Accelerated Construction Technology Transfer
|FHWA > Engineering > Construction > Quality > ACTT > State Workshop Reports > New York > Chapter 2|
ACTT Workshop: New York
|2||Used to shade between a rating of 1 and 3.|
|3||Seriously deteriorating, or not functioning as originally designed.|
|4||Used to shade between a rating of 3 and 5.|
|5||Showing minor deterioration; is functioning as originally designed.|
|6||Used to shade between a rating of 5 and 7.|
|7||Exhibiting like-new condition.|
|West Causeway Deck (spans 1-166)||3.0|
|West Truss Deck (spans 167-172)||2.6|
|Main Span Deck (spans 173-178)||3.0|
Ground penetrating radar (GPR) and underdeck soundings performed in 2002 indicate that approximately 475,000 square feet of the 1,075,000 square feet (spans 1 through 178) have been denoted as deficient, which means they show imminent spalling or are hollow sounding. Additionally, a minimum of 960 potential punch throughs have been identified, with 46 percent located in the outboard lanes, lanes one and seven, and the next highest level of potential failures, 26 percent, located in lanes two and six.
The Thruway Authority's maintenance records show that crews repaired 29 punch throughs in 2002, 55 in 2003 and 66 in 2004. Each repair averaged approximately nine square feet in size and took anywhere from four to eight hours to complete, significantly reducing the level of service provided during each repair.
The concrete walkway and structural steel exhibit significant deterioration as well. The 2002 inspection report rated the existing concrete walkway a two, stating that the section is in a "serious state of deterioration," with approximately 80 percent of the concrete walkway in need of repair.
Likewise, the degree of deterioration on 63 percent of the cantilevered steel is considered severe, with significant section loss in the exterior bays occurring because of deck runoff from the open drainage system. This type of drainage system allows water containing chlorides from deicers to flow from the roadway surface down onto the structural steel. The existing roadway lighting and associated wiring components located on the cantilevered section have undergone regular maintenance due to deterioration of the electrical system consistent with the issues noted above.
The State of New York is conducting an environmental study for the entire I-87/I-287 corridor. Pending the results of that study, the Thruway Authority has an urgent need to address existing bridge deficiencies on the Tappan Zee. In order to do that, the Thruway Authority has noted the following objectives:
The Thruway Authority is also seeking to employ the philosophy of the FHWA Highways for LIFE (Long lasting highways using Innovative technologies and practices to accomplish Fast construction of Efficient and safe pavements and bridges) initiative. The FHWA initiative targets certain goals:
Further, the Thruway Authority is looking to utilize nighttime construction to minimize user delays. By utilizing the work zone technology noted above, the Thruway Authority plans to keep traffic impacts at a minimum during the nighttime construction window.
Other project goals are as follows:
Prior to the start of the workshop, the Tappan Zee Bridge Repair Project Team had identified what it felt was the only realistic alternative for meeting the goals described above: remove the existing bridge superstructure (deck and steel girders), along with the cantilevered fascia section, from spans 1 through 178 and install a new superstructure.
The new structure would consist of a prefabricated superstructure system with upgraded roadway lighting, associated electrical work, bridge railing system, drainage system and associated substructure modifications. As detailed, the work would be let in three successive construction contracts.
Remove the existing deck and support steel in lanes one, two, six and seven and the cantilevered walkway from spans 1 through 178. Install the prefabricated superstructure system. Replace the bridge rail and roadway lighting. Perform substructure repairs in affected areas.
Remove the existing deck and support steel in lanes three through five from spans 167 through 178. Install the prefabricated superstructure system. Perform substructure repairs in affected areas.
Remove the existing deck and support steel in lanes three through five from spans 81 through 166. Install the prefabricated superstructure system. In lanes through five, remove the remaining original superstructure up to the prefabricated median superstructure (contract TANY 96-1B) from spans 1 through 81. Perform substructure repairs in affected areas.
The estimated project timeframes are as follows:
This project is scheduled to be let in 2005, with construction scheduled to take place from 2006 through 2008. The project will be funded completely with Thruway funds.
This project is scheduled to be let in 2008, with construction slated to occur in 2009 and 2010. Funding sources are still to be determined.
This project is scheduled to be let in 2010, with construction tentatively scheduled for 2011 and 2012. Funding sources are yet to be determined.
|<< Previous||Contents||Next >>|