Cable-stayed bridge
A cable-stayed bridge is a bridge whose roadway carrier is suspended at an angle from a pylon tensioned cables.
- 3.1 precursor
- 3.2 Modern cable-stayed bridges 3.2.1 Examples of the further development
- 3.2.2 Inclined pylons
- 3.2.3 roadway support of concrete
- 3.2.4 roadway carrier made of steel and concrete composite
- 3.2.5 Combined cable-stayed bridges
- 3.2.6 Extradosed bridges
- 3.2.7 Mehrhüftige cable-stayed bridges
- 3.2.8 Largest cable-stayed bridges 3.2.8.1 The cable-stayed bridge with the largest span of their time
- 3.2.8.2 Other Records
- 3.2.8.3 Other examples
Function of the structure
The vertical loads on the tendons in the form of tension on the or headed the pylons and introduced by them in the form of pressure forces perpendicular to the ground. The horizontal force components arise on both sides in the direction of the pylon and are neutralized by the road carrier.
The required in true suspension bridge anchoring the horizontal force component of the supporting cable is not required. Cable-stayed bridges are thus more cost -effective than suspension bridges, reach so far but only about half as large spans ( in Russky Bridge and the Sutong Bridge about 1000 m). Up to 200 m span beam bridges are often more economical.
Like all suspension bridges are cable-stayed bridges in principle against wind forces sensitive and may be brought by large moving masses in motion. Point here, however, better properties than suspension bridges, so they are better suited eg as railway bridges.
For inspection of the supporting structure are rope bridge inspection equipment in use.
Variants
Rampant, mehrhüftige bridges
Cable-stayed bridges are usually rampant bridges with a pylon or zweihüftige bridge with two pylons.
However, there are also bridges with three pylons, as the Polcevera Viaduct in Genoa, bridges with four pylons as the Rio - Antirrio bridge at Patras in Greece, and the General Rafael Urdaneta Bridge over - the Lake Maracaibo with six pylons and the Viaduc de Millau in southern France, which in this respect has a leading position with its seven pylons. Mehrhüftige bridges have special requirements for the construction, since the moving load, for example, a truck has an impact on the support system of the adjacent pylon, which in turn can affect the next pylon.
Cable arrangement
The arrangement of the ropes can be done in Tufts, harps or fan system. When tufts system, the cables are all anchored in a knot. The pylon is thus subjected only to vertical normal forces. When harp system, the ropes have the same inclination due to the same high levels of traction, but the pylon additional horizontal forces must usually pay off. The fan system is approximately a combination of the other two systems. Initially, only a few were used strong ropes, but soon the trend was towards multi-cable system with many smaller ropes, as there is no cantilever easily possible and can be easily replaced.
Symmetric, asymmetric and tied back bridges
Most cable-stayed bridges are symmetrical, their cable arrangement is the same on both sides of the pylon. Apart from wind and traffic loads of both sides of the pylon equally long road carrier hangs in balance. In many bridges, however, is the part of the carrier via the main opening, and thus more difficult than that of the side opening. At this asymmetric bridges the difference in weight must be compensated, for example by the shorter part of the track carrier is carried out is stabilized by a heavier or serving as a tie rod or by abutment also serves as a tie rod supports ( cf. Fleher bridge). Some bridges have no side opening, the inclined cables carry only the floor beams above the main opening. For them, the pylons must be tied back with the help of anchor blocks in the ground (an example is the Carpineto Bridge ).
Pylon geometry
As a result of the cable anchorages pylons are stressed mainly by vertical pressure forces. However, caused by different forces in the ropes and bending moments.
With two cable planes between three basic types pylon can be distinguished. Self-supporting towers are soft deformation in the transverse direction and result in a higher sensitivity to vibration of the bridge. In contrast, A- pylons are very stiff in the transverse direction, whereby the bridge main girder can be made lighter. Although the H- pylons are softer than the A pylon, but the preparation thereof and the anchoring of the ropes on the pylon head is easier. The ropes are inclined only in one plane and the associated anchoring is spread over two pylon supporting.
With a rope level a means pylon is placed, usually a self-supporting tower. This type of construction, however, due to a heavy main bridge carrier, which is torsionally rigid in the transverse direction is formed.
Most pylons stand vertically. In -anchored bridges they are occasionally inclined away from the main opening to the anchor blocks as in the Ponte all'Indiano, in rare cases, from the main port as the Batman Bridge or the comparatively small Schenkendorfstraße bridge for a tram, pedestrians and cyclists.
While initially consisted mostly of steel pylons, often multicellular solid wall constructions with hollow cross sections, pylons large cable-stayed bridges are built almost exclusively of reinforced concrete. Contrast, prefabricated, round pylon rods are used in all situations in particular, pedestrian bridges, which results in the distribution of burdens and tensile forces so inclined, with irregular bracing rods are not uncommon.
Bridge deck
The bridge deck or roadway agencies listed in cable-stayed bridges and extenders carrier, regularly consists of aerodynamically shaped, flat steel box girders with an orthotropic plate. However, there are bridge decks from pre-stressed concrete box girders. The first and still largest example of this is designed by Riccardo Morandi General Rafael Urdaneta - bridge over the Lake Maracaibo. Occasionally, even combinations of steel girders in the main opening and concrete girders in the side opening, as in the Fleher bridge. Composite structures, in which the steel, the tensile forces and the concrete absorbs the pressure forces provide, theoretically, an obvious solution is, but are nevertheless remained rare.
History
Precursor
It is no longer possible to determine when the first inclined guyed bridges were built. From Africa was reported by bridges with inclined lianas stretched over the top Ogooué from Laos, Borneo and Java are bamboo bridges with some considerable spans known.
In Europe, the support system of the cable-stayed bridge was probably first shown by Fausto Veranzio printed in his 1616 work Machinae Novae. 1784 published Carl Emanuel Löscher a detailed description of a wooden cable-stayed bridge, which was built but probably not. Charles Stewart Drewry reported a 33.50 m long cable-stayed bridge, which was built in 1817 by James Redpath and John Brown of Edinburgh in Peebles at the King 's Meadow on the Tweed. The 1817 -built Dryburgh Bridge with oblique chains was destroyed a year later in a storm, breaking the further development in this direction.
Claude Navier in 1823 published a first basic treatise on suspension bridges, in which he also mentioned cable-stayed bridges, without bringing great confidence in this type of construction for expression.
The first bridge of this design in Germany was built by Gottfried band Hauer, the architect of the Duchy of Anhalt- Köthen and inaugurated in August 1825 Saalebrücke in Nienburg. She was in the middle of swung open to let ships with masts standing, and therefore consisted of two separate halves. Load-bearing members, therefore, only oblique chains came into question. At a festival in honor of the Duke on December 6, 1825, the bridge was loaded extremely one-sided and crashed due to vibrations through dancing people. In this accident 55 people were drowned in the river Saale.
John August Roebling built his bridges as mixed systems: the large suspension bridges have been reinforced by oblique ropes, so when Monongahelabrücke in Pittsburgh (1846), which was later replaced by the Smithfield Street Bridge, at the Niagara Falls Suspension Bridge (1854 ), the Cincinnati - Covington Bridge ( 1866) and finally the Brooklyn Bridge ( 1883).
Rowland Mason Ordish (1824-1886) had developed its own system, which he at the Franz Joseph Bridge ( 1868), an oblique chain bridge in Prague signs to remain and repeated at Albert Bridge ( 1872) in London without much success.
Ferdinand Arnodin also developed in its structural steel and wire company, a mixed system in which of the pylons first stay cables are tensioned to a track, and only in the middle one-third to two quarters of the tension field with hangers, is suspended from the supporting cables, so at the Pont de l' Abîme (1887 ) or the Pont Sidi M'Cid (1912 ) in Constantine (Algeria).
In the U.S., Edwin Elijah Runyon received a patent for a cable-stayed bridge, on the basis in the 1890s, two bridges were built in Texas.
Albert Gisclard developed in France in the late 19th century a system of crossing, to the other half of the bridge stay cables reaching. Many bridges were built according to this system, often by Ferdinand Arnodins company in which his son-in Gaston Le Cocq Leinenkugel supervised the construction work and later, the system Gisclard further developed. The most famous of Gisclards bridges is the railway bridge Pont de Cassagne (1908 ); after his death, the Viaduc des Rochers Noirs ( 1913) and the Puente Colgante de Santa Fe ( 1924) in Argentina was created. Leinenkugel Le Cocq led Gisclards further ideas and built the old suspension bridge Pont de Lézardrieux over the Trieux in Brittany in 1925 to a railway cable-stayed bridge. The so-called suspension bridge of Deir ez- Zor was probably the last bridge of this type.
Modern cable-stayed bridges
In Franz Dischinger 1949 published papers the theoretical foundations for the construction of modern cable-stayed bridges were laid. While previous bridges were criticized flaccid stay cables due to their higher voltages and thus more rigid bridges were now possible with ropes made of high- strength wires.
Whether Albert Caquot knew these publications can probably no longer be ascertained. Anyway, he built as part of the installation of the Canal de Donzère - Mondragon among other things, the Donzère - Mondragon cable-stayed bridge with a bridge deck and pylons of reinforced concrete. It was completed in 1952 along with the channel and was the first modern cable-stayed bridge. She had, however, possibly because of their small size and remote location, little influence on the further development of cable-stayed bridges.
In 1952 a group of engineers to Fritz Leonhardt the contract to design the north bridge in Dusseldorf, later Theodor Heuss Bridge. Leonhardt took Dischinger on suggestions and designed a cable-stayed bridge with a span of 260 meters and a total length of 914 meters and a steel bridge deck. The initially arranged in tufts form ropes he changed at the request of the architect Friedrich Tamms, head of the city planning department, in a harp -shaped cable system with parallel cables, the optical can not overlap even if obliquely.
Meanwhile, designed by Franz Dischinger and built by Demag Strömsundbrücke had been completed in Sweden in 1955. It has a main span of 182 meters and a total length of 332 meters and also a steel box girder. It is commonly referred to as the first major cable-stayed bridge in the world.
The Theodor Heuss Bridge was later built and completed in 1957. She was thus the first cable-stayed bridge in Germany. Tamms commissioned shortly after Fritz Leonhardt planning the Rheinkniebrücke and Hans Grassl with the Oberkasseler bridge. The three bridges were characterized by the same stylistic elements - a flat steely bridge deck, slim vertical pylons and a few, harp -shaped arranged inclined cables - and thus became the Düsseldorf bridge family, even if the Rheinkniebrücke until 1969 and the Oberkasseler bridge provisionally in 1973 and after her shift finally were first opened to traffic in 1976. They have influenced the development of cable-stayed bridges around the world for many years significantly.
The bridge type was spreading rapidly; its development has been driven primarily by the large-scale reconstruction needs in Germany. At Expo 58, he became known to the pavilions to a broad audience through the designed by Egon Eiermann and Sep Ruf web. In Cologne, the Severin Bridge was opened in 1959 with the first A-shaped pylon, whereby a particularly stiff bridge deck was reached. 1961 showed the Leonhardt Andra & Schiller on the web for the first time a slanting, deep-anchored in the ground pylon. In 1962, the North Elbe bridge or highway bridge Moorfleet by Hellmut Homberg as the first pure highway bridge was completed in Hamburg. In the years 1959-1962, designed by Riccardo Morandi bridge over Lake Maracaibo in Venezuela was built, the first of a long series of cable-stayed bridges with pylons and bridge deck concrete. In 1964 with the George Street Bridge, Newport, South Wales, the first modern cable-stayed bridge in the United Kingdom and the following year with the largely unnoticed Pont de Saint -Florent- le- Vieil the first steel in France. Helmut Homberg built with the Rhine bridge Leverkusen nor any of its hamburgers Noderelbebrücke similar highway bridge with only two harfenfömig arranged ropes on each side of the two central pylons.
The Friedrich- Ebert-Brücke (Bonn) in Bonn and also in 1967 completed Rhine bridge Rees- Kalkar, both also designed by Homberg, cable-stayed bridges emerged for the first time with a variety of ropes, which is only by the introduction of high-performance computer systems was possible.
Examples of the further development
Improvements in the methods of calculation and of the materials and the enormous increase of the performance of computer systems in a short time led to a diversification of cable-stayed bridges in a wide variety of types and variants. Thus, the Kurt -Schumacher- bridge ( 1972) between Mannheim and Ludwigshafen a high A -pylon with asymmetrical cable arrangement and the first ropes of parallel wire bundles. The Köhlbrandbrücke (1974 ) in the Port of Hamburg was their A- pylons whose stems include the track support, the model for a large number of similar or derived from their pylons. Raiffeisen Bridge ( 1978) over the Rhine in Neuwied has an A -pylon in longitudinal direction of the bridge, the Airport Bridge (2002 ) in the Rhine crossing Ilverich has in the form of standing on the top because of the nearby airport Dusseldorf pylons triangles. The Fleher Bridge ( 1979) over the Rhine in Dusseldorf has the highest pylon and 368 m, the longest span of cable-stayed bridges in Germany; also it combines a steel box girder in the main opening with a reinforced concrete box girder on the land facing side of the pylon. The stay cables of the Viaduct Obere Argen (1990 ) on the A96 near Wangen be continued under the floor beams as brownouts with three air supports. The Stork Bridge (1996 ) in Winterthur is the first bridge with cable-stays of carbon fiber reinforced plastic ( CFRP).
Inclined pylons
A number of bridges has inclined pylons because the outer inclined cables not attached to the track support, but are anchored in the ground. Examples are the Viadotto Ansa del Tevere (1967 ) in Rome, the Batman Bridge ( 1968) in Tasmania, which is also the oldest cable-stayed bridge in Australia, the New Danube Bridge ( 1972) in Bratislava with a tower restaurant on the pylon, the Carpineto Bridge ( 1977) in southern Italy, the Ponte all'Indiano (1978 ) in Florence, the Rhine bridge N4 (1995 ) at Schaffhausen and the Erasmus Bridge (1996 ) in Rotterdam.
A special feature is the Alamillo Bridge (1992 ) in Seville from Santiago Calatrava, in which the oblique pylon is a counterweight to the bridge superstructure.
For other bridges, the inclined pylons of the curved in plan roadway are due, as in the Abdoun Bridge ( 2006) in Amman, the only cable-stayed bridge in Jordan, or the Pont de Térénez (2011) in Brittany.
Floor beams made of concrete
Examples of cable-stayed bridges with road carriers of concrete are the bridge over the Wadi al - Kuf (1971 ), the Network Bridge West ( maximum ) ( 1972) on the Main, the first cable-stayed bridge for road and rail transport, the Puente General Manuel Belgrano ( Puente Chaco - Corrientes ) (1973 ) over the Río Paraná, the Puente Pumarejo (1974 ) in Barranquilla, Colombia, the Prince Willem- Alexander bridge (1974 ) over the Waal near Tiel in the Netherlands, the Brotonne Bridge (1977 ) the Seine, the Danube bridge Metten (1981 ) in Deggendorf, the Most Sloboda or ( liberty Bridge ) ( 1981) in Novi Sad, Serbia, the Sunshine Skyway bridge ( 1987) on the Tampa Bay, Florida, the Puente Ingeniero Carlos Fernández Casado (1983 ) about Barrios de Luna reservoir in northern Spain with a span of 440 m and the Skarnsund bridge ( 1991) in Norway with in this group is currently (2013 ) the largest span of 530 m. The comparatively small bridge over the Rhine Diepoldsau (1985 ) on the Alpine Rhine shows that cable-stayed bridges with road carriers from only a 55 cm thick concrete slab are possible.
Floor beams of steel and concrete composite
The first, however, only completed after a very long construction cable-stayed bridge with a roadway support made of a steel and concrete composite was the Second Hooghly Bridge (1972-1992) in Calcutta, followed by the two previously completed production bridges, the Ponte Edgar Cardoso (1982 ) in Figueira da Foz in Portugal and the Alex Fraser Bridge ( 1986) in Greater Vancouver, Canada. The Puente Río Mezcala (1993 ) in Mexico, the Second Severn Bridge ( 1996) at Bristol in England and the dreihüftige Ting Kau Bridge (1998) in Hong Kong are more examples. The Berlin Bridge ( 2006) in Halle ( Saale ) was the first composite bridge in Germany.
Combined cable-stayed bridges
If the available space is not sufficient for a zweihüftige cable-stayed bridge, or they would be too expensive under the circumstances, combining occasional one asymmetric cable bridge with the cantilever beams of a cantilever bridge, as in the already mentioned work bridge West ( High ) ( 1972), or Franjo Tuđman bridge ( 2002) in Dubrovnik.
Extradosed bridges
Some cable-stayed bridges are considered Extradosed bridges, such as the Cable-Stayed Bridge (1975 ) in Vienna and the Ganter (1980 ) as part of the Simplon pass road and the Sunnibergbrücke (1998) at the monastery, both of which were designed by Christian Menn, and also the high street Považska Bystrica (2010 ) with 7 pylons.
Mehrhüftige cable-stayed bridges
In mehrhüftigen cable-stayed bridges, the effects of moving loads are limited to the adjacent pylons through different measures. This can be seen for example in the General Rafael Urdaneta Bridge ( 1962) over Lake Maracaibo in Venezuela, the Polcevera Viaduct ( 1967) in Genoa, the Ting Kau Bridge (1998), Hong Kong with four wire planes, the Puente Orinoquia ( 2006) on the Orinoco and in the Rio Antirrio bridge (2004) in Greece, which is the second longest cable-stayed bridge in the world with 4 pylons and a length of 2252 m, and the Viaduc de Millau (2004) in France, the longest with 7 pylons and 2460 m cable-stayed bridge in the world.
Largest cable-stayed bridges
The cable-stayed bridge with the largest span of their time
Other Records
The Öresund Bridge (2000) between Denmark and Sweden is the longest cable-stayed bridge for combined road and rail transport. The widest is the Leonard P. Zakim Bunker Hill Memorial Bridge (2002) in Boston, USA, with ten lanes and 56 meters wide. The Suez Canal Bridge (2001), with a clear height of 70 m the highest, built in flat land cable-stayed bridge in the world and the Baluarte Bridge ( 2012) in Mexico is with 402.5 meters above the valley floor, the highest cable-stayed bridge in the world.
Leonard P. Zakim Bunker Hill Memorial Bridge
Suez Canal Bridge
Baluarte Bridge
Other examples
Alamillo Bridge in Seville
Bridge over the Rhine at Schaffhausen N4
Ponte Vasco da Gama in Lisbon
Sutong bridge over the Yangtze River