U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-HRT-04-021
Date: December 2003
Is a segmental concrete bridge right for you? When should highway agencies consider this technology as an economical choice for their bridge construction projects? The Federal Highway Administration's (FHWA) new Segmental Concrete Bridge Technology "virtual" team aims to raise awareness of the technology's unique strengths, as well as its limitations, and to "promote the exchange of best practice insights among government institutions and private industry," says M. Myint Lwin, team co-leader and Director of the Office of Bridge Technology at FHWA.
Team members represent FHWA, State departments of transportation, and industry. Members bring to the table expertise on "project inception, structure concept evaluations, design and construction, and maintenance," notes team member Jerry Potter, Major Bridge Projects Engineer at FHWA. "The team is also working to add members experienced in construction and construction oversight and management," adds Potter.
Segmental concrete bridge technology (SCBT) describes a method of joining numerous cast-in-place or precast bridge elements to form a continuous span. The technique was first used in Europe in the 1950s and began to catch the attention of U.S. designers in the early 1970s. It is now an increasingly popular solution to the engineering challenges posed by deep valley crossings and those in sensitive environments or over wide spans of water. Segmental construction is also useful when interchange ramps (both tangent and curved types) and bypasses must be erected across existing roadways and when performing smaller-scale projects in tight urban spaces without interrupting traffic.
"The key objectives of the team are to accelerate the development of technical expertise and leadership, create innovative and efficient ways to advance technologies, establish a community of practice, and share knowledge and information to improve and advance the segmental concrete bridge technology," says Benjamin Tang, Team Leader in FHWA's Office of Bridge Technology and co-leader of the virtual team.
While there is much accumulated experience on how to address specific engineering and construction challenges that arise in segmental concrete bridge projects, the data have not always been well organized and catalogued for efficient access by bridge designers. To facilitate the dissemination of knowledge within the engineering community and to promote best practices, the virtual team has launched a Web site at www.fhwa.dot.gov/bridge/segmental/.
Topics addressed on the Web site to date range from engineering issues, such as the cumulative effects of day-to-day temperature fluctuations on a bridge's structural integrity, to guidance on identifying conditions where segmental concrete structures prove to be more economical than other bridge types. Construction methods are also covered.
The site features a reference library, photo gallery highlighting significant SCBT projects, calendar of upcoming events, and an archive of questions that have been submitted by site users and answered by team members. This "Ask the Experts" feature reflects participation by a range of site visitors, from industry professionals to engineering students.
To learn more about SCBT or the virtual team, visit www.fhwa.dot.gov/bridge/segmental, submit a question to the site's "Ask the Expert" section, or contact Benjamin Tang at FHWA (email: firstname.lastname@example.org).
FHWA's Office of Bridge Technology has embraced the concept and value of virtual teams, as it recognizes that there is a wealth of bridge engineering knowledge and expertise available from practicing professionals, industry, and academia that can be used to augment FHWA's in-house expertise. Several virtual teams have therefore been created to provide technical assistance and act as a focal point and clearinghouse on current and forthcoming initiatives, information, and technical materials. Virtual team members contribute their time and efforts on a voluntary basis.
Other structural virtual teams that have been established to date include ones for high-performance steel, seismic engineering, high-performance concrete (see September 2003 Focus), tunnels, high strength bolts, and fiber-reinforced polymers. To learn more, visit the following Web sites. Additional virtual teams are in the works, including those for cable-stay bridges, load and resistance factor design, accelerated bridge construction, and bridge monitoring.
Fiber-Reinforced Polymer Composites- www.fhwa.dot.gov/bridge/frp/index.cfm
High-Performance Steel- www.fhwa.dot.gov/bridge/hps.htm
High Strength Bolts- www.fhwa.dot.gov/bridge/bolts.htm
Seismic Technology- www.fhwa.dot.gov/bridge/seismic/index.htm
Road Tunnels- www.fhwa.dot.gov/bridge/tunnel/index.htm
High-Performance Concrete- knowledge.fhwa.dot.gov/cops/hpcx.nsf/home