- Historical reference
- Technical parameters of the project
- Features of the construction of pylons
- Construction of cable-stayed bridge system
- Installation of the central span
- Among the record holders, but not the main winner
In the Far East in the spring of this year, the construction of one of the world’s largest cable-stayed bridges was completed. The new bridge crosses the Eastern Bosphorus Strait and connects the mainland with the Russky Island. In April 2012, the builders completed the welding of a 1104-meter channel span.
This is the first bridge of this size and construction in Russia. It can rightfully be called a unique achievement of Russian engineers, since the bridge has become a champion in several indicators at once: the longest cable-stayed span in the world (1104 m), the longest cables (580 m). In addition, it took the second highest in the world, its pylons reach a height of 320 m.The total length of the structure is 3100 m, and the height of the main track is 70 m above the ground, which allows even the most bulky ocean liners to pass under it.
The authorities of the USSR in the first half of the 20th century were planning to build a bridge that would connect the Russky Island with the mainland. For the first time they started talking about it in 1939, when the first project of the bridge was proposed. But then, due to the outbreak of the Great Patriotic War, things never came to fruition. Later, in the 1960s, a second attempt was made, but the second project was never implemented..
However, what was not done then was finally realized in the 21st century. In 2007, a tender was held to develop a project for a modern bridge to Russky Island, which was won by the NGO Mostovik.
Together with the largest design organization in Russia, CJSC Institute Giprostroymost St. Petersburg, the production association has started development. Several small Russian and foreign scientific companies also worked on the project, including: Cowi A / S (Denmark), Primortisiz, Primorgrazhdanproekt, NPO Gidroteks, Far Eastern Research Institute Morflot and some others.
In the process of developing the project, the experts considered more than 10 very different options, among which were projects of both classical suspension and cable-stayed bridges. As a result, preference was given to the construction of the cable-stayed bridge. The design was completed in March 2008 and cost the state 643 million rubles.
The construction of a cable-stayed bridge across the Eastern Bosphorus Strait to Russky Island started on September 3, 2008 in preparation for the APEC international summit, which will be held in Vladivostok in 2012. The construction of the facility was completed in the spring of 2012.
On June 22, 2012, full-scale dynamic tests of the structure were completed, which confirmed its reliability and full readiness for operation..
The construction of the bridge proceeded under rather difficult conditions. The work was complicated by the unfavorable temperature regime and strong winds. Temperature drops in Vladivostok can range from -31 ° C to + 36 ° C, the height of the storm wave can reach 6 m, and the thickness of the ice cover is 70 cm.
In total, for almost 4 years that the construction lasted, 33.9 billion rubles of budget money were spent on the implementation of this project. But it was worth it.
Technical parameters of the project
The design of the bridge across the eastern Bosphorus was developed by engineers taking into account two determining factors:
- The shortest distance along the water area at the intersection of the bridge crossing is 1460 meters, and the depth of the fairway reaches 50 meters.
- Strong wind load in the construction area, as well as a wide range of temperature differences.
Main technical parameters of the new bridge across the Eastern Bosphorus:
- Central span length – 1104 meters;
- The shortest guy – 135.771 meters;
- The longest guy – 579.83 meters;
- The height of the pylons is 320.9 meters;
- The height of the bridge space – 70 meters.
- The total length of the bridge is 1885.53 meters;
- The total length of the bridge with overpasses is 3100 meters;
- 4 lanes (2 in each direction);
- The total width of the carriageway is 21 meters.
I would like to note that this is a truly ambitious project. For example, for the construction of anchor spans of a bridge to a height of seventy meters, more than 21 thousand cubic meters of concrete mixture were supplied, and the total amount of reinforcement of the side spans was about 10 thousand tons.
Features of the construction of pylons
For the bridge to be strong and reliable, 120 bored piles were installed under each of the two 320-meter pylons. The pylons were concreted using a unique self-climbing formwork with 4.5 m grips.According to the engineers, a crane was used for the first three grips, then the formwork moved up independently thanks to the hydraulic movement of special modular elements.
At the base of each pylon there are 120 bored piles with a diameter of two meters
Note that the technology with the use of self-climbing formwork allowed not only to improve the quality of construction work, but also to reduce the construction time of the bridge by 1.5 times. Since the pylons of the bridge are A-shaped, it was not possible to use standard formwork. As a result, a separate set was specially mounted for each pylon..
The construction of the foundation for the M7 pylon was carried out without an embankment. All drilling operations were carried out in water at depth. Note that the depth of the water area in this area is from 14 to 20 m. Steel casing pipes were submerged under the water using a special floating crane. After the construction of the bored piles, the pylon foundation was strengthened with a grouting layer of concrete up to 2.5 m thick.
For the construction of each pylon grillage, it took about 20,000 cubic meters of concrete and about 3,000 tons of metal structures
Everything was done in strict accordance with technology to ensure the strength and stability of the pylons.
Construction of cable-stayed bridge system
The cable-stayed system is, without exaggeration, the basis of the bridge. It is she who takes on the main static and dynamic loads, without it the existence of the bridge is simply impossible. For the bridge to be strong, the cables must be protected as much as possible from the effects of natural disasters and other adverse factors..
The massive structure of the bridge across the Vostochny Bosvor Strait is supported by 168 cables from 135 to 579 m long.
During the construction of the bridge, cables made by the French company Freyssinet were used. As the manufacturers note, all cables were made at factories that passed the strictest selection and received the approval of Freyssinet specialists..
They have the highest indicators of endurance, strength, corrosion resistance, which, according to experts, provided an estimated service life of at least 100 years. The structure is capable of withstanding a breaking load of 1850 MPa.
An improved “compact” PSS system was used to fix the central span of the bridge structure, with a tighter placement of strands in the shell. Due to the fact that the compact configuration of the cables has a shell of a smaller diameter, it was possible to reduce the wind load on the bridge by 25-30%. In addition, this technology has reduced by a third the cost of materials for the construction of foundations, stiffening beams and pylons..
The cables consist of parallel strands, individually protected against corrosion, the number of which varies from 13 to 85
Its strength depends on how strong the protective shell of the cable is. For the new bridge, a high-density polyethylene shell was used, which has the following extremely important properties:
- resistance to temperature from -40 ° С to + 40 ° С;
- resistance to the negative effects of solar ultraviolet rays.
The PSS cables include parallel strands with a diameter of 15.7 mm, each of which includes 7 galvanized wires. In total, each cable has from 13 to 85 strands (strands).
In addition, the installed cables have a vibration damping (damping) system that allows them to stabilize the structure in strong winds.
The fastening of the cables to the pylons was carried out after strengthening the foundation and was carried out at a height of 189 m.There was also used modern technology, which made it possible to significantly speed up the construction – the concreting of the pylon body and the installation of cable-stayed pairs were carried out simultaneously.
Installation of the central span
There are currently only three cable-stayed bridges in the world with a span of more than 1000 meters. In addition to the Far East Bridge, this list also includes: the Sutong Bridge in China (span length 1080 m) and the Stone Cutters Bridge in Hong Kong (1018 m).
The bridge to Russky Island, thanks to the world’s longest cable-stayed span of 1104 meters, has already become a record holder and entered the history of world bridge construction. Of course, this was quite difficult to do, since the strong wind in this area puts a lot of stress on the frame and the span itself. The engineers managed to develop a special superstructure with a special aerodynamic section, which allows to reduce the load from squally wind.
The central stiffener is a single, all-metal box with an upper and lower plate, as well as a system of cross beams and diaphragms. Note that the total weight of the structure of the central bridge span was about 23 thousand tons..
In order to determine the optimal configuration of the section, at the stage of detailed design, additional aerodynamic calculations were performed, which were then optimized as part of the processing of a large-scale experimental model.
Installation of the central span required precision and quality from the builders. High-strength assembly joints were used to join vertical block walls, cross beams, longitudinal ribs and diaphragms.
The panels were delivered to the installation site by barges and then lifted by crane to a height of 70 meters
The large-scale sections necessary for the installation of the central superstructure of the bridge were delivered to the assembly site on barges and then lifted by a tower crane to a height of 76 meters, where multi-ton elements were interconnected and cables were attached to them.
Among the record holders, but not the main winner
Our bridge is rightfully topped the list of cable-stayed bridges with the longest cable-stayed span. Russian specialists managed to build an impressive structure, but we have not yet succeeded in becoming the leader in length and height among bridges of a similar type..
The longest cable-stayed bridge in the world is still in China. The length of the Hangzhou Bay Bridge in the East China Sea is about 36 km, which is almost 18 times longer than the new Far East Bridge. Its construction cost the PRC $ 1.4 billion.
The longest bridge in the world Hangzhou Bay
This bridge connects Shanghai and the small town of Ningbo in Zhejiang province. It was built for almost 4 years, traffic on it was opened on May 1, 2008. The bridge is quite wide, 6 lanes of 3 in each direction.
The bridge is located in an area with difficult climatic conditions, with frequent typhoons, storms and squally winds. Because of this, the bridge structure was specially strengthened and a special composition of concrete and steel was used for construction, which is resistant to typhoons..
Hangzhou Bridge has a special shape: it is built in the shape of the letter “S”. As the main reason for choosing such an unusual design, engineers say the desire to make the bridge as resistant as possible to strong tidal waves.
The highest cable-stayed bridge in the world is the Millau viaduct, which is built at an altitude of 270 meters. This amazingly beautiful structure is located in the south of France and connects Paris with Barcelona, passing through a wide gorge over the Tarn River.
Viaduct Millau (le Viaduc de Millau) – cable-stayed road bridge that crosses the Tarn river valley near the city of Millau in southern France
The Viaduct Millau bridge was opened to cars in December 2004, and its construction cost private investors almost 400 million euros.
The bridge has 7 cable-stayed columns, which are located at a distance of 350 meters from each other. The height of the structure (the highest pillar) is 343 meters, and the length is almost 2.5 kilometers.
The President in one of his interviews called the bridge to the Russky Island “a new symbol of Russia.” It’s hard to disagree with him. Our engineers have a lot to be proud of. The new cable-stayed bridge built in Vladivostok is not just a modern engineering structure, it is a large-scale achievement of domestic scientists and builders.
By building this bridge, Russia actually proved to the entire world community that it can independently implement large and complex projects from an engineering point of view. After all, all stages of the project from the design stage to construction were completely carried out by the forces of Russian specialists..
The commissioning of this bridge is also important from an economic and social point of view. Since it opens up new opportunities for the development of both Vladivostok and the entire Far Eastern region.
I would like to hope that this is not the last project of this scale for Russia..