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Third Avenue Bridge (1918-present)
Bridge type:Concrete deck-arch
bridge
Construction of the Third Avenue bridge,
showing falsework, 1917 |
This
2,223-foot-long span was originally called the St. Anthony Falls
Bridge, as it is built over the upper portion of the St. Anthony
Falls Dam. Its alignment follows a shallow reverse S-curve in order
to avoid fractures in the limestone bedrock supporting the bridge
piers; it has the distinction of being the largest concrete arch
bridge on a reverse curve. Much of the design work was done by Minneapolis
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engineer Frederick W. Cappelen,
who was responsible for a number of other local bridges and other structures,
including the Cappelen Memorial (Franklin Avenue) Bridge. Construction
of the $650,000 bridge used techniques which were state-of-the-art for
the time, including the placement of water-tight cofferdams within which
the bridge piers were poured. The concrete arches were formed against
“falsework,” which supported and shaped the arches and then
were removed after completion. A number of modifications have been made
to the bridge over the years, including a major renovation in 1979- 80.
See
more images of the Third Avenue Bridge
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| Construction of Third Avenue
bridge, showing arches after falsework has been removed, 1917
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Third Avenue bridge viewed from west bank; Exposition Building (1887-1940)
prominently visible on the east bank, ca. 1923 |
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