Stone abutments hide short, counterweighted side spans of the attractive, three span continuous structure.
Exodermic Deck Erected in Dramatic Scenery of Niagara Falls
Two bridges connect Goat Island at the American Falls in Niagara Falls, NY to the mainland. One carries primarily pedestrian traffic and light park agency vehicles. The other carries most of the truck and passenger vehicle traffic to the island. Because Goat Island is a heavily visited tourist site in the summer, Park officials and the New York State Department of Transportation worked hard to plan rehabilitation of the main roadway bridge so that it would be open to traffic through the summer, with the bulk of the construction work taking place during two off-seasons, from labor Day through Memorial Day. The Buffalo area is renowned for its winter weather, and the winter of 2001/2002 was no exception. Over seven feet (2.1 meters) of snow fell in one storm in the region, though at the Goat Island Bridge,“only” two feet (610 mm) of snow fell. But con- tractor A&L was back at work as soon as the snow was cleared.
The bridge is in a dramatic setting, just a few hundred feet (200 meters) from the edge of the Falls, and turbulent
white water runs under the bridge. Safety was, of course, a primary concern.
The Goat Island Bridge is a very inter- esting structure. It appears to be a shal- low arch, but in fact, is a three span con- tinuous structure with short, counter- weighted side spans hidden in what appear to be deep stone abutments. The cast-in-place Exodermic deck was select- ed in order to save weight on the main center span, thus increasing the live load capacity of the bridge. Cantilevered side- walks were also specified as Exodermic decks, both for weight savings and for their structural efficiency, which allowed the supporting steel members to be spaced fairly widely apart.
Although the main girders are 11 feet (3.4 meters) apart, site considerations allowed the use of a deeper and hence more efficient deck design. Main bars of the Exodermic deck are WT6x7’s at 12 inch centers (WT152x10.4 at 305 mm), with the top inch (25 mm) of the T’s made composite with a 4.5” (114 mm) concrete slab, giving a total deck thick- ness of 9.5” (241 mm). The efficiency of
the design was reflected in the deck price, which was bid at $28 per square foot ($301 per square meter) in-place, including steel grid, reinforcing, fabricat- ed scuppers, concrete, and erection.
All deck and sidewalk panels were in place by the end of February, and the concrete pours were made in early spring, as soon as weather permitted. Work was completed in one season rather than the two assumed in the con- tract plans developed in-house by the New York State DOT. Contractor A&L, Inc. and Exodermic deck licensee American Bridge Manufacturing were justifiably proud when Governor George Pataki cut the ribbon on May 15 to reopen the bridge.
With the sidewalk located lower than the road- way deck, it was erected first.
EXODERMIC BRIDGE DECK, INC. • 60 LONG POND RD, LAKEVILLE, CT 06039 • TEL: 860.435.0300 • FAX: 860.435.4868 • email@example.com