New Tappan Zee Bridge Passes Milestone With Pile Cap Installation
The new Tappan Zee Bridge is finally getting above the waterline, but the $3.9-billion project's finances remain in a state of flux as the U.S. Environmental Protection Agency has rejected a plan pushed by New York Gov. Andrew Cuomo (D) to use state clean-water funds for the project. Despite the funding uncertainty, construction of the new bridge is on schedule.
"Right now, we're about 60% done with pile installation," says Brian Conybeare, special adviser to the governor for the project. The project passed a milestone in late August, with the installation of the first pile caps for the approaches. "The first pile cap is Pier 38, and it's cast in place using a precast pile-cap 'tub.' These tubs have been cast off-site," says Ro DiNardo, general superintendent for Tappan Zee Constructors.
The new bridge consists of two spans, and it will have 43 piers per span, numbered from west to east. The precast pile-cap tubs vary in size, with those on the approaches ranging in width from 30 ft to 40 ft, all the way up to the 300-ft-wide pile caps that will support the new spans' towers. "Basically, the tub acts as a form," says DiNardo. The tubs are floated into place, and the rebar that will form the piers will be incorporated into the pile cap during concrete placement.
"We've had a lot of production this year—in pile-driving, in off-site production of the rebar cages and in casting the precast pile caps," says Tom McGuinness, the New York State Thruway Authority's construction compliance engineer for the new bridge. "Now people will start to see a lot of work appearing above the water line. We're still on schedule."
According to McGuinness, pile work on the new bridge has been split into five headings: the west-shore and east-shore approaches, the main span and two headings on the western causeway. "Work is taking place on all headings right now. We're looking to have pile work substantially complete by the end of the season."
While work on the smaller pile caps near the shore progresses, the project team is getting ready for the main span. "Main-span pile installation has been completed," says McGuinness. "We're in the process of constructing the formwork for the pile caps. The placement of concrete in those pile caps should be complete by the end of the season," he says.
"The critical path is the main span of the bridge," explains McGuinness. "By next spring, we'll have jack forms coming up for the towers, and you'll see them rising. As we move into more substructure work, you'll definitely be seeing more activity above the water."
Funding, Environmental Issues Persist
While the current work on the new Tappan Zee Bridge is funded, the project recently hit a snag in securing further loans. A plan pushed by Gov. Cuomo to use $511 million in loans from the EPA's Clean Water State Revolving Fund for 12 projects related to the new bridge was curtailed by the EPA. The agency ruled that only $29.1 million from the fund can be used on five of the projects. "These are funds that are desperately needed for our water-treatment plants and are not meant to act as a second federal loan for a bridge construction project," says Paul Gallay, president of Riverkeeper, a New York-based clean-water advocacy and watchdog group. The request for the loans had been approved by the New York State Environmental Facilities Corp. (EFC) in June. Following the EPA decision, the New York State Authorities Budget Office announced it was launching a probe into the EFC's approval of the loan request.
The project also ran afoul of permitting issues at one of its off-site staging areas. In late August, Riverkeeper reported to the New York Dept. of Environmental Conservation that construction had begun at the Port of Coeymans, near Albany, before the necessary permits had been issued. The DEC ordered a halt to work until the permits were resolved.
"We want an environmental review for the Coeymans site," says Philip Musegaas, Riverkeeper's Hudson River program director. "They did a full environmental review for the bridge itself, and this site is in a more sensitive area of the river."
