A Virtual Introduction to Segmental Concrete Bridge Technology
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: benjamin.tang@fhwa.dot.gov).
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
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Articles in this issue:
Safety, Security, Reliability, and Efficiency: Working Together for Better Bridges and Tunnels
A Virtual Introduction to Segmental Concrete Bridge Technology
The Concrete of the Future
Your Guide to Transportation Asset Management
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