A arch bridge is a bridge with a buffer at each end of a curved arch. The curved bridge works by moving the bridge's weight and load partially into the horizontal impulse held by the abutment on both sides. A viaduct (long bridge) can be made from a series of arches, although other more economical structures are commonly used today.
Video Arch bridge
Histori
Probably the oldest arch bridge available is the Arkadiko Mycenaean bridge in Greece from about 1300 BC. Corbel arch stone bridge is still used by locals. The well-preserved Eleutherna Hellenistic Bridge has triangle-shaped triangle arches. The 4th century BC Rhodes Footbridge is located in the early voussoir arch.
Although the actual curvature was already known to the Etruscans and the ancient Greeks, the Romans - as with domes and domes - were the first to fully realize the potential of the arch for the construction of the bridge. The list of Roman bridges drawn up by engineer Colin O'Connor has 330 Roman stone bridges for traffic, 34 Roman wooden bridges and 54 Roman waterway bridges, most still standing and even used for transporting vehicles. A more complete survey by Italian scientist, Vittorio Galliazzo, found 931 Roman bridges, mostly of rock, in as many as 26 countries (including the former Yugoslavia).
Roman curved bridges are usually semicircular, though some are segmental curved bridges (such as AlconÃÆ' Â © tar Bridge), bridges that have curved arches that are less than half a circle. The advantage of a segmental curve bridge is that it allows large flood waters passing under it, which will prevent the bridge from being washed away during the flood and the bridge itself can be lighter. Generally, Roman bridges display the main wedge-shaped arch bricks (voussoirs) of the same size and shape. The Romans built both single spans and several long waterways, such as the Pont du Gard and Segovia Water Channel. Their bridges are displayed from the time of the onward and beyond the flood openings on the dock, for example at Pons Fabricius in Rome (62 BC), one of the oldest large bridges in the world still standing.
Roman engineers were the first and until the only industrial revolution that built bridges with concrete, which they called Opus caementicium. Remarkably covered with brick or ashlar, as in the Alcantara bridge.
The Romans also introduced a segmental curve bridge into the bridge construction. The 330 m (1,080 feet) Limyra bridge in southwest Turkey features 26 segmental arches with an average 5.3: 1 range-to-ride ratio, providing an unparalleled flat profile bridge that is unparalleled for over a millennium. The Trajan Bridge on top of the Danube displays wooden open segmental arches (standing on a 40 m high concrete pier). It is the longest arch bridge for a thousand years both in terms of the overall span and individual length, while the longest surviving Roman bridge is Puente Romano 790 m (length 2,590 feet) in MÃÆ'Â © rida. The final Roman Karamagara bridge in Cappadocia may be the earliest surviving bridge featuring a pointed arch.
In medieval Europe, bridge builders increased in Roman structure by using narrower pillars, thinner curvature barrels and higher ranges to increase the ratio of bridges. The Gothic arch gate was also introduced, reducing lateral impulse, and increased spans such as the eccentric Puente del Diablo (1282).
The 14th century in particular saw the bridge building reach new heights. The 40 m (130 ft) long range, previously unheard of in the history of stone arch construction, now reaches in such diverse places as Spain (Puente de San MartÃÆ'n), Italy (Castelvecchio Bridge) and France (the bridge of Satan and Pont Grand) and with different curved types such as semi-circular, pointed and segmental arches. The bridge at Trezzo sull'Adda, destroyed in the 15th century, even featured a 72 m (236 ft) long range, not matched up to 1796.
Constructions such as the Florentine recessed segment of Florentine recognized by Ponte Vecchio (1345) combine sound engineering (range ratio up to more than 5.3 to 1) with aesthetic appeal. The three elegant arches of the Renaissance Ponte Santa Trinita (1569) are the oldest elliptical arch bridge around the world. Such low-rise structures require a large buffer, which at the Venetian Rialto and FleischbrÃÆ'¼cke bridges in Nuremberg (span-to-rise ratio 6.4: 1) was erected on thousands of wooden piles, some being hit tilted to the base to counter the more effective lateral impulse.
, Australia's oldest operational bridge (1825)]]
In China, the oldest arch bridge available is the Zhaozhou 605 M Bridge, which combines a very low span-to-gain ratio of 5.2: 1, with the use of a spandrel arch (supported by an iron bracket). The Zhaozhou Bridge, with a length of 167 feet (51 m) long and 123 feet (37 m), is the world's first open-stone segmental arch bridge, allowing a larger trajectory for flood waters. Bridges with hollow spandrels can be found all over the world, such as in China (Zhaozhou Bridge, 7th century). Greece (Bridge of Arta, 17th century) and Wales (Cenarth Bridge, 18th century).
In more modern times, rock and brick arches continue to be built by many civil engineers, including Thomas Telford, Isambard Kingdom Brunel and John Rennie. The main pioneer is Jean-Rodolphe Perronet, who uses a lot of narrow docks, revises calculation methods, and very low range-up ratios. Different materials, such as cast iron, steel and concrete have been increasingly used in the construction of arch bridges.
Maps Arch bridge
Simple compression curve bridge
The benefits of simple materials
Stones, bricks and other materials are strong in compression and somewhat so in shear, but can not hold much strength in tension. As a result, the stone arch bridge is designed to be continuously under pressure, as far as possible. Each arch is built on a temporary falsework frame, known as centering. At the first compression curve bridge, the keystone in the center of the bridge bears the bridge's remaining load. The more loads placed on the bridge, the stronger the structure. The massive arch bridge uses a number of fill materials (usually compacted debris) above the arch to increase this dead weight on the bridge and prevent tension from occurring in the arch ring as the load moves across the bridge. Other materials used to build this type of bridge are bricks and concrete that are not reinforced. When masonry (cut stone) is used, the corners of the face are cut to minimize shear forces. Where random stones (stone cut and unprepared) used them mortar together and mortar allowed to set before the falsework was removed.
Traditional masonry arches are generally durable, and somewhat resistant to settlements or damage. However, relative to modern alternatives, such bridges are very heavy, requiring a broad foundation. They are also expensive to build where labor costs are high.
Order of construction
- Where the arch is erected in the creek bed (on the dock or bank), the water is diverted so that the pebbles can be dug first and replaced with a good footing (of strong material). From here, the pier foundation is erected/elevated to the base of the base, a point known as spring.
- Falsework centering (in English English: arch frames) is made, usually of wood and board. Because any curvature of the multi-arch bridge will impose a push on its neighbor, it is necessary that all bridge arches are raised at the same time, or the very wide dock is used. The drive from the arch of the tip is brought to earth by a substantial (vertical) foothold on the canyon wall, or by large planes which tend to form in the ramps to the bridge, which can also be formed from the arch.
- Some arches are (or single arches) built on centralization. After each base of the barrel arch is constructed, the curvature is (or the curvature is) stabilized with the above filler stone, which can be placed in a horizontal walking (layer) bonding program. These can form two outer walls, known as spandrels , which are then filled with the appropriate loose material and ruins.
- The road is lined and parapet walls protectively restrict traffic to the bridge.
Type of arch bridge
Corbel arch bridge
Corbel arch bridge is a stone, or stone, a bridge where each is higher in a row (layer) of cantilevers a little more than before. The steps of masonry can be trimmed to make the arch have a round shape. The corbel curve does not produce impulse, or external pressure at the bottom of the arch, and is not considered a true curvature. This is more stable than the correct curvature because it does not have this impulse. The disadvantage is that this type of curvature is not suitable for large ranges.
Aqueducts and canal viaducts
In some locations, a wide range of pauses at relatively high altitudes, such as when a channel or water supply must reach the valley. Instead of building enormous arches, or very high support columns (difficult to use rocks), a series of curved structures are built one on top of another, with a wider structure at the base. Roman civil engineers developed designs and built very fine structures using only simple materials, tools, and mathematics. This type is still used in channel canals and highways because it has a pleasant shape, especially when it spans water, because the reflection of the curve forms the visual impression of a circle or ellipse.
Jembatan lengkung dek
This type of bridge consists of arches where the deck is actually above the arch. The area between arch and deck is known as spandrel. If the spandrel is solid, usually in stone or bridge, this bridge is called a spandrel-covered bridge . If the deck is supported by a number of vertical columns rising from the arch, this bridge is known as the open-spandrel deck bridge . Alexander Hamilton Bridge is an example of an open-spandrel curve bridge. Finally, if the arch supports the deck only at the top of the arch, this bridge is called the cathedral arch bridge.
Through the arch bridge
This type of bridge has an arch that is essentially at or below the deck, but the top rises above it, so the deck passes through the arch. The center of the deck is supported by arches via a suspension cable or tie bar, as with arch-bound bridges. The ends of the bridge may be supported from below, as with a deck arch bridge. Any portion supported from the arch below may have closed or open spandrels.
Sydney Harbor Bridge is a curved bridge that uses a truss type curve.
Tied-arch bridge
Also known as bow arcs, this type of arch bridge combines a tie between two opposite ends of the arch. Ties are usually deck and able to withstand the horizontal thrust force that would normally be given on arch bridge buffers.
Deck suspended from arch. The arch is in compression, unlike the suspension bridge where the catenary is in suspense. Bridges tied with archs can also be a curved bridge.
Gallery
Use of modern materials
Most modern arch bridges are made of reinforced concrete. This type of bridge is suitable where temporary concentration can be established to support form, reinforcement, and unforged concrete. When the concrete is fairly arranged the shape and falseworks are then removed. It is also possible to construct a reinforced concrete arch of precast concrete, in which the arch is constructed in two parts which then lean against each other.
Many modern bridges, made of steel or reinforced concrete, often hold their loads because of the tension within the structure. This reduces or eliminates the horizontal impulse to the abutment and allows their construction to weaker soil. Structurally and analytically they are not a true curvature but a beam with a curved shape. See the truss curved bridge for more about this type.
The modern evolution of the arch bridge is a long span through a curved bridge. This has been made possible by the use of lightweight materials that are strong in tension such as steel and prestressed concrete.
See also
Footnote
References
Boyd, Thomas D. (1978), "The Arch and Vault in Greek Architecture", American Journal of Archeology , 82 (1): 83-100 (91), doi: 10.2307/503797
External links
- NOVA Online - Super Bridge - Arch Bridge
- Matsuo Bridge Co. - Bridge Arch
- Historic Bridge in the Midwest
- Historic Railroad Bridge in Western Massachusetts
Source of the article : Wikipedia
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