A High-Performance Steel Scorecard
From Oregon to New York State, construction of high-performance steel
(HPS) bridges is on the rise. Since the first HPS bridge in the United
States opened to traffic in December 1997 in Snyder, Nebraska, HPS has
been used in more than 150 bridges nationwide. This figure includes
bridges currently in the design or fabrication stages, as well as those
that have already opened. Developed through a joint effort among the
Federal Highway Administration (FHWA), American Iron and Steel Institute
(AISI), and the U.S. Department of the Navy, HPS (which includes grades
HPS-70W and HPS-50W) is stronger and has less than 60 percent of the
carbon and about 15 percent of the sulfur of conventional steel. HPS
is also tougher than conventional steel and can offer greater resistance
to cracking compared with conventional bridge steels.
 |
| This simple-span structure over the Berkshir Thruway in New
York State was constructed using HPS-70W. |
The New York State Thruway Authority has used HPS-70W on a number of
bridges, including a simple-span structure over the Berkshire Thruway
and many two-span continuous structures, such as one at the I-90, Exit
54 interchange. The use of HPS-70W on the Berkshire Thruway bridge eliminated
the need for an interior pier to support the superstructure between
abutments. On the I-90 interchange, all components of the bridge's primary
stress-carrying members were fabricated using HPS-70W, including stiffeners
and connection plates. The Thruway Authority has found HPS-70W to be
an excellent alternative to conventional steels. "Overall we've
been very pleased with the performance. We like the increased toughness
and weathering characteristics of the steel," says Peter Stapf
of the Thruway Authority. The 40 percent higher yield strength of the
HPS allows engineers to design longer, shallower spans, which has provided
increased vertical clearance underneath the existing structures without
substantial modification of the structure profile and approaches. "We
consider HPS to be another tool in our box now. We have a couple of
bridges currently under construction and will construct a 269-ft simple
span structure later this season," says Stapf.
 |
States with HPS bridges.
The first number indicates bridges that are in service, the second
lists those in fabrication or construction, and the third number
indicates bridges in planning or design. |
The HPS Steering Committee, which includes representatives from FHWA,
the U.S. Navy, AISI, and the National Steel Bridge Alliance, recommends
that fabrication of HPS be done using the provisions of the Guide Specifications
for Highway Bridge Fabrication with HPS 70W Steel (Publication Code
HBF-1). This document, published by the American Association of State
Highway and Transportation Officials (AASHTO), is available from the
AASHTO Publications Order Department, 800-231-3475 (Web: www.transportation.org/publications/bookstore.nsf).
An HPS Designer's Guide was also released by FHWA last year, providing
details on using HPS for bridges as well as contacts for more information.
The guide will soon be on the Web at www.fhwa.dot.gov/bridge.
From the main page, go to the "high-performance steel" link.
HPS will also be the subject of an upcoming conference, "2002 FHWA
Steel Bridge Conference for the Western United States." To be held
December 12-13, 2002, in Salt Lake City, Utah, the conference will focus
on design, fabrication, construction, and research issues related to
steel bridges. For more information on the conference, contact Dr. Atorod
Azizinamini at the National Bridge Research Organization, 402-472-3462
(fax: 402-472-6658; email: nabro@unlnotes.unl.edu).
The map (above), which was developed by the HPS
Steering Committee, shows the status of HPS bridge building and design
across the country. To learn more about completed and planned HPS projects,
visit the HPS Scoreboard at www.steel.org/infrastructure/sbf/hps_scoreboard_
1100.xls.
For more information, contact Krishna Verma, Senior Welding Engineer
in the Office of Bridge Technology at FHWA, 202-366-4601 (fax: 202-366-3077;
email: krishna.verma@fhwa.dot.gov).
For more information on the bridges built by the New York State Thruway
Authority, contact Peter Stapf at 518-471-4255 (email: peter_stapf@thruway.state.ny.us).
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Articles in this issue:
RAP and Superpave: An Excellent Blend
Now is the Time for Work Zone Safety
A High-Performance Steel Scorecard
Professor Training Workshop Showcases DataPave
3.0
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