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51-569: Navajo Bridge is the name of twin steel spandrel arch bridges that cross the Colorado River in the Grand Canyon National Park (near Lees Ferry ) in northern Coconino County , Arizona , United States. The newer of the two spans carries vehicular traffic on U.S. Route 89A (US 89A) over Marble Canyon between Bitter Springs and Jacob Lake , allowing travel into a remote Arizona Strip region north of

102-474: A cost of $ 14.7 million. A formal dedication was held on September 14, 1995. The original Navajo Bridge is still open to pedestrian and equestrian use, and an interpretive center has been constructed on the west side to showcase the historical nature of the bridge and early crossing of the Colorado River. The original bridge has been designated as a Historic Civil Engineering Landmark , and was placed on

153-512: A deck arch bridge. Any part supported from arch below may have spandrels that are closed or open. The Sydney Harbour Bridge and the Bayonne Bridge are a through arch bridge which uses a truss type arch. Also known as a bowstring arch, this type of arch bridge incorporates a tie between two opposite ends of the arch. The tie is usually the deck and is capable of withstanding the horizontal thrust forces which would normally be exerted on

204-462: A greater passage for flood waters. Bridges with perforated spandrels can be found worldwide, such as in China ( Zhaozhou Bridge , 7th century). Greece ( Bridge of Arta , 17th century) and Wales ( Cenarth Bridge , 18th century). In more modern times, stone and brick arches continued to be built by many civil engineers, including Thomas Telford , Isambard Kingdom Brunel and John Rennie . A key pioneer

255-552: A new collection of innovations to champion every two years that merit accelerated deployment. Among the approaches promoted by the EDC effort are: adaptive traffic control to reduce fuel consumption and improve travel time reliability ; alternative intersection design; prefabricated bridge elements and systems; high-friction surface treatments; warm mix asphalt; ultra-high-performance concrete; virtual public involvement; and time-saving strategies such as rapid bridge replacement . Since

306-447: A number were segmental arch bridges (such as Alconétar Bridge ), a bridge which has a curved arch that is less than a semicircle. The advantages of the segmental arch bridge were that it allowed great amounts of flood water to pass under it, which would prevent the bridge from being swept away during floods and the bridge itself could be more lightweight. Generally, Roman bridges featured wedge-shaped primary arch stones ( voussoirs ) of

357-448: A quantity of fill material (typically compacted rubble) above the arch in order to increase this dead-weight on the bridge and prevent tension from occurring in the arch ring as loads move across the bridge. Other materials that were used to build this type of bridge were brick and unreinforced concrete. When masonry (cut stone) is used the angles of the faces are cut to minimize shear forces. Where random masonry (uncut and unprepared stones)

408-551: A question based on the LTPP data. In 2010, FHWA launched the Every Day Counts (EDC) initiative to identify and deploy innovations to reduce project delivery time, enhance safety, and protect the environment. EDC is a state-based model that rapidly deploys proven, yet underutilized innovations. FHWA works with State transportation departments, local governments, tribes, private industry, and other stakeholders to identify

459-415: A result, masonry arch bridges are designed to be constantly under compression, so far as is possible. Each arch is constructed over a temporary falsework frame, known as a centring . In the first compression arch bridges, a keystone in the middle of the bridge bore the weight of the rest of the bridge. The more weight that was put onto the bridge, the stronger its structure became. Masonry arch bridges use

510-430: A three-hinged bridge has hinged in all three locations. Most modern arch bridges are made from reinforced concrete . This type of bridge is suitable where a temporary centring may be erected to support the forms, reinforcing steel, and uncured concrete. When the concrete is sufficiently set the forms and falseworks are then removed. It is also possible to construct a reinforced concrete arch from precast concrete , where

561-428: Is a masonry, or stone, bridge where each successively higher course (layer) cantilevers slightly more than the previous course. The steps of the masonry may be trimmed to make the arch have a rounded shape. The corbel arch does not produce thrust, or outward pressure at the bottom of the arch, and is not considered a true arch . It is more stable than a true arch because it does not have this thrust. The disadvantage

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612-573: Is still used by the local populace. The well-preserved Hellenistic Eleutherna Bridge has a triangular corbel arch. The 4th century BC Rhodes Footbridge rests on an early voussoir arch. Although true arches were already known by the Etruscans and ancient Greeks , the Romans were – as with the vault and the dome – the first to fully realize the potential of arches for bridge construction. A list of Roman bridges compiled by

663-432: Is that this type of arch is not suitable for large spans. In some locations it is necessary to span a wide gap at a relatively high elevation, such as when a canal or water supply must span a valley. Rather than building extremely large arches, or very tall supporting columns (difficult using stone), a series of arched structures are built one atop another, with wider structures at the base. Roman civil engineers developed

714-402: Is used they are mortared together and the mortar is allowed to set before the falsework is removed. Traditional masonry arches are generally durable, and somewhat resistant to settlement or undermining. However, relative to modern alternatives, such bridges are very heavy, requiring extensive foundations . They are also expensive to build wherever labor costs are high. The corbel arch bridge

765-685: The Manual on Uniform Traffic Control Devices (MUTCD), which is used by most highway agencies in the United States. The MUTCD provides such standards as the size, color and height of traffic signs , traffic signals and road surface markings . Long-Term Pavement Performance (LTPP) is a program supported by the FHWA to collect and analyse road data. The LTPP program was initiated by the Transportation Research Board (TRB) of

816-495: The National Register of Historic Places on August 13, 1981. California condors were reintroduced to the area in 1996 and can sometimes be seen on and around Navajo Bridge. Construction started June 30, 1927 Bridge opened to traffic January 12, 1929 Total length: 834 feet (254 m) Steel arch length: 616 feet (188 m) Arch rise: 90 feet (27 m) Height above river: 467 feet (142 m) Width of

867-634: The National Research Council (NRC) in the early 1980s. The FHWA with the cooperation of the American Association of State Highway and Transportation Officials (AASHTO) sponsored the program. As a result of this program, the FHWA has collected a huge database of road performance. The FHWA and the ASCE hold an annual contest known as LTPP International Data Analysis Contest , which is based on challenging researchers to answer

918-559: The Office of Road Inquiry , Office of Public Roads and the Bureau of Public Roads . With the coming of the bicycle in the 1890s, interest grew regarding the improvement of streets and roads in America. The traditional method of putting the burden on maintaining roads on local landowners was increasingly inadequate. In 1893, the federal Office of Road Inquiry (ORI) was founded; in 1905, it

969-412: The Colorado River below. Supervisors had rejected the idea of rigging safety netting, believing that it would catch on fire from falling hot rivets . The original bridge is 834 feet (254 m) in length, with a maximum height of 467 feet (142 m) from the canyon floor. The roadway offers an 18-foot (5.5 m) surface width with a load capacity of 22.5 tons (although the posted legal weight limit

1020-468: The Colorado River including the North Rim of Grand Canyon National Park . Prior to completion of the first Navajo Bridge, one of the only Colorado River crossings between Arizona and Utah was located about 5 miles (8.0 km) upstream from the bridge site, at the mouth of Glen Canyon where Lees Ferry service had operated since 1873. The ferry site had been chosen as the only relatively easy access to

1071-767: The Federal Lands Highway Program (sometimes called "direct fed"), the FHWA provides highway design and construction services for various federal land-management agencies, such as the Forest Service and the National Park Service . In addition to these programs, the FHWA performs and sponsors research in the areas of roadway safety, congestion, highway materials and construction methods, and provides funding to local technical assistance program centers to disseminate research results to local highway agencies. The FHWA also publishes

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1122-436: The abutments of an arch bridge. The deck is suspended from the arch. The arch is in compression, in contrast to a suspension bridge where the catenary is in tension. A tied-arch bridge can also be a through arch bridge. An arch bridge with hinges incorporated to allow movement between structural elements. A single-hinged bridge has a hinge at the crown of the arch , a two-hinged bridge has hinges at both springing points and

1173-793: The acclaimed Florentine segmental arch bridge Ponte Vecchio (1345) combined sound engineering (span-to-rise ratio of over 5.3 to 1) with aesthetical appeal. The three elegant arches of the Renaissance Ponte Santa Trinita (1569) constitute the oldest elliptic arch bridge worldwide. Such low rising structures required massive abutments , which at the Venetian Rialto bridge and the Fleischbrücke in Nuremberg (span-to-rise ratio 6.4:1) were founded on thousands of wooden piles, partly rammed obliquely into

1224-416: The arch and the deck is known as the spandrel . If the spandrel is solid, usually the case in a masonry or stone arch bridge, the bridge is called a closed-spandrel deck arch bridge . If the deck is supported by a number of vertical columns rising from the arch, the bridge is known as an open-spandrel deck arch bridge . The Alexander Hamilton Bridge is an example of an open-spandrel arch bridge. Finally, if

1275-400: The arch is built in two halves which are then leaned against each other. Many modern bridges, made of steel or reinforced concrete, often bear some of their load by tension within their structure. This reduces or eliminates the horizontal thrust against the abutments and allows their construction on weaker ground. Structurally and analytically they are not true arches but rather a beam with

1326-422: The arch supports the deck only at the top of the arch, the bridge is called a cathedral arch bridge . This type of bridge has an arch whose base is at or below the deck, but whose top rises above it, so the deck passes through the arch. The central part of the deck is supported by the arch via suspension cables or tie bars, as with a tied-arch bridge . The ends of the bridge may be supported from below, as with

1377-625: The bridge an unusually flat profile unsurpassed for more than a millennium. Trajan's bridge over the Danube featured open- spandrel segmental arches made of wood (standing on 40 m-high (130 ft) concrete piers). This was to be the longest arch bridge for a thousand years both in terms of overall and individual span length, while the longest extant Roman bridge is the 790 m-long (2,590 ft) long Puente Romano at Mérida . The late Roman Karamagara Bridge in Cappadocia may represent

1428-847: The bridge opened to traffic in 1929. The bridge was paid for by the nascent Arizona State Highway Commission (now the Arizona Department of Transportation ) in cooperation with the United States Department of the Interior 's Bureau of Indian Affairs , as the eastern landing is on the Navajo Nation . The steel spandrel bridge was designed and constructed by the Kansas City Structural Steel Company. During construction, worker Lane McDaniels died after falling 467 feet (142 m) to

1479-414: The design and constructed highly refined structures using only simple materials, equipment, and mathematics. This type is still used in canal viaducts and roadways as it has a pleasing shape, particularly when spanning water, as the reflections of the arches form a visual impression of circles or ellipses. This type of bridge comprises an arch where the deck is completely above the arch. The area between

1530-554: The earliest surviving bridge featuring a pointed arch. In medieval Europe, bridge builders improved on the Roman structures by using narrower piers , thinner arch barrels and higher span-to-rise ratios on bridges. Gothic pointed arches were also introduced, reducing lateral thrust, and spans increased as with the eccentric Puente del Diablo (1282). The 14th century in particular saw bridge building reaching new heights. Span lengths of 40 m (130 ft), previously unheard of in

1581-484: The engineer Colin O'Connor features 330 Roman stone bridges for traffic, 34 Roman timber bridges and 54 Roman aqueduct bridges , a substantial part still standing and even used to carry vehicles. A more complete survey by the Italian scholar Vittorio Galliazzo found 931 Roman bridges, mostly of stone, in as many as 26 countries (including former Yugoslavia ). Roman arch bridges were usually semicircular , although

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1632-499: The grounds to counteract more effectively the lateral thrust. In China, the oldest existing arch bridge is the Zhaozhou Bridge of 605 AD, which combined a very low span-to-rise ratio of 5.2:1, with the use of spandrel arches (buttressed with iron brackets). The Zhaozhou Bridge, with a length of 167 feet (51 m) and span of 123 feet (37 m), is the world's first wholly stone open-spandrel segmental arch bridge, allowing

1683-443: The history of masonry arch construction, were now reached in places as diverse as Spain ( Puente de San Martín ), Italy ( Castelvecchio Bridge ) and France ( Devil's bridge and Pont Grand ) and with arch types as different as semi-circular, pointed and segmental arches. The bridge at Trezzo sull'Adda , destroyed in the 15th century, even featured a span length of 72 m (236 ft), not matched until 1796. Constructions such as

1734-527: The inception of EDC, each state has used 26 or more of the 57 innovations and some states have deployed more than 45. Many of these practices have become mainstream practices across the country. The Federal Highway Administration is overseen by an administrator appointed by the President of the United States by and with the consent of the United States Senate . The administrator works under

1785-471: The many local interests. Issues included preservation of sacred Navajo land, endangered plant species in Marble Canyon, and the possibility of construction debris entering the river. The original proposal called for merely widening and fortifying the 1928 bridge, but this was ultimately rejected as not sufficient to meet contemporary federal highway standards. Replacement became the only option, and it

1836-844: The new U.S. Department of Transportation . The FHWA took over the functions of the Bureau of Public Roads the following year. The FHWA's role in the Federal-aid Highway Program is to oversee federal funds to build and maintain the National Highway System (primarily Interstate highways , U.S. highways and most state highways). This funding mostly comes from the federal gasoline tax and mostly goes to state departments of transportation . The FHWA oversees projects using these funds to ensure that federal requirements for project eligibility, contract administration and construction standards are adhered to. Under

1887-479: The only ones to construct bridges with concrete , which they called Opus caementicium . The outside was usually covered with brick or ashlar , as in the Alcántara Bridge . The Romans also introduced segmental arch bridges into bridge construction. The 330 m-long (1,080 ft) Limyra Bridge in southwestern Turkey features 26 segmental arches with an average span-to-rise ratio of 5.3:1, giving

1938-646: The organization was once again named the Bureau of Public Roads; it was placed under the Department of Commerce . From 1917 through 1941, 261,000 miles of highways were built with $ 3.17 billion in federal aid and $ 2.14 billion in state and local funds. The Federal Highway Administration was created on October 15, 1966, along with the Bureau of Motor Carrier Safety and the National Highway Safety Bureau (now known as National Highway Traffic Safety Administration ), as part of

1989-516: The river for both northbound and southbound travelers. By the 1920s, automobile traffic began using the ferry, though it was not considered a safe and reliable crossing due to adverse weather and flooding regularly preventing its operation. The bridge was officially named the Grand Canyon Bridge when it was dedicated on June 14–15, 1929. The state legislature changed the name to Navajo Bridge five years later in 1934. The original bridge

2040-450: The roadway: 18 feet (5.5 m) Amount of steel: 2,400,000 pounds (1,100,000 kg) Amount of concrete: 500 cubic yards (382 m) Amount of steel reinforcement: 82,000 pounds (37,000 kg) Construction cost: $ 390,000 (equivalent to $ 6.92 million in 2023) Total length: 909 feet (277 m) Steel arch length: 726 feet (221 m) Arch rise: 90 feet (27 m) Height above river: 470 feet (143 m) Width of

2091-585: The roadway: 44 feet (13 m) Amount of steel: 3,900,000 pounds (1,800,000 kg) Amount of concrete: 1,790 cubic yards (1,370 m) Amount of steel reinforcement: 434,000 pounds (197,000 kg) Construction cost $ 14.7 million (equivalent to $ 29.39 million in 2023) Arch bridge Possibly the oldest existing arch bridge is the Mycenaean Arkadiko Bridge in Greece from about 1300 BC. The stone corbel arch bridge

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2142-639: The same in size and shape. The Romans built both single spans and lengthy multiple arch aqueducts , such as the Pont du Gard and Segovia Aqueduct . Their bridges featured from an early time onwards flood openings in the piers, e.g. in the Pons Fabricius in Rome (62 BC), one of the world's oldest major bridges still standing. Roman engineers were the first and until the Industrial Revolution

2193-455: The shape of an arch. See truss arch bridge for more on this type. A modern evolution of the arch bridge is the long-span through arch bridge . This has been made possible by the use of light materials that are strong in tension such as steel and prestressed concrete. "The Romans were the first builders in Europe, perhaps the first in the world, fully to appreciate the advantages of the arch,

2244-417: The traffic flow was too great for the original bridge and that a new solution was needed. The sharp corners in the roadway on each side of the approach had become a safety hazard due to low visibility, and deficiencies resulting from the original design's width and load capacity specifications were becoming problematic. The bridge had also become part of US 89A. Deciding on a solution was difficult, due to

2295-401: The vault and the dome." Federal Highway Administration The Federal Highway Administration ( FHWA ) is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two programs, the Federal-aid Highway Program and the Federal Lands Highway Program. Its role had previously been performed by

2346-402: Was Jean-Rodolphe Perronet , who used much narrower piers, revised calculation methods and exceptionally low span-to-rise ratios. Different materials, such as cast iron , steel and concrete have been increasingly used in the construction of arch bridges. Stone, brick and other such materials are strong in compression and somewhat so in shear , but cannot resist much force in tension . As

2397-604: Was 40 tons). During the design phase, a wider roadway was considered, but ultimately rejected, as it would have required a costly third arch to be added to the design, and the vehicles of the time did not require a wider road. When the Bridge officially opened on January 12, 1929, the Flagstaff paper proclaimed it "the biggest news in Southwest history." By 1984, however, Arizona Department of Transportation officials decided that

2448-665: Was changed to the Bureau of Public Roads . The following year, federal aid was first made available to improve post roads and promote general commerce: $ 75 million over five years, issued through the BPR in cooperation with the state highway departments. In 1939, BPR was renamed to the Public Roads Administration (PRA) and shifted to the Federal Works Agency . After the FWA was abolished in 1949,

2499-428: Was closed to vehicular traffic after the new span opened in 1995. The old span is still open for pedestrian and equestrian use. The dual spans of Navajo Bridge are tied at ninth place among the highest bridges in the United States with nearly identical heights of 467 feet (142.3 m) for the original span, and 470 feet (143.3 m) for the second span. Construction of the original Navajo Bridge began in 1927, and

2550-610: Was eventually decided to entirely discontinue vehicular traffic on the original bridge. A new bridge would be built immediately next to the original and have a considerably similar visual appearance, but would conform to modern highway codes. The new steel arch bridge was commissioned by the Arizona Department of Transportation and the Federal Highway Administration , and was completed in May 1995, at

2601-870: Was renamed the Office of Public Roads (OPR) and made a division of the United States Department of Agriculture . Demands grew for local and state government to take charge. With the coming of the automobile, urgent efforts were made to upgrade and modernize dirt roads designed for horse-drawn wagon traffic. In 1910, the American Association for Highway Improvement was organized. Funding came from automobile registration, and taxes on motor fuels, as well as state aid. By 1914, there were 2.4 million miles of rural dirt rural roads; 100,000 miles had been improved with grading and gravel, and 3,000 miles were given high-quality surfacing. The rapidly increasing speed of automobiles, and especially trucks, made maintenance and repair high-priority items. In 1915, OPR's name

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