The Main Street Bridge in

Columbus Columbus is a Latinized version of the Italian surname "''Colombo''". It most commonly refers to: * Christopher Columbus (1451-1506), the Italian explorer * Columbus, Ohio, capital of the U.S. state of Ohio Columbus may also refer to: Places ...

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

is a , three-span, inclined

tied arch bridge A tied-arch bridge is an arch bridge in which the outward horizontal forces of the arch(es) caused by tension at the arch ends to a foundation are countered by equal tension of its own gravity plus any element of the total deck structure such grea ...

over the

Scioto River The Scioto River ( ) is a river in central and southern Ohio more than in length. It rises in Hardin County just north of Roundhead, Ohio, flows through Columbus, Ohio, where it collects its largest tributary, the Olentangy River, and meets t ...

. The bridge is the first in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

and the fifth in the world to use an inclined single-rib-tied arch superstructure. The final cost for the bridge was $60.1 million. It carries Main Street (

U.S. Route 62 U.S. Route 62 or U.S. Highway 62 (US 62) runs from the Mexican border at El Paso, Texas, to Niagara Falls, New York, near the Canadian border. It is the only east-west United States Numbered Highway that connects Mexico and Can ...

and

Ohio State Route 3 State Route 3 (SR 3) is a major north–south (physically northeast-southwest) highway in Ohio which leads from Cincinnati to Cleveland by way of Columbus. It is the second longest state route in Ohio. Because of this, the road is also known ...

) northwest from Downtown Columbus into Franklinton, splitting into Rich and Starling Streets just west of the bridge.

History

The original Main Street bridge was a Whipple through truss bridge built in 1890 over the Scioto River. It was lengthened in 1917 using two spans salvaged from a railroad bridge a short distance downstream of the bridge. In the 1930s, it was replaced with a multiple-span,

art-deco Art Deco, short for the French ''Arts Décoratifs'', and sometimes just called Deco, is a style of visual arts, architecture, and product design, that first appeared in France in the 1910s (just before World War I), and flourished in the United ...

open-spandrel concrete deck arch bridge, built in 1937. After years of degradation due to weather and traffic, the bridge was deemed unfit for use and closed in 2002. The 1937 bridge was part of the

Scioto River Bridge Group The Scioto River Bridge Group was a set of historic bridges in Columbus, Ohio. The bridges were: *The Broad Street Bridge, replaced by the Discovery Bridge *The Main Street Bridge (1937-2002), replaced by the Main Street Bridge (2010-present) ...

, listed on the Columbus Register of Historic Properties in 1983 and proposed as part of the

Columbus Civic Center Historic District The Columbus Civic Center is a civic center, a collection of government buildings, museums, and open park space in Downtown Columbus, Ohio. The site is located along the Scioto Mile recreation area and historically was directly on the banks of th ...

, nominated to the National Register of Historic Places in 1988. Wanting an iconic structure to replace the old bridge, the city of Columbus contracted Dr. Spiro Pollalis, professor of design technology and management at the

Harvard University Graduate School of Design The Harvard Graduate School of Design (GSD) is the graduate school of design at Harvard University, a private research university in Cambridge, Massachusetts. It offers master's and doctoral programs in architecture, landscape architecture, urban ...

to design the bridge. His design, altered slightly for budget reasons, opened for traffic on July 30, 2010. When the former bridge closed, engineers estimated that a replacement would cost approximately $19.5 million. However, by 2004, estimates climbed $29.5 million. When planners received construction bids in 2006, the lowest was $44.1 million. Cost overruns, design changes and inspections added another $10 million to the structure's final cost.

Design

Arch

The original concept of the Main Street bridge was far more complex and costly than the final design. Initially, the bridge called for a very shallow 10:1 span-to-rise ratio for the main arch, creating significant axial and bending forces. To accommodate the excess forces, the design called for expensive, high-strength concrete and steel to support the bridge. Because of the high cost of materials and construction of such a span, the design of the arch was revised to a 6.6:1 span-to-rise ratio, making the main arch taller and decreasing its length from to . This design change was expected to allow for cheaper materials and save over of steel while keeping the ten-degree incline that makes the bridge unique.

Bridge deck

The bridge surface is composed of two separate decks, a wide vehicular deck carrying two lanes of eastbound traffic, one lane of westbound traffic, and a wide pedestrian deck on the opposite side of the arch from the vehicular deck and slightly elevated. While the redesign of the original concept altered the deck supports, the actual construction of the decks changed only slightly to accommodate the new design.

L-struts

The Main Street bridge also calls for thirteen L-struts, which would attach the arch to the bridge deck. Their original design used tapering geometries which were different for each strut. Creating, designing and testing thirteen distinct struts would have been cost-prohibitive, so engineers simplified the designs to reduce costs. While the aesthetics of the original design changed because of the more uniform strut design, they are similarly appealing and reduce the components' weight by over .

Piers

The final redesign of the Main street bridge was of the piers. The original design called for two 'V-piers', formed by the convergence of the main arch and the secondary arches on either side. This design proved to be nearly impossible to make structurally sound forcing engineers to simplify the piers. To do so they created a 'crescent pier' shape, which removes the two smaller arches on either end and creates a larger pier to provide better support.

Gallery

File:Main Street Bridge, Columbus, Ohio 09.jpg, 1937 bridge specifications plaque File:Main Street Bridge, Columbus, Ohio 01.jpg, Historical plaques File:Main Street Bridge, Columbus, Ohio 05.jpg, Railing from the original bridge File:The Pedestrian Portion, Columbus.jpg, Pedestrian walkway File:Main Street Bridge, Columbus, Ohio 06.jpg, Binoculars for city viewing File:Main Street Bridge at night (Columbus, OH).JPG, Nighttime lighting

References

External links

Main Street Bridge
at Bridges & Tunnels {{Crossings navbox , structure = Crossings , place =

, bridge = Main Street Bridge , bridge signs = , upstream =

Rich Street Bridge The Rich Street Bridge is a bridge in Columbus, Ohio, United States, spanning the Scioto River and connecting downtown's Rich Street to Franklinton's Town Street. It carries U.S. Route 62 (US 62) and Ohio State Route 3 (SR 3). ...

, upstream signs = US 62

, downstream =

Lower Scioto Rail Bridge Lower may refer to: *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eig ...

, downstream signs = Bridges completed in 2010 Bridges in Columbus, Ohio Bridges of the United States Numbered Highway System Bridges over the Scioto River Concrete bridges in the United States Downtown Columbus, Ohio Open-spandrel deck arch bridges in the United States Road bridges in Ohio Steel bridges in the United States Tied arch bridges in the United States U.S. Route 62