Bridge construction in the Puget Sound region and other metropolitan areas can
severely exacerbate traffic congestion, resulting in costly delays to motorists
and freight. Bridge types that can be constructed and/or reconstructed rapidly
are needed to reduce these delays. The use of precast concrete components in
bridges presents a potential solution, because the components can be fabricated
off-site in advance of construction, reducing the amount of time required to
complete the bridge and the number of construction tasks that must be completed
on-site.
Precast, prestressed concrete girders
are currently used widely; however, the use of precast components for other
portions of a bridge has been limited. Precast components for bridge
substructures have been used mainly in non-seismic regions because difficulties
creating moment connections between precast components have hindered their use
in seismic regions.
Two precast concrete bridge pier
systems developed for use in the seismically active portion of Washington State are presented in this report. In
order to use these systems, design procedures are required to ensure that the
precast pier systems will exhibit acceptable performance in earthquakes and not
experience excessive damage. This report focuses on the development and
evaluation of these design procedures.
Disruption of highway traffic flow
due to bridge construction is becoming less tolerable as the amount of
congestion in metropolitan areas increases. The direct costs (traffic control,
barricades, etc.) and indirect costs (delays to motorists) from partial or full
closure of a roadway to accommodate bridge construction can be staggering. A
recent study in Houston
found that the indirect costs associated with closing a highway bridge near the
city center were over $100,000 a day (Jones and Vogel 2001). Bridge designs
that can be constructed rapidly are needed to reduce these costs and better
serve motorists.
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