What type of bridge structure comprising one or more towers with the deck supported by wires from each tower, has two types, the harp and the fan? Notable examples are the Millau Viaduct, Second Severn Crossing and the elevated sections of the Oresund.
"a long cable-stayed bridge, which crosses the border marked by the River Wye between England and Wales, south of Chepstow. It consists of a single large cable stayed section with two single-leg pylons supporting the bridge deck from the centre of the roadway. The deck is an orthotropic box girder similar to the Severn Bridge but has a different appearance as it has two sets of cable stays on each of two towers. Originally there was only one set of cable stays but these were replaced during the strengthening works. The Wye Bridge was built by Cleveland Bridge & Engineering"
"four-lane highway on the upper level and a pair of railway tracks at the lower level. Tower Bridge in London is different example of a double-decked bridge, with the central section consisting of a low level bascule span and a high level footbridge. A viaduct is made up of multiple bridges connected into one longer structure. The longest and some of the highest bridges are viaducts, such as the Lake Pontchartrain Causeway and Millau Viaduct. A three-way bridge has three separate spans which meet near the center of the bridge. The bridge appears as a ""T"" or ""Y"" when viewed"
"from above. Three-way bridges are extremely rare. The Tridge, Margaret Bridge, and Zanesville Y-Bridge are examples. A bridge can be categorized by what it is designed to carry, such as trains, pedestrian or road traffic (road bridge), a pipeline or waterway for water transport or barge traffic. An aqueduct is a bridge that carries water, resembling a viaduct, which is a bridge that connects points of equal height. A road-rail bridge carries both road and rail traffic. Overway is a term for a bridge that separates incompatible intersecting traffic, especially road and rail. A bridge can carry overhead power lines"
"with sidewalks, with single lanes for cars flanking a large center lane for trains. The towers are . From east to west, the bridge consists of a long girder span, a long eastern truss approach span, the long central lift span, a long western approach span and four long girder spans. With the draw up, there is of vertical clearance above high water with a wide navigation channel between the timber pier fenders. Although the lift span weighs , the use of an equal amount of counterweights (located in each tower) means the span is operated with two relatively small"
"bicycle lanes, and sidewalks on its upper deck; and a pair of tracks for the Bloor–Danforth subway line on its lower deck. The western span of the San Francisco–Oakland Bay Bridge also has two levels. Robert Stephenson's High Level Bridge across the River Tyne in Newcastle upon Tyne, completed in 1849, is an early example of a double-decked bridge. The upper level carries a railway, and the lower level is used for road traffic. Other examples include Britannia Bridge over the Menai Strait and Craigavon Bridge in Derry, Northern Ireland. The Oresund Bridge between Copenhagen and Malmö consists of a"
"simple suspension bridges and suspended-deck suspension bridges, and excludes self-anchored suspension bridges. Some suspension bridges are of unusual hybrid types. Among these are suspension bridges that have an ""intermediate deck"". These bridges have a portion of deck that resembles an underspanned suspension bridge. Some of the earliest suspended-deck suspension bridges were of this type, and they continue to be constructed. Examples constructed in the 20th century include a viaduct over the river Oberargen near Wangen, Germany. A span of the viaduct has a cable support below the deck, with one end of the cable anchored at a pier and the"
"typically ranked by the length of their main span. These are the ten bridges with the longest spans, followed by the length of the span and the year the bridge opened for traffic: Suspension bridge A suspension bridge is a type of bridge in which the deck (the load-bearing portion) is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridges, which lack vertical suspenders, have a long history in many mountainous parts of the world. This type of bridge has cables suspended between towers,"
"standing on two legs. The bridge deck passes through the legs of the pylon, carrying two carriageways of two lanes each, as well as shared pedestrian and cycle ways on both sides. Fifty-six cables, arranged in two planes in a semi-fan configuration, support the -long main span, while another twenty-eight cables arranged in a single plane with a near-harp configuration connect the tower to the median of the anchor span. Most of the bridge, which is in length, is constructed of reinforced and prestressed concrete, except for the main span, which has a steel structure with a composite concrete deck."
"longest span between the two towers is . It is flanked by viaducts at both sides, which connect the bridge with the metro tunnels on the opposite banks of the Golden Horn. Nine cables are connected to each side of the two towers in harp-design starting at a height of . To restrain the soft bedrock, dozens of steel pipe piles with diameters of and , supplied from Europe, were driven using a hydraulic hammer more than deep into ground. The two steel supporting towers are high, Each resting on a nine-pile group while for the side supports four-pile or"
"particularly substantial anchor pylons for bracing the conductors of the crossing section, and two tall carrying masts to keep the line high over the water. These pylons have broader cross-bars and greater distances between the cross-bars than the other pylons of the line, in order to prevent the conductor cables from striking against each other during strong winds. In contrast to normal pylons, the two carrying masts at both ends of the crossing are frequently equipped with flight safety lamps, and have stairways for easy access to the top. Overhead line crossings of rivers and straits with spans of over"
"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 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"
"bridge and in which cables were in a combination of radial and semi-harp arrangement, in which cables are spaced apart on the pylon, like the harp design, but connect to one point or a number of closely spaced points on the deck. The dynamically shaped pylon consists of 2 inclined columns, which are rigidly connected to the driving lanes and bend mid-way. The upper portion of the pylon anchors the back-stay cables as well as the main-span cables and the self-weight of the pylon balances out the self-weight of the super structure through the eccentric location of its center of"
"types of suspension bridge. These include a stressed ribbon bridge, which is closely related to a simple suspension bridge but has a stiffened deck suitable for vehicle traffic. A very light bridge, constructed with cables under high tension, may approach a suspended deck bridge in the nearly horizontal grade of its deck. The bridge may be stiffened by the addition of cables that do not bear the primary structural or live loads and so may be relatively light. These also add stability in wind. An example is the bridge across the river Drac at Lac de Monteynard-Avignonet: this bridge has"
"3-span cable-stayed bridge, the loads from the main spans are normally anchored back near the end abutments by stays in the end spans. For more spans, this is not the case and the bridge structure is less stiff overall. This can create difficulties in both the design of the deck and the pylons. Examples of multiple-span structures in which this is the case include Ting Kau Bridge, where additional 'cross-bracing' stays are used to stabilise the pylons; Millau Viaduct and Mezcala Bridge, where twin-legged towers are used; and General Rafael Urdaneta Bridge, where very stiff multi-legged frame towers were adopted."
"with larger spans, typically lack sufficient horizontal and vertical clearance for large ships. See the Chesapeake Bay Bridge-Tunnel. The Millau Viaduct is a cable-stayed road-bridge that spans the valley of the river Tarn near Millau in southern France. Designed by the French bridge engineer Michel Virlogeux, in collaboration with architect Norman Robert Foster, it is the tallest vehicular bridge in the world, with one pier's summit at 343 metres (1,125 ft)—slightly taller than the Eiffel Tower and only 38 m (125 ft) shorter than the Empire State Building. It was formally dedicated on 14 December 2004 and opened to traffic"
"Twin bridges Twin bridges are a set of two bridges running parallel to each other. A pair of twin bridges is often referred to collectively as a twin-span or dual-span bridge. Bridges of this type are often created by building a new bridge parallel to an existing one in order to increase the traffic capacity of the crossing. While most twin-span bridges consist of two identical bridges, this is not always the case. The two bridges that form the Chesapeake Bay Bridge, for example, have several differences, most notably in the number of lanes each carries. The longest twin-span bridge"
"Transporter bridge A transporter bridge, also known as a ferry bridge or aerial transfer bridge, is a type of movable bridge that carries a segment of roadway across a river. The gondola is slung from a tall span by wires or a metal frame. The design has been used to cross navigable rivers or other bodies of water, where there is a requirement for ship traffic to be able to pass. This has been a rare type of bridge, with fewer than two dozen built. There are just twelve that continue to be used today, including one converted into a"
"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 a deck arch bridge. Any part supported from arch below may have spandrels that are closed or open. The Sydney Harbour Bridge is a through arch bridge which uses a truss type arch. Also known as a bowstring arch, this type of arch"
"carries rail traffic. One example of this is the Prince Edward Viaduct in Toronto, Ontario, Canada, that carries motor traffic on the top deck as Bloor Street, and metro as the Bloor-Danforth subway line on the lower deck, over the steep Don River valley. Others were built to span settled areas, crossing over roads beneath—the reason for many viaducts in London. Viaducts over water make use of islands or successive arches. They are often combined with other types of bridges or tunnels to cross navigable waters as viaduct sections, while less expensive to design and build than tunnels or bridges"
"type of bridge (a bowstring arch bridge): ""Spanning the river is the bridge’s arch structure with its ends carried by abutments on each bank. The deck of the bridge is suspended by struts attached to the arch and runs between the banks. Each end of the deck is connected to the arch’s legs."" If the main items mentioned are extracted and arranged in their order of mention in the text, this is what we get: ""River; Bridge; Arch; Ends of arch; Abutments; Banks; Deck; Bridge; Struts; Arch; Banks; Ends of deck; Arch legs"" It's obvious that the signs used to"
"Truss arch bridge A truss arch bridge combines the elements of the truss bridge and the arch bridge. The actual resolution of forces will depend upon the design. If no horizontal thrusting forces are generated this becomes an arch-shaped truss, essentially a bent beam – see moon bridge for an example. If horizontal thrust is generated but the apex of the arch is a pin joint, this is termed a three-hinged arch - see The Iron Bridge for an example. If no hinge exists at the apex, it will normally be a two-hinged arch. In the ""Iron Bridge"" shown below,"
"also sometimes called covered bridges. Early timber-framed covered bridges consisted of horizontal beams laid on top of piles driven into the riverbed below. However, this construction method meant that the length between bridge spans was limited by the maximum length of each beam. The development of the timber truss circumvented that limitation and allowed bridges to span greater distances than those with beam-only structures or arch structures, whether of stone, masonry, or timber. Early European truss bridges used king post and queen post configurations. Some early German bridges included diagonal panel bracing in trusses with parallel top and bottom chords."
"tower and bridge chapel, for example at the Krämerbrücke in Erfurt. The high cost of such towers was usually paid for by charging tolls. The gates of bridge towers were closed at night, so that no-one could cross the bridge during silent hours. Bridge tower A bridge tower () was a type of fortified tower built on a bridge. They were typically built in the period up to early modern times as part of a city or town wall or castle. There is usually a tower at both ends of the bridge. During the 19th century, a number of bridge"
"Symphony bridge A symphony bridge or bridge symphony is a bridge which combines the structural support systems of a suspension bridge, a cable-stayed bridge and a cantilever bridge. No such bridges have been built, nor are there any specific plans, although the method has been considered for several bridges in Norway. It was developed collaboratively by the Norwegian Public Roads Administration and the civil engineering consulting company Aas-Jakobsen as a means of building bridges with spans between . The design is based on two separate roadways which are connected by crossbeams. A symphony bridge would have two pylons, which would"
"Suspension bridge types A suspension bridge is any type of bridge that makes significant use of tension rather than or in addition to compression. A suspension bridge usually has main cables (else ropes or chains), anchored at each end of the bridge. Any load applied to the bridge is transformed into a tension in these main cables. The earliest suspension bridges had the cables anchored in the ground at either end of the bridge, but some modern suspension bridges anchor the cables to the ends of the bridge itself. The earliest suspension bridges had no towers or piers, but these"
"suspension bridge types, this type often is constructed without falsework. The suspension cables must be anchored at each end of the bridge, since any load applied to the bridge is transformed into a tension in these main cables. The main cables continue beyond the pillars to deck-level supports, and further continue to connections with anchors in the ground. The roadway is supported by vertical suspender cables or rods, called hangers. In some circumstances, the towers may sit on a bluff or canyon edge where the road may proceed directly to the main span, otherwise the bridge will usually have two"
"proportions or size of the arch: a large span will still require a tall arch, although this can now reach any height above the deck without obstructing traffic. The arch may also reach downwards at its sides, to either reach strong foundations or to place the roadway at a convenient height for spanning a deep valley from a plateau above. The Tyne Bridge demonstrates both of these advantages. A well-known example of this type is the Sydney Harbour Bridge in Australia, which is based on the Hell Gate Bridge in New York City. Other bridges include the Tyne Bridge of"
"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. Arch bridge An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side. A viaduct (a long bridge) may be made from a series of arches, although"
"are as follows: There are four major classes of rigging on cable-stayed bridges: ""mono"", ""harp"", ""fan,"" and ""star"". There are also four arrangements for support columns: ""single"", ""double"", ""portal"" and ""A-shaped"". Depending on the design, the columns may be vertical or angled or curved relative to the bridge deck. A side-spar cable-stayed bridge uses a central tower supported only on one side. This design allows the construction of a curved bridge. Far more radical in its structure, the Puente del Alamillo (1992) uses a single cantilever spar on one side of the span, with cables on one side only to"
"a lift bridge this type has only slight visual impact upon its surroundings when closed for use by road traffic. This is very well demonstrated by the ""Pont levant Notre Dame"" at Tournai in Belgium. Several rivers and waterways are home to multiple examples of table bridges. These include but are not limited to: Table bridge A table bridge is a moveable bridge in which the deck moves along the vertical axis. Hydraulic pillars under the bridge raise the bridge deck to allow barge traffic to pass beneath it. In contrast to a lift bridge, where the deck is pulled"
"The main span of the bridge consists of a reinforced concrete arch structure spanning between two concrete abutments located on the western and eastern sides of the river. The deck of the bridge consists of three main spans, the center span between the two abutments and the two approach spans up to the joint above the abutments. The reinforced concrete deck is supported by the arch by means of 12 sets three reinforced concrete columns or struts. The main arch structure was constructed in a unique fashion: the complete arch was divided into four semi-arches which were built with climbing"
"bridge at Osten is four years older and was the first transporter bridge in Germany. Transporter bridge A transporter bridge, also known as a ferry bridge or aerial transfer bridge, is a type of movable bridge that carries a segment of roadway across a river. The gondola is slung from a tall span by wires or a metal frame. The design has been used to cross navigable rivers or other bodies of water, where there is a requirement for ship traffic to be able to pass. This has been a rare type of bridge, with fewer than two dozen built."
"area between 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 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"