According to Aleksey Baranov, Director of the OJSC USK MOST Branch in Vladivostok, a total of 41.4 thousand cubic meters of high grade concrete mix were placed in the legs of M6 and M7 Pylons. Installation of elevators and other equipment necessary to support operation of the unique structures is coming to a close inside the pylons.

The bridge builders have also removed the installation rigs, which traveled to meet each other in the middle of the strait while lifting the panels of the channel span main stiffening girder. The intensive work is going on here to finish the roadway: they are putting in place the railing, provide waterproofing, and install lights and electric equipment. The pillars and span structures are being painted.

Meanwhile installation of the monitoring system pickups and stay cable damping system continues, and the builders will have to conduct the final cable tensioning when the roadway asphalt concrete paving has been completed.

Photo by Igor Lischuk / SK MOST

The operation in the construction site water area was started at 9:00 p.m. local time on April 11, and the builders proceeded immediately with loading off Section Number 52 to “Grigorich” Pontoon, which was custom -equipped for the purpose. The lifting of the closing panel to the design elevation of 70 meters and completing of the joint within the channel span deck have lasted almost until 04:00 a.m., and all that time thousands of people have been watching this exciting process as it happened from vista points and volcanoes. Many residents of the capital city of Primorie Region just could not miss this significant historical event. Two 546-meter long cantilever sections have been closed by a “golden link” right over the middle of the Eastern Bosphorus Strait to connect Vladivostok to the Russky Island.

“Vladivostok residents have dreamed about a bridge that would connect the mainland to the Russky Island for many generations” underscored Aleksey Baranov, Director of the OJSC USK MOST Branch in Vladivostok. “These dreams have come true, and the world record breaker 1,104-meter long channel span has been closed by the “golden link” at the altitude of 70 meters of the Eastern Bosphorus Strait. From the engineering viewpoint, it would be safe to say that the construction project has been completed. We can see today the giant pylons rising up to the 324-meter elevation and the central span structure between them that weighs over 22,000 metric tons, which is suspended on 168 supercompact stay cables that are about 55 kilometers long. The most advanced technologies and design concepts have been used in the various phases of construction, which allowed us to expedite the execution of this unique construction project. They include the drilling of ultradeep boreholes from the water in the eastern Bosphorus Strait, the use of high-grade concrete for pylon erection, and installation of the main stiffening girder paired panels from the water. Implementation of this unique project demanded enormous efforts, emotional contribution and expertise of all of us. I dare say, on behalf of all bridge builders, that we are happy because not so often, once in the lifetime really, one could be honored to be able to participate in the building of such bridge. The most advanced and innovative concepts that have been accumulated in the practice of Russian and world bridge building have been put into practice here, in this particular project. The fact that Vladivostok has been linked to the Russky Island today and a giant tricolor, a symbol of the Russian Bridge, flying over the shores of the Eastern Bosphorus Strait is the major conclusion of this gigantic and crucial undertaking.”

According to Aleksey Baranov, Director of OJSC USK MOST Branch in Vladivostok, a serious preparatory phase preceded the today’s critical operation in the construction site water area. The stay cables on both sides of the strait have been adjusted, the joints have been trimmed to finish them, and the three closing panels underwent trial assembly on the building ways. This scale of preparations allows for high precision of installation at the 70-meter elevation.

The 12-meter long single end panels No. 51 weighing 170 metric tons have been lifted from the strait water to the design elevation on the Nazimov Peninsula side and on the Russky Island side. As a result, the total length of the opposed cantilever sections of the main steel stiffening girder is now 1092 meters or 98.9% of the total length. When the 12-meter gap has been closed, the world record breaker 1104-meter long channel span over the Eastern Bosphorus Strait will be completed.

The bridge builders will have to install the closing central key panel, panel No. 52, which will be lifted while being attached to two installation rigs on both sides to connect Vladivostok to the Russky Island.

Photo by Igor Lischuk / SK MOST

“In spite of a highly challenging conditions in the Eastern Bosphorus Strait, the lifting of paired panel number 49-50 on the Russky Island side has been completed normally,” commented Aleksandr Kishkin, SK MOST Rotation Shift Manager.” “A storm advisory was issued in Vladivostok on March 18th because of a strong wind. It is extremely dangerous for small-size vessels to navigate under storm conditions, which is why motor boats and ferry boats were prohibited from going to sea in any direction. However the strong wind subsided by Sunday evening and sea roughness calmed down. As soon as the decision was made to revoke the storm advisory, we have proceeded with the lifting of the 350-ton structure. Generally speaking, this is a normal thing in building the unique project under Primorie weather conditions where we have to squeeze into “windows” all the time to conduct installation. High expertise of our professionals and workforce and the teamwork interaction in the construction water area made an important contribution as well. The paired closing panel was lifted in the dark time; installation was started at about ten o’clock in the evening and has been completed by midnight.”

“After panel 49-50 has been lifted from the water on the Russky Island side, we have completed installation of paired sections of the channel span deck from the water,” added Aleksey Baranov, Director of the OJSC USK MOST Branch in Vladivostok. “The total length of the opposed cantilever sections of the main steel stiffening girder is now 1068 meters or 96.7% of the total length. To carry on the channel span closing process, we will have to install three final single panels, one on each side of the eastern Bosphorus Strait and the central closing panel, which will finally link Vladivostok to the Russky Island.

Photo by Igor Liwuk, Andrej Savin / SK MOST

It took about 240 cubic meters of concrete mix to concrete the closing section number 72, and a total quantity of high grade concrete in the body of the major bridge support is about 20.7 thousand cubic meters. After the pylon have risen to the elevation of 320 meters above the sea level, a cover and a top pyramidal structure have been built on top to impart the final architectural appearance to the pylon. The pinnacle of the giant support capped with the top structure is 324-meters high above the Eastern Bosphorus Strait water level.

The work on Pylon M7 is close to completion on the opposite side, on the Russky Island. The legs of the world bridge building record giant support have reached the elevation of 319.9 meters above the sea level and are now practically of the design height.

Photo by Igor Lischuk / SK MOST

The world longest stay cables are installed at the elevation of 317 meters at M6 Pylon and are attached to the 50th panel of the main steel stiffening girder, which has been extended over the distance of 534 meters toward the Russky Island. The white jackets of each stay cable contain 80 strands of high-tensile wire with the design strength of 1860 megapascals. For the sake of comparison, this strength is five times as high as the strength of steel of which the channel span deck stiffening girder is made. The ultracompact stay cable design was developed specifically for the bridge to the Russky Island by Freyssinet, the world leader in stay cable installation.

“The ultracompact stay cables of the bridge to the Russky Island are second to none in the world in terms of both the length and design. Installation of the unique stay cable system was started eight months ago, in July 2011, and the work is now close to completion, which is the result of cooperation and excellent meeting of minds of Russian and French professionals on the construction site,” says Aleksey Baranov, Director of the OJSC USK MOST Branch in Vladivostok. “The tensioning of the final 42nd pair of stay cables has been completed on the Nazimov Peninsula side. Today they started installation of the 40th stay cable pair with the cables that are 555.6-meters long. The total length of the stay cables that have been already installed on the bridge over the Bosphorus Strait is now over 51 kilometers.”

Photo by Igor Lischuk / SK MOST

After the last 71st sections have been concreted, M7 Pylon is higher than a 106-story skyscraper. Figuratively speaking, two Eiffel Towers rise now on the shores of the Eastern Bosphorus Strait after the main bridge supports on the Nazimov Peninsula and on the Russky Island have reached the 320-meter height as per design. It will take to finish one concrete pouring section to complete the pylon erection.

“The concreting of the main or “standard” sections that form the pylon body has been completed,” explains Aleksey Baranov, Director of the OJSC USK MOST Branch in Vladivostok. “The final phase of the work is to tie up the two pylon legs by means of reinforced concrete cross-pieces at the level of the 71st sections to impart stiffness to the entire structure. The legs will be then capped with concrete “lids” each about one meter thick, which will support a top pyramidal structure. This will be the closing 72nd section, whose function is to protect the pylon interior space from atmospheric factors and to impart the final architectural appearance to the major bridge support.”

The builders of the SK MOST Group of Companies have completed erection of the main structure of M7 Pylon within a world record breaking time, practically within two years. A total of 40 thousand cubic meters of high-grade concrete mix have been placed in the bodies of the giant supports on both sides of the strait.

Photo by Igor Lischuk / SK MOST

As a result of this operation, the assembled cantilevered part of the steel stiffening girder on the Nazimov Peninsula side extends now over a distance of 534 meters from the M6 Pylon centerline. On the Russky Island side where they conduct intensive preparations for lifting paired panel number 47-48 to the design elevation, a total of 486 meters of the span deck have been installed. The total length of the opposed cantilever sections of the main steel stiffening girder is now 1020 meters sharp or 92.4% of the total length of the 1104-meter long channel span of the bridge over the Eastern Bosphorus Strait.

Installation of the paired panels on the Nazimov Peninsula side has been completed. To close up the channel span deck, it will take5 lifts of paired and single sections including the closing panel number 52, which will be lifted by two installation units to tie together the two cantilevered parts of the main stiffening girder over the Eastern Bosphorus Strait.

Photo by Igor Lischuk / SK MOST

The pylons, installation units, and the main steel stiffening girder have 2 base reference stations, 6 meteorological stations and 24 global positioning receivers installed on them. The GLONASS and GPS receivers are streaming continuously the reference point positioning data to the Monitoring Control Center where the data is saved and where it is available for the analysis of the bridge health. The data from wind and temperature transmitters, which is also fed to the system, is used to include the wind and temperature effects on the bridge structures.

The geodetic equipment supplied by Leica Geosystems, Switzerland, and the meteorological stations from Vaisala, a Finnish company, monitor displacements of the bridge structures with an accuracy to a few millimeters at points where it is very hard if possible to use the conventional survey methods.

“The importance of installation of the satellite positioning receivers on the edges of the steel stiffening girder is hard to overestimate now. Because the central span deck structure is to be closed shortly, it has become critical for the bridge builders to monitor behavior of the cantilevered parts of the span structure on the Nazimov Peninsula side and on the Russky Island side for the nearest future,” underscores Aleksey Baranov, Director of the OJSC USK MOST Branch in Vladivostok.

“In order to do that, the transmitters will be repositioned from time to time to the next installed panels until the channel span deck is closed. After the bridge has been put in service, the integrated monitoring system will combine a structural health monitoring system, an automated traffic control system, and a security protection system.”

Photo by Igor Lischuk / SK MOST

“After the 71st concrete pouring cycle, we can say that the standard-size concreting sections forming the pylon body have been completed. The final phase is to tie up the two pylon legs by means of reinforce concrete cross-pieces at the level of the 71st sections to impart stiffness to the entire structure. The legs will be then capped with concrete “lids” each 80-cm thick, which will support 4.15-meter high tetrahedral pyramids made as the 72nd concreting sections. They will finish the architectural concept of the main bridge support. We are planning to complete the work by the end of February, and the total concrete volume will be 150 cubic meters,” commented Valery Medvedev, Chief Engineer, “Bosfor Department, NPO Mostovik.”M6 Pylon erection started in February 2010. Therefore, it took us exactly two years to reach the 320-meter height.”

Photo by Igor Lischuk / SK MOST