Tunnel Trend

Company sees high-rise trend toward tunnel-forming technique

By Scott Judy

Concrete contractors are in great demand throughout the Southeast, and, as in all sectors, competition is fierce among the top firms.

And it's often these specialty contractors that feel the greatest schedule and budget pressures from owners, developers and general contractors. That means success is all about being as efficient, quick and safe as possible.

With those pressures in mind, one of the Southeast's fastest-growing concrete forming firms, Total Concrete Structures of Atlanta, is in the process of adding another trick to its trade. Though the company performs most of its work with conventional framing, it is nevertheless touting the use of tunnel forms as a way to both speed construction and increase quality.

Already responsible for the construction of the world's tallest tunnel-formed project, the 44-story Paramount at Buckhead apartment building in Atlanta, the company is presently spreading the word on this technique with ongoing and upcoming projects in Florida.

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Though tunnel-forming has typically been used for low-rise structures, such as garden apartments and military housing - and one of the company's present tunnel-form projects is a low-rise structure - it's in the high-rise market that Total Concrete sees the greatest potential for growth.

"Starting two or three years ago, it's gotten real popular in high-rise construction, as more and more owner/developers see the rapid construction pace and better quality," said John Stull, president for Total Concrete Structures. He added that the enhanced quality is found in the smoother finish produced by the use of a manufactured steel form.

Stull said that due to the smoother finish, developers can reduce other costs by eliminating some metal stud and drywall work and applying painted finishes directly to the concrete.

In addition to its current low-rise project, the $15 million European Village in Palm Coast, Total Concrete will be building the 35-story Vue at Lake Eola in Orlando with tunnel forms, and it is in preliminary negotiations for another project in the Southeast that would easily eclipse the firm's previous world record for height.

Benefits

The European Village project is superintendent Dennis Hitson's first experience with tunnel forms, and so far, he's sold on it.

"Tunnel forming is a lot faster than conventional framing," he said. "With tunnel forms, I pour every day, and I pour my vertical [columns and/or walls] with my horizontal. If you've got typical bays, tunnel-forming's the way to go."

The daily repetition of the system makes it easy for workers to learn, Stull added.

"Once you put [the form] together, you don't ever touch it," he said. "You drop it, pull it out and set it back in the next location. [The crew] does the same thing, every day, at the same time. It's like clockwork."

Still, Hitson admitted to some limitations.

"Sometimes it's a headache, but the design pretty much tells you where your headaches are going to be before you ever put your first tunnel in," he said.

Additionally, said Stull, "It takes a lot of planning in the initial stages of the job. The most cost-efficient way of handling a tunnel-form job is to design the building around the tunnel-form [method]."

For example, the architect on the Vue at Lake Eola project had never designed a tunnel-form project. By working with the concrete contractor in the initial stages of design, the team was able to shave an estimated $3 million off the construction costs and have the concrete work completed six months faster than with conventional framing.

"If the owner and design team are willing to listen, it's well worth it," Stull said. "It's unbelievable how much money you start to save. But you've got to design the building for it."

Stull said the ability to use post-tensioning systems with tunnel forms - as will be the case on the Vue - is a further reason for this method to expand in popularity.

European Village

European Village is Total Concrete Structures' first project in Florida. The four-story condominium project consists of three separate buildings sitting on top of a single, underground parking structure. The first floor is dedicated to retail spaces.

Total Concrete Structures has a $4.6 million contract and is constructing all of the concrete work as well as effectively performing as GC on the project.

"We designed the building, and the structural engineer works for us, so it's a design-build contract," Stull said. "We helped coordinate the sitework, the grading work. We're kind of their little general contractor out here."

The developer, Harborside Development, has separate contracts for exterior and interior finishes.

The company broke ground in February and expects to be finished with its work by September. The entire project should be complete by January.

The concrete firm sold the owner on the quality it could attain with the tunnel-form system and the cost savings it could achieve through reduced drywall expenses. Still, Stull said that because of problems with concrete availability, it probably would have been better to frame it conventionally.

"With a tunnel form, you've got to pour every day," he said. "If you don't pour you don't have a place for your guys to go to (work) tomorrow. That's been our biggest problem. If I had to do it all over again, I probably would not do it as tunnel forms."

Stull said the process has saved the owner four to six weeks on schedule but has cost more than originally estimated due to the cement shortage.

Over a roughly two-month timeframe, concrete deliveries shrank from as much as 650 yds. per week to 200 yds. at the most, Hitson said. With typical pours about 80-90 yds., essentially this meant that instead of pouring every day, the company was only able to get concrete two days a week.

To keep on schedule, Total Concrete has brought in additional crews to conventionally frame portions of the third building being erected, while the other crews catch up on the second building.

Concrete availability concerns started going away in July, and the firm expected to meet its original Sept. 8 deadline.

Useful Sources:

For more information about Total Concrete Structures' past projects, including tunnel-form projects, readers may visit:

http://www.totalconcrete.com/index.html

Project Team:

Owner/Developer: Harborside Development
Structure Contractor: Total Concrete Structures, Atlanta
Designer: BFY Associates, Daytona Beach
Structural Engineer: Sa-Tech Engineering, Boca Raton
Electrical Contractor: Carter Electric, Daytona Beach
HVAC Contractor: D.G. Meyers, Ormond Beach