The Texas-sized Dallas High Five project is ahead of schedule with a little help from Italian technology.

Because of a joint venture between San Antonio-based general contractor Zachry Construction Corp. and Italian engineering and construction company Rizzani de Eccher, bridge segments on the ambitious $261 million Texas Department of Transportation project are being installed more easily and much quicker than in the past.

"Our planned completion is January 2007, but the contractor appears to be ahead of schedule," said Larry Tegtmeyer, northwest area engineer in Dallas County for TxDOT. "I think part of that has to do with implementation of the segment erector."

The 101-ton erector is the first of its kind to be used in the United States. Shipped from Italy in segments and then assembled onsite, the $1 million piece of machinery features equal parts hoist, flatcar and truck. It was designed and constructed by Deal SRL, a subsidiary of Rizzani de Eccher, ranked 136th in Engineering News-Record's top 225 international contractors in 2002.

The segment erector is moved to ground level near the bridge, then hoisted to the top of the bridge pier via crane. The erector, which measures 97 ft. long, 38 ft. wide and 37 ft. tall., can then hoist individual precast bridge segments from the ground into place atop bridges. It is capable of lifting segments of up to 70 tons at a rate of 30 ft. per minute.

Once the segment reaches the top of a pier, the erector can travel from end to end along the cantilevered pier to the point of segment placement. "That's the best thing about the erector," said Zachry project manager Clovis Glenn. "The ability to move side to side once it's on top of the pier greatly reduces the impact to traffic moving underneath."

TxDOT statistics show more than 440,000 vehicles pass through the area daily - about 260,000 on Interstate 635 and another 180,000 on U.S. Highway 75. "Any other method (of erecting the bridges) would have impacted the traffic a lot more and that is something we are especially sensitive to on this project," Glenn said.

Motorists traveling in the High Five construction zone since the project began in January 2002 know that traffic has been impacted to varying degrees. But the utilization of the segment erector seems to be having the desired effect.

"When they first started, it was a nightmare getting through here," said motorist John Erickson, who commutes daily through the area from his home in Grapevine. "There were lane closures and traffic jams that just made your head pound on a daily basis. In the last few months or so, though, those tie-ups don't seem to be quite as frequent. Still, I can't wait until they're done."

Zachry has a contract incentive that calls for a bonus of $32,000 per day (up to $11.5 million) for finishing the project earlier than its expected five-year completion. In late March, the company had more than 400 employees on the jobsite not including subcontractors.

The pace of the project as well as the pace of Zachry's workforce helped to keep more than 30 TxDOT project inspectors hopping. "Our main task right now is to try and keep up with what Zachry has done," Tegtmeyer said with a smile.

Center Of Activity

As the project entered the warmer spring months, most of the construction centered on frontage roads and bridgework.

"We are diligently trying to get the Coit Road bridge completed by late this summer," Glenn said.
"That way, we can have all the lanes on Coit Road open to where motorists can use that roadway as an alternate to U.S. 75. That will allow them to essentially bypass the entire construction zone."

Coit Road is a major north-south artery located west of the IH 635-U.S. 77 intersections and many motorists already elect to take the roadway south to U.S. 77 to try and avoid the construction zone.

In addition to Coit Road, work has continued on the direct connector from eastbound IH 635 to northbound U.S. 75. Tegtmeyer said that he is hopeful that connector will be completed and open to traffic by the end of this year. "That will be the first direct connector that we will open and will mark a rather significant accomplishment in the overall project," he said.

Zachry has constructed a pair of onsite batch plants, which will produce approximately 325,000 cu. yds. of concrete for the cast-in-place structures and paving alone, enough to fill a football field 200 ft. deep.

That yardage, however, does not include precast concrete for reinforced concrete pipe, precast retaining wall panels or precast bridge beams. A casting yard is located near the southeastern portion of the project with more than 130 bridge segments already in place by the end of March and another 100 awaiting installation.

All roadways through the project will feature lime-treated subgrade and 6 to 8 in. of asphalt base topped with 12 to 14 in. of concrete pavement. Zachry will produce and pour the concrete while Dallas-based Austin Bridge & Road will handle placement of the asphalt. D'Ambra Steel Services of Houston will supply and install reinforcing steel while Justin-based Renaissance Contractors Inc. is the concrete pipe subcontractor.

Staying Ahead Of Schedule

Even though the project continually stays ahead of schedule despite its size, obstacles remain.

"I think the most challenging aspect of construction so far is getting the frontage roads built and dealing with utilities," Tegtmeyer said. "We have a wide array of utilities throughout this area and a lot of them were relocated prior to construction.

"But that doesn't mean that there still aren't utilities out there that have to be moved again. And we have to deal with every conceivable company out there - TXU, Encor, TXU Gas, numerous fiber optic lines, cable TV, phone lines, AT&T and SBC. The logistics of all that can sometimes get a little tricky."

Still, with Zachry crews working at least five days each week and often more, the project capped its first year about 8 percent ahead of schedule.

"Now what exactly does that 8 percent mean?" Tegtmeyer said. "It simply means that from now until completion, if everything goes the way it's supposed to, we could be finished around six months early. I can tell you that the project will not be complete a year early, but I can also tell you with relative certainly that it won't take the entire five years to complete either.

"For the past couple of months, I wouldn't say we have been cruising on this project, but we have been getting things accomplished and getting after business. There is no doubt I would term this project a success so far. But that presents us with a fairly big challenge the rest of the way.
We've raised the bar pretty high in this first year."

Once completed, the five-level interchange will include four lanes of travel north and southbound on U.S. 75; a frontage road box created by the intersection of continuous east-west and north-south frontage roads throughout the interchange; five lanes of travel east and westbound on IH 635 with two lanes each way of barrier-separated HOV lanes; direct connection ramps from U.S. 75 to IH 635; and direct connection ramps from IH 635 to U.S. 75 and reversible HOV lanes to and from IH 635 West and U.S. 75 North.