Инновационные технологии применяемые в строительстве разводных мостов
Кочеткова Алена Алексеевна
студент, МГСУ, kochetkova.alena2003@yandex.ru
Ушанова Надежда Петровна,
старший преподаватель, кафедра ИЯ и ПК, НИУ МГСУ, nadezhdaushanova@gmail.com
Строительство моста - это долгий вдумчивый и затратный процесс. Несмотря на все достижения современной науки и техники, остается еще много места для изобретений и достижений. Можно только предполагать, какие удивительные конструкции и механизмы появятся в будущем. В статье рассматриваются основные технологии, применяемые при строительстве раздвижных мостов. Для того, чтобы понимать главные тенденции в современном мостостроении, в тексте проанализированы история раздвижных мостов и строение некоторых важнейших образцов. При помощи научных и публицистических статей были описаны механизмы их работы. Ключевые слова: раздвижные мосты, история раздвижных мостов, наклонный мост, сворачивающийся мост, разводные мосты, складной мост, поворотный мост.
The developments of technologies in the field of engineering have found an application in bridges structure. Due to innovations, it became possible to efficiently meet the needs of a city: to erect diverse constructions in various restrictive areas and applying resources more rationally.
Movable bridge is a bridge with a lifting or rotating segment. This bridge type is useful on navigable rivers amidst dense urban environments where it is not possible to separate shipping lanes and ground transport or pedestrian paths in a different way. The application of movable bridges allows to fit such a construction into the level of adjoining streets and to save on costly supports and embankments of entrances.
The movable bridge constraction is originated in medieval Europe with inventions of bascule and drawbridges. The earliest of them appeared in Northern Europe, probably in Normandy, as a means of defence for towns and castles.
The first known example of movable bridge is The Old London Bridge (pict. 1), built in the beginning of the 13th century. It was a 282 m long stone bridge with many multistory (up to seven stories high) buildings on it: residentials, shops, chapels, etc. In the center it had a wooden drawbridge to allow the passage of vessels with masts too high to go under the arches of the bridge.
Pict. 1. The Old London Bridge.
Subsequent technical development and the beginning of canal construction has led to the invention of new type of bridge. Although swing bridges became more common by the late 18th century, their first design was created by Leonardo da Vinci in about 1500. The actual first swing bridge was designed and built by French engineer Salomon de Caux in 1625 in Cherbourg, France. It consisted of two spans revolving on iron bearings supported by balance wheels rolling on circular tracks.
The main material applied for the building of early swing bridges was cast iron. Due to its brittleness passing ships damaged the deck of the bridge; also the width of the passage was limited to about 13 m. The introduction of steam power and following enlargement of vessels and weightening of trains created a need for bigger and more
durable bridges. To achieve this, wrought iron and steel were applied since the mid-19th century.
The appearance of Scherzer bridges in the late 19th century was due the development of steel rolling technology. William Donald Scherzer was an American engineer who designed the refined bascule bridge - the rolling lift bridge. The first of his bridges, Van Buren Street Bridge, was built in Chicago in 1895. This bridge type represents a hinged structure with a massive counterweight. The invention of Scherzer was recognized as the most useful mechanism of the generation. Many of them are built in USA and some in France and India.
Engineering developments of the 20th century has contributed to the occurrence of many types of movable bridges: folding, curling, table, tilt, vertical-lifting bridge, etc. In the following reviewed some of them.
Tilt Bridge is a type of movable bridge with a deck which rotates about its endpoints. The most famous tilting bridge is Gateshead Millenium Bridge (pict. 2), the first of its kind in the world, located in Gateshead, UK; designed by WilkinsonEyre in 2001. It is composed of two steel parabolic arches. The distance between them is 100 m and the length of the deck is 126 m.
Pict. 2. Gateshead Millenium Bridge tilting.
The bridge works through the electricity generated by hydraulic system integrated into the balustrade. A bank of six hydraulic rams connects to a steel paddle and thrusts against it to rotate arches by a total of 40°. For this mechanism to work the construction must have been as lightweight as possible - that is why two arches are lighter towards the center of the parabola than at the hinges. For reliability, 18 suspension cables join the arches together.
The deck of a bridge is divided into footway and cycleway. The interesting feature of the construction is that it cleans its own litter - when the deck lifts, everything rolls to the special traps arranged at each end of the bridge.
Other examples of tilt bridges are Scheepsdalebrug and Sint-Annabrug built in 2011 in Belgium.
The Rolling Bridge is a pedestrian steel bridge located in London, UK built in 2005. The designer of this bridge, Thomas Heatherwick, was inspired by motions of animatronic Jurassic dinosaurs' tails.
The structure consists of eight segments on hinges, each in the shape of an isosceles trapezoid. One of the platforms is attached to the bank and the other seven are not fixated. The bridge is moving due to the hydraulic cylinders - the mechanism is composed of motor and RRR dyads. When it is required, cylinder rods move out, pulling together the platforms and curling the bridge (pict. 3).
Pict. 3. The process of folding of the Rolling Bridge.
Moved by the hydraulic liquid, the Rolling Bridge is very quiet. It curls up in about three minutes and can be stopped at any point. In folded position the bridge represents an octagon.
The Rolling Bridge is the only bridge of its type in the world.
Bascule bridge is a type of drawbridge with spans pivoting on the horizontal axis, balanced by a counterweight or a shorter backspan or both.
A prominent example of a bascule bridge is standing over river Clwyd in the city of Rhyl, UK. The Pont-y-Ddraig Harbour pedestrian and cyclist Bridge designed by Gifford (now part of Ramboll) and built in 2013.
It is not a typical bascule bridge - its decks' rotation axes are not located at the ends but in the center. The decks are composed of polymers reinforced with glass fiber; they are hinged to the central caisson. The cables that raise the decks are running to the 48 m high central must sitting over the caisson. To ensure safety and longevity of the bridge wire infill is installed in both sides. One interesting feature of the bridge is that its decks can be operated separately, lifting or lowering one side at a time. The Pont-y-Ddraig Harbour Bridge is a great place of attraction - besides being an engineering wonder, it also glows with different colors at night (pict. 4).
Pict. 4. The Pont-y-Ddraig Harbour Bridge glowing.
Although there are many drawbridges in the world, the design of The Pont-y-Ddraig Harbour Bridge is extraordinary.
The Hörn Bridge (pict. 5) is a pedestrian and cyclist bridge in the city of Kiel in Germany. It was designed by Gerkan, Marg & Partners and built in 1997.
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Pict. 5. The Hörn Bridge folding.
It is made of girder grids with rolled steel profiles; initially wooden deck was renewed with non-slip synthetic coating in 2012. The bridge has a built-in illumination system. It is formed by three segments, which fold in the shape of the letter "N". The drive system of the bridge is transparent. Two cables are attached to the each side of the deck; they are deviated via two mast portals that are fastened on hinges in the foundation of the bridge. This way, when masts tilt back the cables pull closer segments of the deck.
At first Kielians were skeptical of the design of the bridge. It got the name "Klappt-Nix-Brücke" (Folds-not Bridge) because of repeated malfunctions upon startup. The backup hydraulically operated retractable bridge was built near the Hörn Bridge to ensure crossing for citizens. It is still used during repair of the main bridge.
The Scale Lane Bridge (pict. 6) is a pedestrian and cycle bridge lockated in Hull, UK. The architects McDowell+Benedetti desiged a noteworthy apostrophe-shaped swing bridge.
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Pict. 6. The Scale Lane Bridge.
There is a strong reason for the material choice: the steel sheets retain internal strength outlining the wide curves of the bridge. The deck is beam structured: it has a box cross section with spacers for additional firmness. The lower part of the bridge is bended to permit the passage of smaller vessels.
The movement of the bridge is powered by three electric bevel gears. The bridge is cantilever, it rotates around the cenral slew bearing secured to a concrete drum.
It is the first bridge in the world where people can stay "on board" during the operation. The slow movement of the bridge allows pedestrians to walk on and off the bridge anytime through the anchored west side of it. When the bridge opens for the river traffic to pass, the installation of artist Nayan Kulkarni activates. The tinkling bells and flashing lights serve not only the artistic purposes, but also they alarm pedestrians about the beginning of rotation. Being onto the Scale Lane Bridge you can visit the restaurant or the viewing platform located right on the deck. Low-level fluorescents integrated into the parapet posts highlight the profile of the bridge at night.
Generally, bridge construction is long thoughtful and costly process. In spite of all the accomplishments of modern science and engineering there is still plenty of space for inventions and advancement. One can only assume what amazing structures and mechanisms would appear in the future.
Innovative technologies applied in movable bridge construction Kochetkova A. A., Ushanova N.P.
National Research Moscow State University of Civil Engineering JEL classification: L61, L74, R53
In general, the construction of a bridge is a long thoughtful and costly process. Despite all the achievements of modern science and technology, there is still a lot of room for inventions and achievements. One can only imagine what amazing designs and mechanisms will appear in the future. The article deals with general technologies applied in movable bridges' construction. In order to understand the main tendencies in modern bridge engineering the history of movable bridges and the structure of some major examples were analyzed. Using scientific and journalistic articles the working mechanisms of bridges were described. Keywords: movable bridge, history of movable bridges, types of movable bridges, tilt bridge, rolling bridge, bascule bridge, folding bridge, swing bridge. References
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6. "The Rolling Bridge." stroyone.com, 15 October 2022, stroyone.com/bridge/moveable-bridge/the-rolling-bridge.html. Accessed 27 October 2022.
7. Pont Y Ddraig, Rhyl - History Points. historypoints.org/index.php?page=pont-y-ddraig-rhyl. Accessed 27 October 2022.
8. "Three-Segment Folding Bridge Kieler Hörn." Sbp, 2 August 2022, www.sbp.de/en/project/three-segment-folding-bridge-kieler-hoern. Accessed 27 October 2022.
9. "Hörn Bridge." stroyone.com, 15 October 2022, stroyone.com/bridge/moveable-bridge/horn-bridge.html. Accessed 27 October 2022.
10. Schumacher, Michael. "Scale Lane Bridge." De Gruyter, 16 Dec. 2019, www.degruyter.com/document/doi/10.1515/9783035613629-033/html?lang=de.
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