East-coast feel
In New England, four precast companies participated in development of NEXT Beam standards, including Dailey Precast, the producer of the first beams. Each of the NEXT Beam projects let so far has had multiple bidders. With such fabricator interest, pricing will be competitive. Initial cost comparisons demonstrate that NEXT Beams are very competitive with other bridge systems. In some cases, superstructure cost savings can be as much as 30%, depending upon span length.
Bridge owners are greeting the arrival of the NEXT Beam with considerable enthusiasm. They appreciate the improved durability, competitive cost and design flexibility of the NEXT Beam. Already, the New York State DOT (NYSDOT) and Maine DOT have let projects using the NEXT Beam. All other New England states are open to its use, and in the Mid-Atlantic, owners also have shown interest. Of note, the Pennsylvania Department of Transportation (PennDOT) published a standard drawing in March 2010 for the F Beam (modified to reflect PennDOT design practices), and the New Jersey DOT (NJDOT) has expressed interest in the D Beam for rapid bridge replacement. Foremost, the NEXT Beam is envisioned as a stringer (i.e., a beam system parallel to traffic), as demonstrated in the first NEXT Beam project in Maine. The project includes two NEXT Beam bridges, the New Bridge over York River and the Station 44 bridge. Designed by Vanasse Hangen Brustlin Inc., the New Bridge will have two 55-ft and five 80-ft F Beam spans, all continuous. Note that on this project the NEXT Beam structure was the low-cost alternative in comparison with Northeast bulb tees. Both of these structure types were designed and permitted in Maine DOT’s contract documents.
The versatile NEXT Beam also can be readily used transverse or skewed to the supported roadway, as in the case of the Queens Boulevard Bridge over Van Wyck Expressway that was let by the NYSDOT in February this year. Designed by Hardesty & Hanover LLP of New York, this project features a very wide, sharply skewed bridge over the wide, heavily used Van Wyck Expressway. The Queens Boulevard bridge supports will be three walls that run parallel to the expressway below—two abutment walls at the expressway edges and one multicolumn center pier in the median. The NEXT Beams bear upon these walls, spanning transversely across the expressway and skewed with respect to Queens Boulevard. Both simple-span and two-span continuous beams are utilized, designed to act as a simple span under dead load and continuous under live load. The High Bridge Team of Lancaster, Pa. (High Steel Structures Inc. and High Concrete Group LLC) has been chosen by the contractor, ECCO III Enterprises, to supply the NEXT Beams for this project pending contract award by the state of New York.
According to NYSDOT Regional Structures Engineer Harold Fink, P.E., the NEXT Beam was chosen because of lower costs than comparable structure types and superior ability to accommodate utilities.
“The Queens Boulevard over the Van Wyck Expressway carries many utilities, and the NEXT Beam provides flexibility to support utilities in any bay,” commented Fink. “The soffit eliminates the need for deck forms, and the shape is fully accessible for inspection access as opposed to a box beam. Because of these reasons, the NEXT beam is one of the top choices for spans up to about 80 ft—LRFD strength II loading.”
“This efficient option will require minimal or no temporary shoring, resulting in lower construction costs,” added David Tuckman, P.E., principal associate for Hardesty & Hanover. “This option creates a highly redundant system. If a section of the NEXT Beam is damaged, its load path will be redistributed amongst the adjacent tee beams and will not result in structure failure.”
The NEXT Beam also was considered as an alternative solution for the NJDOT’s Rte. 52 causeway bridge. A value-engineering study showed that the NEXT Beams were suitable and 30% more cost competitive than the designed superstructure; however, they were not utilized because of the additional time and cost associated with the redesign. This again indicates, however, that in design-build projects and future design-bid-build projects, the NEXT Beam will provide a cost-effective alternative for bridges with spans less than 90 ft.