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33-525: The Hernando de Soto Bridge is a tied-arch bridge carrying Interstate 40 across the Mississippi River between West Memphis, Arkansas , and Memphis , Tennessee . The design is a continuous cantilevered cable-stayed steel through arch, with bedstead endposts. Memphians also call the bridge the "New Bridge", as it is newer than the Memphis & Arkansas Bridge (carrying Interstate 55 ) downstream, and

66-434: A bridge pier on the approach bridge west of the river had settled overnight, and the bridge was subsequently closed to perform a precautionary inspection. The bridge was reopened later that day. Between 2000 and 2015, the bridge underwent a seismic retrofitting project, allowing it to withstand a 7.7 magnitude earthquake, the similar magnitude of earthquakes during the 1811–12 New Madrid earthquakes . The retrofit project

99-520: A fracture control plan. [....] • Other hydrogen cracks were identified on the interior tie girder surface at similar thickness transitions throughout the bridge. These hydrogen cracks were comparatively shallow (<3/16 in.), and those observed cracks tended to travel as intergranular cracks through the GCHAZ [grain coarsened heat affected zone] until they arrested in material with lower hardness and greater toughness and hydrogen tolerance. [....] • Given

132-499: A much larger share of the cost due to Tennessee's larger population. Both states eventually agreed to a compromise where Tennessee funded 60% of the cost and Arkansas the remaining 40%. Both states also initially disagreed on the design of the bridge; the original design called for longer through arches and a lower vertical clearance. Construction of the Hernando de Soto Bridge began on May 2, 1967. Initially planned for completion in 1971,

165-427: A remote switch to toggle the lights on and off briefly while the vessel passes under the bridge. During the 2011 Mississippi River floods , the bridge became dark for about 2 months because the transformers that supply the electricity for the lights were removed to prevent damage to them by flood waters. The bridge was re-lit in a ceremony which occurred on June 21, 2011. On August 23, 2007, an inspector discovered that

198-523: A single span, two tied-arches are placed in parallel alongside the deck, so the deck lies in between the arches. Axial tied-arch or single tied-arch bridges have at most one tied-arch per span that is usually centered in the middle of the bridge deck. An example for this is Hoge Brug in Maastricht. Since it has hinged hangers it might also classify as a Nielsen bridge who held a patent on tied-arch bridges with hinged hangers from 1926. Some designs tilt

231-410: A tied-arch bridge deck are translated, as tension, by vertical ties between the deck and the arch, tending to flatten it and thereby to push its tips outward into the abutments, like for other arch bridges. However, in a tied-arch or bowstring bridge, these movements are restrained not by the abutments but by the strengthened chord, which ties these tips together, taking the thrusts as tension, rather like

264-520: A tied-arch; however, the bowstring truss behaves as truss , not an arch . The visual distinction is a tied-arch bridge will not have substantial diagonal members between the vertical members. In a 1978 advisory issued by the Federal Highway Administration (FHWA), the FHWA noted that tied-arch bridges are susceptible to problems caused by poor welds at the connection between the arch rib and

297-510: Is also a means to protect the bridge as it is located within 100 miles (161 km) of the New Madrid Seismic Zone and serves as a major cargo route and traffic thoroughfare across the river. As part of this project, the main span, approaches, and ramps for the downtown exit were retrofitted. A bridge about 1 mile (1.6 km) west of the main span was rebuilt with earthquake considerations in mind. The federal government covered 80% of

330-632: Is the Fremont Bridge in Portland, Oregon which is the second-longest tied-arch bridge in the world and also classifies as a through arch bridge . The Chaotianmen Bridge in Chongqing is a tied-arch, through arch and a truss arch bridge . Contrarily, the Hart Bridge uses a cantilevered trussed arch, it is self-anchored , but its arch is non-tied. In particular the bridge deck is suspended, but does not tie

363-585: The Fremont Bridge in Portland, Oregon and the first "computer-designed" bridge of this type, the Fort Pitt Bridge in Pittsburgh, Pennsylvania . Both the tied-arch bridge and the self-anchored suspension bridge place only vertical loads on the anchorage, and so are suitable where large horizontal forces are difficult to anchor. Some tied-arch bridges only tie a segment of the main arch directly and prolong

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396-538: The " M Bridge ", due to its distinctive shape. It is of similar construction to the Sherman Minton Bridge between Louisville, Kentucky , and New Albany, Indiana (except that it consists of a single level deck). Preliminary planning for the river crossing began in 1960 as part of Interstate 40 alignment studies for the Memphis - Little Rock corridor, which was constructed in segments between 1963 and 1968. Before

429-471: The 48-year service life of this structure, the fact that the subject fracture occurred in three separate phases over several years, the recent inspection efforts to identify welding defects at the tie girder thickness transition welds, and no evidence of observed fatigue crack growth during this study, it is highly unlikely that an additional major fracture of a similar tie girder thickness transition weld will occur. Tied-arch bridge Thrusts downwards on

462-545: The Harahan Bridge and display various color patterns dependent upon special occasions or requests. Both displays have been created under an initiative called "Mighty Lights." The $ 14 million privately funded project was completed in 2018. On May 11, 2021, an inspection discovered a partially fractured tie girder on the Span A North truss. Two of the four plates comprising the box-shaped tension tie member were completely fractured and

495-563: The Hernando de Soto Bridge was completed, traffic going across the river was carried across the Mississippi River by the Interstate 55/US Highway 64/70/79/61 Memphis & Arkansas Bridge crossing, located 2 miles (3.2 km) southwest. The two states initially feuded over the cost of paying for the bridge. Tennessee officials believed that both states should equally pay for the bridge, while Arkansas officials wanted Tennessee to shoulder

528-403: The Mississippi River and died south of Memphis. At night, the bridge was illuminated by 200 sodium vapor lights along its "M" structure. The bridge was first illuminated on September 5, 1986, after $ 373,000 of private funds had been raised to fund the cost and installation of the lights. Due to some river traffic having issues with the lights at night reflecting on the water, the city installed

561-666: The arch ends. Tied arch bridges may consist of successively lined up tied arches in places where a single span is not sufficient. An example for this is the Godavari Arch Bridge in Rajahmundry, India. It has four separate supports on each pier and carries the South Central Railway Line of India. It was designed for 250 km/h rail services. Like for multi-span continuous beam bridges the tying chord continually spans over all piers. The arches feet coincide (fuse) at

594-413: The arches outward or inward with respect to the axis running along the bridge deck. In analogy to twin bridges , two tied arch bridges erected side by side to increase traffic capacity, but structurally independent, may be referred to by tied arch twin bridges . Each in return may use a single- or multi-span, discrete or continuous tied-arch design. A bowstring truss bridge is similar in appearance to

627-413: The arches. Contrarily each abutment on the riverbanks supports a single arch end only, in the middle of the deck. The tying chord(s) consist of a composite deck structure. Four post tensioned coil steel cables, two to each side of the walking deck, are locked in place by orthogonally run steel beams every 7.5 meters. The hangers are joined to each of these beams between each cable pair. Since the beams extend

660-439: The bottom plate was partially fractured, leaving only the inside-facing plate intact. Since the severely compromised girder was one of a pair of load-bearing tension members that were critical to the structural integrity of the bridge's tied-arch design, the bridge was structurally unsound and at risk of collapse. The inspecting engineer called 9-1-1 and told authorities to shut down the bridge immediately. Vehicular traffic across

693-420: The bridge and river traffic under the bridge were halted while engineers inspected the entire bridge for other issues, and analyzed the structure. River traffic under the bridge resumed three days later on May 14. Initial repairs that affixed steel plates on both sides of the affected girder were completed on May 25. The second phase consisted of the installation of additional steel plating and removal of part of

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726-458: The bridge piers. A good visual indication are shared supports at the piers. Dynamic loads are distributed between spans. This type may be combined with the shouldered tied-arch design discussed above. An example for this is Dashengguan Bridge in Nanjing, China. Its two main arches are shouldered by short auxiliary arches. It is both, a (rigid) tied-arch and a cantilevered trussed arch design. Because

759-677: The cost, with Tennessee contributing 12% and Arkansas 8%. It was announced after the opening of the Big River Crossing along the Harahan Bridge to the south that the existing sodium vapor lights along the Hernando Desoto Bridge would be replaced with a new LED lighting display, thus making the Hernando de Soto Bridge the second bridge over the Mississippi River to be lit as such after the Harahan. The new display can be lit in sync with

792-519: The damaged beam. A new inspection of the bridge found "nothing of concern". The eastbound lanes reopened on July 31, 2021, the westbound lanes on August 2, 2021. During the closure, vehicle traffic utilized the nearby Memphis & Arkansas Bridge ( I-55 ) as an alternate route in the Memphis area, as well as the Caruthersville Bridge ( I-155 ) to the north and the Helena Bridge ( US 49 ) to

825-503: The mandated hands-on—that is, within arm's length—inspections that should have occurred every two years had not been undertaken. The responsible inspector was subsequently fired. An engineering analysis revealed the fracture was the result of two particularly wide and poorly done weld repairs in the same spot during "fabrication" (construction) that, along with other poor welds elsewhere on the bridge, had been identified and repaired; there were consequently no further concerns. Key findings of

858-465: The project experienced multiple delays. The double-arch bridge was opened to automobile traffic on August 2, 1973. A dedication ceremony for the bridge occurred on August 17, 1973. Initially expected to be only $ 12 million (equivalent to $ 80.3 million in 2024), the final price tag was approximately $ 57 million (equivalent to $ 299 million in 2024). The bridge is named for 16th century Spanish explorer Hernando de Soto , who explored this stretch of

891-501: The report included the following four points: • Metallographic examination of the fracture surfaces identified two weld repairs from fabrication that were much wider and contained weld metal deposit sequencing that differed from other side plate thickness transition welds in the bridge. • The weld repairs caused two large hydrogen cracks as a result of the inherent restraint, improper preheat and/or use of contaminated welding electrodes commonly associated with weld repairs performed without

924-535: The south as alternates elsewhere in the Mid-South. Investigators received amateur photos taken from the river below as early as 2016 that already showed damage at the same site. And according to the Arkansas Department of Transportation , review of archived drone footage taken during a May 2019 bridge inspection, two years before the damage was discovered, also showed the fracture. The department further found that

957-467: The strengthened chord to tie to the top ends of auxiliary (half-)arches . The latter usually support the deck from below and join their bottom feet to those of the main arch(es). The supporting piers at this point may be slender, because the outward-directed horizontal forces of main and auxiliary arch ends counterbalance. The whole structure is self-anchored . Like the simple case it exclusively places vertical loads on all ground-bound supports. An example

990-578: The string of a bow that is being flattened. Therefore, the design is also called a bowstring-arch or bowstring-girder bridge . The elimination of horizontal forces at the abutments allows tied-arch bridges to be constructed with less robust foundations; thus they can be situated atop elevated piers or in areas of unstable soil . In addition, since they do not depend on horizontal compression forces for their integrity, tied-arch bridges can be prefabricated offsite, and subsequently floated, hauled or lifted into place. Notable bridges of this type include

1023-462: The tie girders, and at the connection between the arch and vertical ties. In addition, problems with electroslag welds , while not isolated to tied-arch bridges, resulted in costly, time-consuming and inconveniencing repairs. The structure as a whole was described as nonredundant : failure of either of the two tie girders would result in failure of the entire structure. Memphis %26 Arkansas Bridge Too Many Requests If you report this error to

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1056-471: The traffic runs through the structural envelope, it is also a through arch bridge. Guandu Bridge in New Taipei, Taiwan is a non-trussed example with three main arches augmented by two auxiliary arch segments at the bridge portals. The Infinity Bridge uses two arches of different height and span length that both bifurcate before their apex. Above its single, middle-displaced river pier the deck lies between

1089-474: The width of the post-tensioned concrete deck, the tensing cable pairs remain visible. A close-up of the river pier shows that the structural dead load is tied per span: The larger arch span uses thicker tensing cables and the reflex segments are not suspended from, but supported by steel beams, essentially completing the arches at the river pier. However, for dynamic and non-uniform loads the visually defining arch continuations must not be neglected. Usually, for

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