Lake Champlain Bridge

lake-champlain-bridgeLake Champlain Bridge

New York State Lieutenant Governor Robert Duffy and Vermont Governor Peter Shumlin presided over the ribbon cutting of the brand new Lake Champlain Bridge, which connects Crown Point, N.Y., and Addison, Vt. on November 7, 2011.

The ribbon cutting marked the opening of this bridge, which replaced the former bridge that was closed in October 2009.

Lake Champlain Bridge completed in less than two years, demonstrates the positive power of states, agencies, and the public working together to achieve something remarkable.

Steel Structure
The new Network Tied Arch Bridge is a steel structure with an arch along the center span.

The bridge’s design makes it significantly safer than the previous structure and will ensure at least a 75-year service life. Key bridge components are designed to be easily replaceable to reduce maintenance costs. Travel lanes are 11 feet wide, with five-foot shoulders that will help accommodate larger trucks and farm vehicles, as well as provide ample room for bicyclists. Sidewalks are featured on both sides of the bridge.

The eight-story, 402-foot long, 1.8 million pound arch was constructed at Velez Marine in Port Henry, then floated down the lake and lifted into place on August 26. Building the arch on land was much faster, easier and cost-efficient than trying to safely build the arch high in the air above Lake Champlain.

New York and Vermont provided free, temporary ferry service in February for commuters, which has run continuously 24 hours-a-day, 7 days-a-week since. Operated by the Lake Champlain Transportation Company, the ferry drastically cut commuting time from the two-hour, nearly 100-mile detour and effectively reestablished commerce and emergency service along the corridor after the former bridge was closed. Ferry service will immediately be discontinued now that the bridge is open to traffic.

The Structure
The substructure is comprised of two concrete abutments and seven concrete piers that support the new bridge (the pier numbering starts on the NY side). The two concrete abutments, one at each end of the bridge, are founded on a series of 28 smaller micro-piles.

Piers 1 through 6 are founded on a total of 32 6-foot diameter drilled shafts in the lake. Near the NY shore, the casings are about 40 feet long, while in the deeper main channel areas near the mid-span of the bridge, the casings are over 100 feet long. Pier 7, the pier closest to VT, is founded on a spread footing on rock on the shore.

The 6-foot diameter steel casings were driven through the lake bottom soils until they reached bedrock. Once they reached rock, carbide cutting-teeth on the bottom of the casings were used to drill, or seat, the casing a minimum of 6 inches into the rock. Once seated in rock, the casings were emptied and cleaned of all soils and debris, and a 10- to 15- foot-long rock socket was drilled into bedrock at the base of the casing.

The casing was then fitted with heavy spiral steel reinforcement and filled with concrete. The steel casings were used to facilitate the drilling and installation of the reinforced concrete shafts, and although they will remain in place, they are considered an interim measure as they are not accounted for in the design calculations or required to support the bridge.

The completed drilled shafts were topped with a reinforced concrete pile cap, located at water level. The pile cap forms the foundation upon which the reinforced concrete piers were built. The 7 piers are essentially similar except the height of the pier stems varies depending on location. Once the piers were completed the steel girders were erected atop the piers.

The contractor secured a lease and all the required permits to assemble the center arch span at the Valez Marine in Port Henry, NY. On August 26, 2011, the arch was floated on barges to the bridge site and lifted into place on the ends of the NY and VT approach structures using a heavy lift method. A time lapse video of the float and lift is available here.

The center span was lifted into place without a concrete deck. This was done to limit the weight of the lift to just the structural steel components of the structure. To expedite the deck construction on the arch, precast concrete panels were used for both the roadway surface and the sidewalks, which are located on the outside of the arch.

These panels were staged on barges, lifted by crane to one end of the arch and moved into position using rollers. After the arch was loaded with the weight of the precast panels, the final VT and NY approach deck pours were progressed. The transverse space between each precast deck and sidewalk panel was filled with concrete in a series of small transverse closure pours. With all of the transverse closure pours completed and cured, the precast concrete deck panel system was post-tensioned.

The final work included the pouring of the longitudinal closure pours on the arch span, pouring the remaining sections of sidewalk on the approach spans, installing the remaining bridge rail and pedestrian fence, installation of the bridge joints, diamond grinding the arch deck panels to assure smoothness, sawcut-grooving the bridge deck to provide wet weather traction, installing the navigational, handrail and aesthetic lighting, and pavement striping.

Construction Team
The construction contractor on the project is Flatiron Construction Corp. of Firestone, Colorado. Flatiron brought a core team of approximately a dozen managers, but hired nearly 500 different laborers, many of them local residents from New York and Vermont. Local subcontractors and material suppliers were used as well.

The project to build the new bridge was completed by both the New York State Department of Transportation (NYSDOT) and the Vermont Agency of Transportation (VTrans) as co-lead agencies under an agreement between the states. Under this agreement, NYSDOT was responsible for progression of the project and costs were shared equally by both states.

As a result of the unprecedented collaboration between the partners involved in building the new bridge and the leadership of the two governors, construction was completed in just two years rather than the initial eight year projection.

Work to construct the new LCB began in June 2010, and continued through the 2010-11 winter season. The construction of the LCB encompasses three major work phases: the concrete substructure, the steel and concrete superstructure, and the approach roadways. The major work phases for the new LCB are depicted on the project information boards The preceding document link requires Adobe Reader.

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