ADDISON, Vt./CROWN POINT, N.Y. — Contractors have completed most of the underwater sub-structure of the new Champlain Bridge and will work through the winter on some of the more visible elements of the new span that is slated to be finished by Oct. 9, 2011.
New York State Department of Transportation (NYSDOT) officials on Thursday provided their first substantial, on-location update on progress in building the new bridge, a $70 million project being undertaken by Colorado-based Flatiron Construction.
Flatiron has 500 days in which to replace the former Champlain Bridge with a new, modified network tied-arch span that will once again unite West Addison, Vt., with Crown Point, N.Y.
Vermont and New York transportation authorities closed the 80-year-old bridge on Oct. 16, 2009, and ultimately imploded it last Dec. 28 after it was deemed unsafe and unsalvageable.
Flatiron began work on the replacement bridge in June, focusing first on deep foundation work on the span’s substructure. That work included drilling 32, six-foot-diameter shafts as groundwork for the six massive piers that will support the massive bridge in the water. A seventh pier will be located on the Vermont shore, on rock.
John Grady, regional construction engineer for the NYSDOT Region 1, pointed to the nearly completed concrete abutments on each side of the lake as workers were being ferried by motorboat to various work platforms and cofferdams (water-tight enclosures) along the length of future bridge site. There are currently 100 to 120 workers laboring in two 10-hour shifts a day to get the job done.
“We have really reached a critical milestone,” Grady said, alluding to an imminent transition to above-water work at the project site. The most exciting part of that above-water work will occur next summer, when the main arch — which is being pre-fabricated off-site — will be floated down the lake on a barge and lifted into place.
In the meantime, workers have been laying the deep groundwork for that momentous occasion. That has included installing the drill shafts that are in some cases 100 feet deep, according to Grady. The shafts are drilled through the mud and into the rock, then filled with concrete.
“We now have to build those pier caps that span over those pods of four or six shafts, depending on what pier you are at,” Grady said. “That work is now under way.”
Once the piers are in place, work will begin on the approaches to the span, starting on the Vermont side.
“We will start spanning across with our approach steel, building from both ends, with the goal of sometime later next summer having those approaches both in and our arch span … lifted into place,” Grady said.
The arch span will then have to be decked.
Grady pronounced the project on schedule and on budget, which is good news for commuters as well as for Flatiron. The company’s contract includes a provision requiring it to absorb the costs of the adjacent, temporary ferry service (around $30,000 per day) for any period that exceeds the 500-day limit. At the same time, the contract provides a financial incentive for Flatiron to complete the work in less than the 500-day limit. The NYSDOT has several officials on-site doing quality control inspections.
Grady reported good public support and decent weather since the project began. He said work can proceed through inclement weather, but added wind and cold temperatures are laborers’ worst enemies. He noted work had to be shut down for a few days this past summer when wind and high waves disrupted work on the lake.
“When the wind comes out of the north, it’s just atrocious,” he said.
Flatiron workers are using the remnants of four of the old bridge piers as staging areas for work on the new span. Those old piers will ultimately be removed. Steel from the former bridge has been sold to salvage yards in Albany and Montreal.
Grady noted the new span is designed for a minimum lifespan of 75 years.
“The new bridge is being designed with a lot of protection measures, both in the underwater elements and the steel elements,” Grady said, noting the former bridge’s concrete piers were not endowed with metal reinforcement. “The piers in the water are built with a certain canted angle, so that ice, as it moves against it, falls back and breaks off. All of these piers are armored with granite … for abrasion protection.”
Concrete elements of the span will feature ample steel reinforcement, according to Grady, who added that steel exposed to the elements will feature a “flame-coated metalizing product” (primarily aluminum and zinc) that will ensure the bridge is protected without the use of paint.
Vermont officials said they are pleased to see progress on the bridge. Grady called the project around 25-percent complete at this point.
“Our goal from the beginning was to complete the deep-water work before winter, and I commend all who worked on the project for achieving this important objective, especially our partners at the NYSDOT who are leading the construction effort,” said VTrans Secretary David Dill. “We now will move onto the next phase of construction right on schedule.”
Reporter John Flowers is at email@example.com.