Hiawatha Avenue and Downtown Minneapolis

The Martin Olav Sabo Bridge is a

bridge A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somethi ...

in the city of

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 ...

and the first

cable-stayed suspension bridge A cable-stayed suspension bridge or CSS bridge merges the designs of cable-stayed bridges and suspension bridges. The suspension bridge's architecture is better at handling the load in the middle of the bridge, while the cable stayed bridge is be ...

in the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sover ...

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 ...

. Formerly the Midtown Greenway Pedestrian Bridge, it was renamed in honor of former

Representative Representative may refer to: Politics *Representative democracy, type of democracy in which elected officials represent a group of people *House of Representatives, legislative body in various countries or sub-national entities *Legislator, someon ...

Martin Olav Sabo Martin Olav Sabo (February 28, 1938 – March 13, 2016) was an American politician who served as United States Representative for , which includes Minneapolis; the district is one of eight congressional districts in Minnesota. Early life and e ...

, a fourteen-term member of Congress from Minnesota. Opened and dedicated in November 2007, the bridge crosses

Hiawatha Avenue Minnesota State Highway 55 (MN 55) is a highway in west-central, central, and east-central Minnesota, which runs from the North Dakota state line near Tenney and continues east and southeast to its eastern terminus at its intersection with U.S. Hi ...

(Trunk Highway 55) north of 28th Street East and just south of 26th Street East, joining Phase 2 and Phase 3 of the Minneapolis

Midtown Greenway The Midtown Greenway is a rail trail in Minneapolis, Minnesota that follows the path of an abandoned route of the Milwaukee Road railway. It is considered under segregated cycle facilities. Used both recreationally and for commuting, the p ...

at Hiawatha Avenue, allowing a continuous

biking Cycling, also, when on a two-wheeled bicycle, called bicycling or biking, is the use of cycles for transport, recreation, exercise or sport. People engaged in cycling are referred to as "cyclists", "bicyclists", or "bikers". Apart from two ...

connection across the city. The bridge also links Longfellow community (

Longfellow Henry Wadsworth Longfellow (February 27, 1807 – March 24, 1882) was an American poet and educator. His original works include "Paul Revere's Ride", ''The Song of Hiawatha'', and ''Evangeline''. He was the first American to completely transl ...

and Seward neighborhoods) to Phillips community ( East Phillips neighborhood), and connects users to the north-south

Hiawatha LRT Trail Hiawatha LRT Trail is a , multi-use path adjacent to a light-rail transit line in Minneapolis, Minnesota, United States, that is popular with bicycle commuters. Users travel along the Metro Blue Line and Hiawatha Avenue transit corridor, reac ...

and

Little Earth Trail Little Earth Trail is an approximately , multi-use bicycle path in Minneapolis, Minnesota, United States, that links several neighborhoods, parks, businesses, and trails in the Phillips community. The trail begins at its northern end near the i ...

. The bridge was built by Hennepin County and transferred to the City of Minneapolis, which owns and maintains the bridge. The bridge was closed on February 20, 2012 when two of the cables that support the bridge fell due to cracks in their attachment points; additional significant cracks were subsequently found in two other support plates. The bridge, supported with temporary bracing, was reopened June 1, 2012. A summary report of the failure analysis released June 8, 2012 determined that unaccounted for wind-induced cable vibrations led to the failures of the attachment points. The bridge was again closed for repairs on September 23, 2012. Repairs were completed, and the bridge reopened, on November 19, 2012.

Configuration

The new bridge eliminates the need for

bicyclists Cycling, also, when on a two-wheeled bicycle, called bicycling or biking, is the use of cycles for transport, recreation, exercise or sport. People engaged in cycling are referred to as "cyclists", "bicyclists", or "bikers". Apart from two- ...

and

pedestrians A pedestrian is a person traveling on foot, whether walking or running. In modern times, the term usually refers to someone walking on a road or Road surface, pavement, but this was not the case historically. The meaning of pedestrian is dis ...

to cross busy Hiawatha Avenue with a

stoplight Traffic lights, traffic signals, or stoplights – known also as robots in South Africa are signalling devices positioned at road intersections, pedestrian crossings, and other locations in order to control flows of traffic. Traffic lights ...

at grade-level. Instead, the bridge brings them north one block, over the highway, and back south, introducing a new grade-level crossing of 28th Street East west of Hiawatha. Users are still able to use the at-grade Hiawatha crossing after completion.

Structure

The bridge has a total length of 2,200 feet. Its main span passes 220 feet over Hiawatha Avenue, with the cable-stay tower rising 100 feet above the bridge-deck level. The Martin Olav Sabo Bridge is the first true cable-stayed suspension bridge in the State of Minnesota. Its design was the product of engineering consulting firm

URS Urs (from ''‘Urs'') or ''Urus'' (literal meaning wedding), is the death anniversary of a Sufi saint, usually held at the saint's dargah (shrine or tomb). In most Sufi orders such as Naqshbandiyyah, Suhrawardiyya, Chishtiyya, Qadiriyya, etc. t ...

, with community input.

History

During Congressman Martin Olav Sabo's tenure, he earmarked $2.9 million in federal funding to the project. He is also recognized for acquiring federal funding to complete many capital improvements throughout Minneapolis. City advisory boards and committees forwarded the recommendation to rename the bridge after Sabo in 2005, which was done by the City Council.

Hennepin County Hennepin County ( ) is a county in the U.S. state of Minnesota. Its county seat is Minneapolis, the state's most populous city. The county is named in honor of the 17th-century explorer Father Louis Hennepin. The county extends from Minneapol ...

provided additional funding to total $5.1 million for the final project.

2012 structural failures

Late on the night of February 19, 2012, the two longest support cables on the bridge were found detached and lying across the bridge deck below. The bridge was closed shortly thereafter to all traffic. The portion of Hiawatha Avenue that passes underneath the bridge was also closed, and light rail service was suspended on the tracks that pass beneath the bridge. The light rail resumed service on February 24, 2012, after emergency supports were placed underneath the bridge and a second pair of cables were removed due to cracks in their anchor points. Hiawatha Avenue was reopened to traffic underneath the bridge on February 27, 2012. The original cable failure was due to cracks in diaphragm plates that anchor the ends of the cables to the steel tower, and significant cracks have subsequently been found in three of those anchorages. The engineering firm

Wiss, Janney, Elstner Associates, Inc. Wiss, Janney, Elstner Associates, Inc. (WJE) is an American corporation of architects, engineers, and materials scientists specializing in the investigation, analysis, testing, and design of repairs for historic and contemporary buildings and stru ...

was hired to investigate how the diaphragm plates became compromised. On June 8, 2012, a summary report of the investigation was released in which the failure was attributed to wind-induced "cable vibrations that induce damaging stress range cycles at fatigue sensitive details in the cable diaphragm plates." The effect of cable vibrations caused by wind was not included in the original design package for the bridge. The bridge reopened for bicycle and pedestrian traffic on June 1, 2012, with temporary support structures in place. New plates were designed, and the bridge was closed once more between September 23, 2012, and November 19, 2012, to allow them to be retrofitted as permanent repairs.

References

External links

* This contains official City Council approval on the bridge. *{{cite web , url=http://www.ci.minneapolis.mn.us/cip/mg_pedbridge/ , publisher=City of

, title= Capital Improvement Projects: Midtown Greenway Pedestrian Bridge , access-date=August 31, 2007 , year=2007 This contains the City of Minneapolis published update of the project.
North American Cable-Stayed Bridge RegistryMetal Geek blog on the bridge construction
Pedestrian bridges in Minnesota Cable-stayed bridges in the United States Bridges in Minneapolis Bridges completed in 2007 Steel bridges in the United States Shared-use paths in Minneapolis