Tappan Zee Bridge

December 2016 – UPDATE
In October, the first of the 7,000 precast concrete deck panels were installed on the Tappan Zee Bridge, the 3.1-mile-long, $3.9 billion bridge-construction project in New York. The panels represent a record-setting $70 million worth of precast concrete for the project and will serve as the driving surface for the bridge when it is ready to open in 2016.

The first panels were installed on the northbound span along a curve on the steel girders. The panels are 12 feet long and 11 inches thick and range in width from 22 to 45 feet. They weigh up to 74,000 pounds apiece. The approach spans will use 6,000 panels in all, encompassing about 2 million square feet, while the main span features 950 panels.

Each piece has 1’4” of rebar protruding from each side, which creates widths that restrict transportation times and require escorts, according to Joshua French, sales engineer and project manager at Fort Miller, the precaster for the panels on the main span. Unistress Corp. is casting the panels for the approach spans. The pieces are transported on an angle to provide the best maneuverability.

By October 28, 70 panels had been installed. The main-span panels, scheduled for installation in 2016, are designed to lock together, speeding installation.

The first crossing is planned to open in December 2016. Unistress estimated that by the end of October it had produced 1,400 panels, fabricating about 18 per day. Galvanized steel is being used for reinforcement as part of stringent requirement that also include a high-strength concrete mix. The designers developed their own concrete mix design to meet the challenges of the long spans over the river, using a rigorous preproduction testing method to determine the best option.

The twin-span, cable-stayed bridge replaces the original structure, completed in 1955. The new design comprises a steel substructure with eight traffic lanes, four breakdown lanes, and a bicycle and pedestrian lane. The bridge will incorporate a state-of-the-art traffic-monitoring system and is designed to handle light-rail or commuter-rail trains in the future. The precast concrete panels will form the driving surface of the bridge.

The bridge is being designed and built by Tappan Zee Constructors, LLC (TZC), a consortium of design, engineering, and construction firms, including Fluor, American Bridge, Granite, and Traylor Bros., along with key design firms HDR, Buckland & Taylor, URS, and GZA. TZC is working closely on the project with a team of employees from the New York State Thruway Authority and the State Department of Transportation. It is being designed to achieve a 100-year service life.

The $70-million fabrication contract represents a record for precaster Unistress Corp., says Perri Petricca, president. The panels are straightforward in design, he notes, “but with the requirement of a 100-year design life, they are being manufactured to exacting standards.” Achieving that goal includes such measures as fabricating the panels with high-strength, high-performance concrete and using galvanized-steel reinforcement.

Meeting the tight 18-month schedule, which began in August 2014, required Unistress to invest $6 million in expanding its facility and adding more than 100 employees. The goal is to produce 18 panels per day, with another six to eight months required to complete delivery following casting. The panels will be transported to the Port of Coeymans near Albany, where they will be loaded onto barges and shipped to the job site.

“We are thrilled to have this project as a catalyst for expanding our bridge division and creating new jobs in our community,” says Petricca. “This is a demanding project, both in scale and complexity. The general contractor spent months evaluating proposals from precast producers across the country to make sure that whomever they selected could provide 6,000 pieces on a tight schedule, designed and built to last 100 years.”

 

August 2014
The new 3.1-mile-long Tappan Zee Bridge, at $.3.9 billion the largest bridge-construction project in New York state history, features a record-setting $70 million worth of precast concrete deck panels. Fabricating the 6,000 panels on the tight schedule has required the precaster to expand its facility and hire another 100 workers. The first span is scheduled to open in 2016, with all work completed by 2018.

The twin-span, cable-stayed bridge replaces the original structure, completed in 1955. The new design comprises a steel substructure with eight traffic lanes, four breakdown lanes, and a bicycle and pedestrian lane. The bridge will incorporate a state-of-the-art traffic-monitoring system and is designed to handle light-rail or commuter-rail trains in the future. The precast concrete panels will form the driving surface of the bridge.

The bridge is being designed and built by Tappan Zee Constructors, LLC (TZC), a consortium of design, engineering, and construction firms, including Fluor, American Bridge, Granite, and Traylor Bros., along with key design firms HDR, Buckland & Taylor, URS, and GZA. TZC is working closely on the project with a team of employees from the New York State Thruway Authority and the State Department of Transportation. It is being designed to achieve a 100-year service life.

The $70-million fabrication contract represents a record for precaster Unistress Corp., says Perri Petricca, president. The panels are straightforward in design, he notes, “but with the requirement of a 100-year design life, they are being manufactured to exacting standards.” Achieving that goal includes such measures as fabricating the panels with high-strength, high-performance concrete and using galvanized-steel reinforcement.

Meeting the tight 18-month schedule, which began in August 2014, required Unistress to invest $6 million in expanding its facility and adding more than 100 employees. The goal is to produce 18 panels per day, with another six to eight months required to complete delivery following casting. The panels will be transported to the Port of Coeymans near Albany, where they will be loaded onto barges and shipped to the job site.

“We are thrilled to have this project as a catalyst for expanding our bridge division and creating new jobs in our community,” says Petricca. “This is a demanding project, both in scale and complexity. The general contractor spent months evaluating proposals from precast producers across the country to make sure that whomever they selected could provide 6,000 pieces on a tight schedule, designed and built to last 100 years.”

The Fort Miller Co. will fabricate precast concrete deck panels for the main span of the bridge. A typical panel of the 973 pieces to be cast measures 14’6” wide and 18’5” to 32’11” long, with a thickness of 10¾ inches.

Each piece also will have 1’4” of rebar protruding from each side, creating panels 17’2” wide that will restrict transportation times and require escorts, according to Joshua French, sales engineer and project manager at Fort Miller. The pieces will be transported on an angle to provide the best maneuverability. The components will be cast and delivered to the site once the construction is ready in 2015.

Project Details

City:

Tarrytown
 

State:

NY
 

Precaster:

(deck panels other than the main span) Unistress Corporation, Pittsfield, MA
(deck panels for the main span) The Fort Miller Co., Inc., Schuylerville, NY
 

Owner:

New York State Thruway Authority and New York State Department of Transportation, Albany, NY
 

Designer/Builder:

Tappan Zee Constructors LLC, including Fluor, American Bridge, Granite and Traylor Bros., along with HDR, Buckland & Taylor, URS and GZA.
 

Total Length:

• 3.1-mile-long twin-span, cable-stayed bridge.
 

Structural Precast Elements:

• 6,000 Precast Concrete Deck Panels (total) designed with a 100-year service life.
Includes:
– 973 road deck panels (main span or in between the towers) fabricated by Fort Miller Group. Typical panel measures 14’6” wide and 18’5” to 32’11” long, with a thickness of 10¾ inches.
– 5,027 deck panels fabricated by Unistress Corporation. Typical panel size will average 12 feet in length, up to 45 feet wide and weigh as much as 74,000 pounds.
 

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