The Plymouth Avenue Bridge is a

segmental bridge A segmental bridge is a bridge built in short sections (called segments), i.e., one piece at a time, as opposed to traditional methods that build a bridge in very large sections. The bridge is made of concrete that is either cast-in-place (constru ...

that spans the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it f ...

Minneapolis Minneapolis () is the largest city in Minnesota, United States, and the county seat of Hennepin County. The city is abundant in water, with thirteen lakes, wetlands, the Mississippi River, creeks and waterfalls. Minneapolis has its origins ...

. It was built in 1983 and was designed by Van Doren-Hazard-Stallings. The construction of this bridge was unique, for it was the first segmental concrete girder bridge built in

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

. This method of design uses a "form traveler" that shapes the concrete as it is built out from the piers. This avoided the use of

falsework Falsework consists of temporary structures used in construction to support a permanent structure until its construction is sufficiently advanced to support itself. For arches, this is specifically called centering. Falsework includes temporary su ...

and avoided impeding river traffic. The concrete is also engineered to be salt-resistant by the use of post-tensioning. Tubes run through the concrete structure carrying strands of cable. With tension on the cables, the structure is designed to be under compression. This prevents cracks and hinders the intrusion of salt water. Since then, other bridges in Minnesota have used this construction method, including the

I-35W Saint Anthony Falls Bridge The I-35W Saint Anthony Falls Bridge crosses the Mississippi River one-half mile (875 m) downstream from the Saint Anthony Falls in Minneapolis, Minnesota in the U.S., carrying north–south traffic on Interstate Highway 35W. The ten-lane br ...

in Minneapolis, the Wabasha Street Bridge in downtown

St. Paul Paul; grc, Παῦλος, translit=Paulos; cop, ⲡⲁⲩⲗⲟⲥ; hbo, פאולוס השליח (previously called Saul of Tarsus;; ar, بولس الطرسوسي; grc, Σαῦλος Ταρσεύς, Saũlos Tarseús; tr, Tarsuslu Pavlus; ...

, and the

Wakota Bridge The Wakota Bridge is a ten-lane bridge carrying Interstate 494 over the Mississippi River between South St. Paul and Newport, Minnesota, United States. It was completed in 2010, replacing a four-lane span built in 1959. The name was given to the ...

South St. Paul South St. Paul is a city in Dakota County, Minnesota, Dakota County, Minnesota, United States, located immediately south and southeast of Saint Paul, Minnesota, St. Paul. It is also east of West St. Paul, Minnesota, West St. Paul. The population ...

. The original bridge at this location was a wooden

Howe truss A Howe truss is a truss bridge consisting of chords, verticals, and diagonals whose vertical members are in tension and whose diagonal members are in compression. The Howe truss was invented by William Howe in 1840, and was widely used as a bridg ...

design, built in 1873. It was built when Minneapolis, then only on the west side of the river, consolidated with the city of St. Anthony, on the east side of the river. As part of the merger, Minneapolis agreed to build two bridges, one upstream of the

Hennepin Avenue Bridge The Hennepin Avenue Bridge is the structure that carries Hennepin County State Aid Highway 52, Hennepin Avenue, across the Mississippi River in Minneapolis, Minnesota, at Nicollet Island. Officially, it is the Father Louis Hennepin Bridge, in hon ...

and one downstream. That bridge was replaced in 1886 with an iron

truss bridge A truss bridge is a bridge whose load-bearing superstructure is composed of a truss, a structure of connected elements, usually forming triangular units. The connected elements (typically straight) may be stressed from tension, compression, or ...

. It was remodeled in 1913 and then raised in 1953 for more clearance. The bridge was closed in 1981 because the floor beams were deteriorated by corrosion over the years. The current bridge was constructed two years later. On Friday, October 22, 2010, the Plymouth Avenue Bridge was closed indefinitely "as a precaution, pending further investigation after a routine inspection discovered corrosion on cables that run through the bridge." The bridge was reopened to foot traffic on Thursday, January 6, 2011, after engineers determined that the bridge was safe for pedestrian and bicycle use. Use by vehicular traffic was not allowed until corroded cables could be replaced, a project that, following several delays, was completed as of August 9, 2013.

References

* * {{Crossings navbox , structure = Crossings , place =

, bridge = Plymouth Avenue Bridge , bridge signs = , upstream = Broadway Avenue Bridge , upstream signs = , downstream =

Minneapolis BNSF Rail Bridge Minneapolis BNSF Rail Bridge is a combination plate girder bridge and truss bridge that spans the main channel of the Mississippi River between downtown Minneapolis, Minnesota and Nicollet Island in Minneapolis. It is located adjacent to the cu ...

(West channel)
Wisconsin Central Boom Island Rail Bridge (East channel) , downstream signs = Bridges in Minneapolis Bridges over the Mississippi River Bridges completed in 1983 Concrete bridges in the United States Girder bridges in the United States Road bridges in Minnesota Shared-use paths in Minneapolis