turf reinforcement mat, comprised of polypropylene yarns crafted into a stable, interlocking pattern. Resistant to freeze-thaw conditions, soil chemicals and ultra-violet exposure, it helps stabilize poor soils by providing tensile reinforcement and soil separation. Crews hydro-seed through it. As the grass grows, it will work as a mat to hold the dirt in place.
Hitting a Wall
According to Staci Smith, of ACF Environmental, the project was designed with a modular block retaining wall.
“S.T. Wooten — Mike Sciortino specifically — proposed the Mechanically Stabilized Earth [MSE] retaining wall to the owners. S.T. Wooten and ACF Environmental worked with the owners’ representatives throughout many months to educate them on the wall, its installation and short-term financial and long-term green advantages.”
MSE walls are gravity structures consisting of layers of fabric or geogrid reinforcement. They provide high load-carrying capacity. ACF Environmental is a leading supplier of innovative geosynthetic solutions to the construction industry.
“We’re solution providers,” Smith summarized, “with 26 years of experience in design, installation and promoting products that facilitate construction. S.T. Wooten is one of our ’big’ customer in North Carolina.”
As a consultant brought in to add “value engineering” on the project, Smith’s duties included supplying information, technical expertise and material.
“We’ve done many walls on the east coast, from Maine to Florida. Mike asked if we could use the wall on this project. It would mean a huge cost savings, but he had to sell the technology to the owner and their engineer,” Smith stated.
Wirth admitted that the company had to be “sold” on the wall.
“We weren’t too sure,” he said.
To convince the owners, Sciortino took them to visit a few completed projects sites.
“They liked the overall ascetics and the green look of the project,” Smith indicated.
They couldn’t have been unhappy with the cost savings, either. Sciortino said the $1.6 million wall was not in the original budget, but installing it still allowed them to save the client money and added to the “green” aspect of the project.
“S.T. Wooten was instrumental in finding ways to save the owner money on this project,” Smith declared. “Mike Sciortino and S.T. Wooten thought ’outside the box’ to help the owner throughout this project.”
Smith calculated the savings of the MSE retaining wall: the material was cheaper — only four truckloads of wire baskets were needed for the face of the wall, as compared with 50 truckloads of modular blocks. This resulted in a savings to the environment due to less fuel used to truck in the blocks, less exhaust and less material taken from the earth. Using on-site soil was environmentally friendly and saved more money and man hours.
“The MSE wall is installed much faster than the MBRW,” Smith noted. “Fewer man hours [were] used to install the blocks.”
Sciortino estimated that it took half the time to put up. Construction of 101,000 sq. ft. (9.383 s m) of 40-ft.-tall (12.1 m) MSE retaining wall started on July 3, 2009, and was completed before the end of August 2009, and plants were installed in October.
Opting for the MSE wall instead of the modular block wall also allowed the use of on-site soil. Because S.T. Wooten had access to a significant amount of on-site soil, they also were able to save on hauling costs. Luckily for them, that plan worked: the soil has to be a specific type to work with this design and Cheviot Hills had the right kind of soil. As Wirth explained it, an MSE wall is “considerably less picky about the kind of fill dirt used; the requirements aren’t as stringent. Keystone [modular block] needs sandy soil so it doesn’t slide. Stabilizing keystone with fill was going to be a serious budget issue.”
Smith described the configuration as consisting of an 18 by 18 inch (45 by 45 cm) L-shaped wire basket on the wall that contains the soil for erosion control on the fascia. The benefit is that not only does the design allow for compaction and hold the earth, but it also offers more flexibility and “gives a little,” as opposed to a modular block concrete wall that can crack.
The environmentally friendly wall rises 40 ft. (12.1 m) in the back, but only 20 ft. (6 m) in the front by the road. Sciortino said a 50 percent slope faces the highway. In addition, there’s a river “buffer” around the wall, which complicated installation because no dirt or silt was allowed in the area.
“We couldn’t disturb it, so our wall is five to 10 feet off the fence.”
It’s part of a new City Greenway that hugs the base of the wall. The City was pleased with the choice of MSE wall because it decreases the “heat island effect: compared with a concrete wall and because S.T. Wooten used five native plants foraged from the forest to landscape the area.
“MSE walls are being used in more projects,” Smith said, “and a showcase project like this, located near the 540 loop around the city, gets attention. Already, other developers are stopping to look at it and ask about it. It’s a busy highway; there’s a lot of visibility.”
Sciortino expected site prep to be completed by March 31 and the road improvement done by August.
“We’ve been working every day that’s dry but Sunday,” he said.
Currently, he’s ahead of schedule, but it hasn’t been easy because their March start was delayed until May due to permitting issues and weather is always a factor.
Complimenting S.T. Wooten on its ability to make up time, Wirth recalled with amazement how crews used six hoes to fill trucks with two scoops.
“They moved an unbelievable amount of dirt in a very short time.”
Another challenge to the schedule has been utility relocation. To date, about 1,000 ft. (304.8 m) have been relocated and Wirth estimated that another 8,000 ft. (2,438 m) still needs to be moved.
“There is an incredible amount of fiber optics along Capitol Blvd,” Wirth said.
As one of the people who has had to coordinate scheduling so three different utility companies can move their lines, he pointed out that “it’s been extremely expensive.”
Sciortino worried about finishing the connector road, which is the last major thing to do, he said. Wirth said they’re racing to be ready when the Audi dealership is scheduled to open, despite a delayed start due to permits. In mid-March, crews were wrapping up work on signals, paving a left-turn lane and putting stone down for a right-turn lane into the project.
In addition to finishing the connector, Wirth said the rest of the off-site work — additional lanes, signals and an exit ramp off 540 — will take about nine months to complete. It also will take a lot of equipment. Sciortino listed equipment that has been on-site during the project, some of which they had to borrow from their heavy-duty division:
• Eight off-road 40-ton (36 t) trucks
• Two 345 Cat track hoes
• Two 330 Cat track hoes
• Two 322 Cat track hoes
• Three tractor and pans
• 615 scraper
• Four rollers
• Two 815s
• Two D6s
• Three D5s
• One D7 dozer
• Two water trucks for dust control
• One tower to fill the trucks more quickly
He explained that the water truck was used in an effort to reduce dust because the Toyota dealership was already open when they began working.
Looking ahead to the end of the project later this year, Wirth commended everyone involved.
“It’s a good team effort. We’ve been lucky to work with a good owner and design team on a really interesting project.”
Where golf carts once carried people from tee to green, soon different makes of vehicles will be the driving force.