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The Chesapeake & Delaware (C&D) Canal Bridge is the first major concrete
cable-staved bridge structure to be completed in the Northeast. The $58 million bridge is
a 4,650' structure providing six lanes of travel with three 12' lanes and two 10'
shoulders in each direction of travel. The use of a single plane of cable stays to support
the 750' main span creates all aesthetically pleasing and graceful appearance to the
surrounding landscape. 
Structural elements were created both
off and on-site for the C&D bridge. Two noteworthy pieces of the structure were
responsible for creating much of the $6.2 million savings in cost and time over the
alternate steel design. Approximately 590 box girders each containing 6,000 pounds of
reinforcing-bars and 24 cubic yards of concrete were created at a site 180 miles south of
the project and transported by barge to the site. 72 delta frames, weighing 50 tons each
and containing more than 7,600 pounds of reinforcing bars accomplished several purposes:
they combined the box girders, making the span into a single bridge; acted as part of the
cable stay system; and allowed a single cross-section to be used for both the approach and
main span.
The pylons which anchor the cable stays
were cast-in-place using externally reinforced forms to create 10' lifts. A tower crane
advanced the forms, installed the pre-tied reinforcement cage and placed concrete. Each
pylon footing used over 72,000 pounds of bar reinforcement and 730 cubic yards of'
concrete. Each pylon supports 17 cable stays and extends 322' from the ground level to
their top.
Innovative construction techniques,
economy, and aesthetics were the primary focus of the construction and design solutions
used for this elegant structure. Ali overhead erection truss and twin 200 ton crawler
cranes allowed the bridge to be built from above, minimizing disruption to the traveling
public and navigation traffic, and easing construction. The use of' steel reinforced
concrete elements provided an efficient and time saving technique for the construction of
this bridge. |
