A cantilever bridge is a bridge built using structures that project horizontally into space, supported on only one end (called cantilevers ). For small footbridges , the cantilevers may be simple beams ; however, large cantilever bridges designed to handle road or rail traffic use trusses built from structural steel , or box girders built from prestressed concrete .
17-610: The Murray Baker Bridge is a landmark cantilever bridge that carries Interstate 74 (I-74) and Illinois Route 29 (IL 29) over the Illinois River from downtown Peoria to East Peoria in central Illinois . According to the Illinois Department of Transportation, the Murray Baker Bridge was built in 1958, and had an original length of 3,216 feet (980 m). The bridge itself
34-423: A balanced cantilever ; when they attach to a solid foundation, the counterbalancing arms are called anchor arms . Thus, in a bridge built on two foundation piers, there are four cantilever arms: two which span the obstacle, and two anchor arms that extend away from the obstacle. Because of the need for more strength at the balanced cantilever's supports, the bridge superstructure often takes the form of towers above
51-472: A bridge in Illinois is a stub . You can help Misplaced Pages by expanding it . Cantilever bridge The steel truss cantilever bridge was a major engineering breakthrough when first put into practice, as it can span distances of over 1,500 feet (450 m), and can be more easily constructed at difficult crossings by virtue of using little or no falsework . Engineers in the 19th century understood that
68-505: A bridge that could handle differential settlement of the foundations. Engineers could more easily calculate the forces and stresses with a hinge in the girder. Heinrich Gerber was one of the engineers to obtain a patent for a hinged girder (1866) and is recognized as the first to build one. The Hassfurt Bridge over the Main river in Germany with a central span of 124 feet (38 metres)
85-402: A bridge that was continuous across multiple supports would distribute the loads among them. This would result in lower stresses in the girder or truss and meant that longer spans could be built. Several 19th-century engineers patented continuous bridges with hinge points mid-span. The use of a hinge in the multi-span system presented the advantages of a statically determinate system and of
102-629: Is a single cantilever bridge, with two lanes in each direction. Because it has no shoulders, the Baker Bridge is not up to modern Interstate standards . The bridge is named for Murray M. Baker , who was the first vice president of the company that eventually became Caterpillar . Baker convinced the Holt Manufacturing Company to move to Peoria in 1909. Holt merged with C.L. Best Gas Tractor Co. and became Caterpillar in 1925. The bridge underwent repairs in 1984. As part of
119-465: The Navajo Bridge ) are built using pure cantilever spans from each side, with neither falsework below nor temporary supporting towers and cables above. These are then joined with a pin, usually after forcing the union point apart, and when jacks are removed and the bridge decking is added the bridge becomes a truss arch bridge . Such unsupported construction is only possible where appropriate rock
136-578: The Upgrade 74 reconstruction project in 2005, the span's length was shortened to 3,036 feet (925 m) to make room for new entrance ramps on the west side of the river. On January 3, 2006, the Illinois Department of Transportation and the chief design consultant for the truss shortening, Alfred Benesch & Company , were awarded the 2006 Eminent Conceptor Award by the American Council of Engineering Companies of Illinois (ACEC-IL). The project
153-424: The Murray Baker Bridge rehabilitation was completed on schedule and reopened to the public on October 31, 2020. The project, one of the first under Governor Pritzker's historic, bipartisan Rebuild Illinois capital program, improved the critical travel corridor by closing the work zone to all traffic for seven months instead of multiple construction seasons. The $ 42.2 million rehabilitation project removed and replaced
170-415: The action of the outer foundations. Cantilever Bridge.—A structure at least one portion of which acts as an anchorage for sustaining another portion which extends beyond the supporting pier. A simple cantilever span is formed by two cantilever arms extending from opposite sides of an obstacle to be crossed, meeting at the center. In a common variant, the suspended span , the cantilever arms do not meet in
187-423: The center; instead, they support a central truss bridge which rests on the ends of the cantilever arms. The suspended span may be built off-site and lifted into place, or constructed in place using special travelling supports. A common way to construct steel truss and prestressed concrete cantilever spans is to counterbalance each cantilever arm with another cantilever arm projecting the opposite direction, forming
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#1732780419704204-464: The existing bridge deck, repaired structural steel, repainted lower portions of the bridge and installed new lighting, resulting in a smoother, safer ride for commuter and freight traffic. As part of a joint effort with the City of Peoria, energy-efficient decorative lighting was added to enhance a community focal point. The Murray Baker Bridge carries almost 68,000 vehicles a day. This article about
221-648: The foundation piers. The Commodore Barry Bridge is an example of this type of cantilever bridge. Steel truss cantilevers support loads by tension of the upper members and compression of the lower ones. Commonly, the structure distributes the tension via the anchor arms to the outermost supports, while the compression is carried to the foundations beneath the central towers. Many truss cantilever bridges use pinned joints and are therefore statically determinate with no members carrying mixed loads. Prestressed concrete balanced cantilever bridges are often built using segmental construction . Some steel arch bridges (such as
238-431: The structural principles of the suspended span cantilever by sitting in chairs and supporting their colleague, Kaichi Watanabe , in between them, using just their arms and wooden poles. The suspended span, where Watanabe sits, is in the center. The wooden poles resist the compression of the lower chord , while the outstretched arms support the tension of the upper chord. The placement of the brick counterweights demonstrates
255-574: Was 275 feet (84 metres) deep and took full advantage of the fact that falsework, or temporary support, is not needed for the main span of a cantilever bridge. The Forth Bridge is a notable example of an early cantilever bridge. This bridge held the record for longest span in the world for twenty-nine years until it was surpassed by the Quebec Bridge . The engineers responsible for the bridge, Sir Benjamin Baker and Sir John Fowler , demonstrated
272-550: Was completed in 1867 and is recognized as the first modern cantilever bridge. The High Bridge of Kentucky by C. Shaler Smith (1877), the Niagara Cantilever Bridge by Charles Conrad Schneider (1883) and the Poughkeepsie Bridge by John Francis O'Rourke and Pomeroy P. Dickinson (1889) were all important early uses of the cantilever design. The Kentucky River Bridge spanned a gorge that
289-533: Was picked out of a larger group of Honor Award recipients. The designer was also awarded the 2007 Prize Bridge Award by the National Steel Bridge Alliance (NSBA). The bridge was closed for construction on March 29, 2020. By removing traffic from the work zone, the repairs were completed in just one construction season, reducing the overall project cost and eliminating a safety risk to workers and motorists. Following extensive renovations,
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