Complex foundation drilling job in N.C. is contractor's niche-type project.



Back side of the dam. Note the access platform.
We caught up with Scott Dodds, manager of the drilling and grouting group at Brayman Construction Corp., in his home away from home – North Carolina. “Since we’ve been in the North Carolina area for some time, we’ve been bouncing from job to job and collecting equipment and tooling that pretty much has become our North Carolina stuff,” he explains. “It’s like we have a mini yard down there.”

Dodds tells us that Brayman, headquartered in Saxonburg, Pa., “has been in business 50-plus years and has about 350 employees. We’re a heavy highway contractor specializing in concrete structures, bridges and foundation work. Regionally, Brayman is a bridge and structure company, and we’ll travel within a three or four hour radius of Pittsburgh with our heavy construction, which is a main core of the company. Our foundation division travels pretty much anywhere from the Mississippi to the East Coast. We tend to stay out of the major metropolitan areas like New York or Boston but most everywhere else, we’ll take a look and see if the work is right for us. We have jobs right now in Atlanta and Baltimore, so we’re spread out pretty good.”

Installing the strands.
We visited Dodds in Hickory, N.C., where Brayman was doing foundation drilling to renovate Oxford Dam. “Duke Energy, owner of the dam, is required by the Federal Energy Regulatory Committee to complete a study for all of their hydro-generation dams to make sure they meet certain probable maximum flood (PMF) requirements,” Dodds says. “When this analysis is done, it is then determined what type of upgrade the dam needs to maintain that PMF. This dam’s upgrade required installation of approximately 75 high-capacity dam anchors through both abutments and through the spillway section, as well as construction of a new emergency overflow spillway section. As part of that emergency overflow spillway section, a new soil nail wall was constructed, which acts as a channeling device for the water.

Anchors were drilled between 100 feet and 160 feet deep.
“The soil nail wall is about 300 feet long and has a maximum height of 50 feet. So the total square footage of the wall is approximately 10,000 square feet. It’s designed to retain the hillside behind and act as a channeling device to keep the water confined to the river channel itself should a PMF flood ever occur. There were approximately 370 soil nails in 10,000 square feet of Shockcrete 6-plus inches thick.

“On this particular job, we’ve employed three different drill rigs. The EGT 5000 is doing the drilling and installing of the soil nails. We also have a Casa Grande C-8 drilling and installing high-capacity dam anchors, and a Davey 527, which is a smaller-style rig, to do the dam anchor work out on a platform we’ve built.”

There are 75 of those dam anchors – 58-strand epoxy-coated anchors drilled anywhere between 100 feet and 160 feet deep. Brayman has three crews working on this project – one installing the high-capacity anchors, one constructing the soil nail wall and the other doing the concrete pouring, forming and placement work on the spillway.

Building the emergency overflow section.
To get the work done on the backside of the dam, Brayman built a special platform to provide access. “We’ve got a small 40-ton rough-terrain crane that will sit on the apron of the spillway to lift and place materials and equipment up onto the platform itself,” Dodds explains. “We’ll put the small Davey 527 drill rig on that platform, along with a small carry deck crane. Those two pieces of equipment will handle the drilling and installation needs, along with an uncoiler and the stressing jack. That’s all you really need up there to do that work. We’re drilling a 12-inch diameter hole 140 to 150 feet deep. I don’t want to say the drill is self-contained but we really don’t need any lifting services to get along with the drill. The lifting services are there to support the installation of the strand into the hole. So the drill itself is maintained by a drill operator and two laborers to add and take off drill rods as the drilling proceeds. We have it set up to drill half of the spillway. There are 40 anchors on the spillway so we built platform out to cover half of them at a time. We’ll do the first 20, then tear down the platform and reset it out ahead of us and do the other 20.”

The project got started in October of 2002 and is scheduled to go through this November. “The weather has caused some trouble but production has been such that we’ve been able to maintain our schedule to this point,” says Dodds.

The 14-month project is right on schedule.
This was an average-sized job for the company – “one of our niche-type jobs,” Dodds remarks. “We’ve done five other dams and a bridge demolition for this client.” The job was negotiated. Fifteen to 20 percent of Brayman’s jobs are negotiated; the rest is hard bid. “Duke negotiated this one because of the complexity of it and our ability to self-perform most of the work. They have future contracts that will be out for bid later this year. We plan to do more work for them – and that will make our percentage of negotiated work go down, unfortunately.” That’s OK. Dodds and Brayman will feel perfectly at home in the Tar Heel state.