An operation to install the railway arch of the Crimean bridge is underway in the Kerch Strait
The first stage of the maritime operation for the transportation and installation of the arches of the Crimean Bridge is underway in the Kerch Strait: a railway arch span weighing more than 6 thousand tons was delivered to the builders, and now they are preparing to lift it onto the fairway supports. More than a hundred specialists are involved in this most complex technological operation - sailors, specialized engineers, employees of research institutes and ordinary bridge builders.
“The maritime operation in the Crimean Bridge project is, without exaggeration, unique for bridge construction: it is transportation, and then lifting and installation in a sea area with an unstable hydrometeorological background of an arched structure whose weight exceeds 6 thousand tons. However, such an operation would have been impossible without the enormous experience accumulated by bridge workers in other projects. So our maritime operation is the result of many years of practice and advanced technologies of domestic and global bridge construction,” said Leonid Ryzhenkin, Deputy General Director for Infrastructure Projects of STROYGAZMONTAZH LLC.
Installation of an arched span in design position consists of several key actions. Before each start, quality control services, architectural supervision and construction control carry out an inspection of work already completed: they check for compliance technical documentation and confirm with the appropriate acceptance certificate.
On the eve of going to sea, the builders prepared the arch for loading onto floating supports. Two floating piers were installed under it, and, having received confirmation of a favorable weather forecast for the next three days, the builders loaded the arched span onto them. On the night of August 28, the floating system began its 5-kilometer journey from the Kerch shore to the bridge site. More than 10 tugs, boats and other vessels took part in this part of the operation - the direct sea part. The team of the operation itself is more than 100 people.
Early in the morning of August 28, the sailors brought the floating system into the alignment between the fairway supports with a maximum gap of up to 65 cm and secured it with anchor cables. At this point, the lifting equipment on the supports is completely ready: lifting units, working platforms, devices (cable jacks, pumping stations and so on).
At both edges of the arched span, “strands” of high-strength cables are secured, stretched to the arch from 16 jacks installed on top of the fairway supports. Each of the “strands” contains more than 40 cables, that is, the arch will be raised to a height using almost 700 cables. The lifting capacity of each jack is 650 tons, so, despite the weight of the arch being 6,000 tons, the builders provided a 40 percent reserve for lifting mechanisms.
During the day, the arch will begin to rise to its design height at an average speed of 5 meters per hour. By the time this operation is completed, the maximum permissible deviations of the structure along the bridge axis will not exceed 60 mm, and across the bridge axis - 30 mm. Then the arch will be secured with wind ties to the crossbars of the fairway supports.
In total, the installation of a railway arch on the fairway will not exceed 72 hours. At this time, navigation in the Kerch-Yenikalsky Canal is limited. As soon as the builders confirm the reliability of fixing the arched span at the designed height, navigation of ships along the fairway will resume as usual.
The final installation of the railway arch on the fairway supports will require about another month. Construction and installation work will be carried out from working platforms installed on fairway supports and will not affect navigation in the Kerch-Yenikalsky Canal.
The second stage of the naval operation - the installation of the road arch of the Crimean Bridge - is scheduled for September.
Reference
The length of the navigable span of the Crimean Bridge is 227 meters, the total weight of the structures of both arches is about 11 thousand tons. The under-bridge clearance, 185 meters wide and 35 meters high, ensures unhindered passage of all ships plying through the Kerch-Yenikalsky Canal.
A railway arch is a combination of a span with through main trusses and an arch. The trains move along the elements of the truss, while the arch, in conditions of such a long span, performs a supporting function. The truss and arch elements are connected by pendants.
Floating system – These are floating supports with an arched span submerged and fixed on them. It is based on pontoons, united like a catamaran and equipped with specialized deck equipment.
A video has appeared on the Internet showing how bridge builders raised the railway arched span of the Crimean Bridge onto fairway supports - to a height of 35 meters from sea level. This was reported by the information center of the Crimean Bridge project.
The process of lifting the arch, weighing more than 6 thousand tons, to the designed height took about 12 hours. The structure will be secured throughout the day.
“The ascent went as usual. We walked more slowly up to the 10-meter mark, did a lot of control tests, and carried out geodetic monitoring of the condition of the structure. Then the main ascent began. The arch was raised slightly above the design height for subsequent lowering onto the supporting parts. Over the next 24 hours, the structure will be equipped with wind braces - these are devices that secure the arch,” said the deputy production director of Mostootryad-1.
To install the overall structure, “strands” of high-strength cables were secured along both edges of the arched span, stretched to the arch from 16 jacks installed at the top of the fairway supports. The arch was raised on 700 cables using powerful jacks attached to supports. The lifting capacity of each jack is 650 tons, so, despite the weight of the arch being 6 thousand tons, the builders provided a 40 percent reserve for lifting mechanisms,” said the Crimean Bridge Information Center. The jacks were loaded gradually. The initial load of 5 tons was increased to 100 tons. The structure rose without deviation, within the alignment between two supports.
After the arch was “severed” from the floating system by one meter, it was kept suspended for an hour. During this time, specialists once again checked the reliability of all mechanisms and only then continued the ascent.
The floating supports, with the help of which the arch was towed, returned to the Kerch shore. They will be rechecked and re-equipped, after which the second arched span - the road one - will be transported and installed in the same sequence. As a result, two arched spans will rise above the fairway, under which ships will pass unhindered. Over the next month, builders will install the end elements of the arch and also unwind it - lowering it onto special supporting parts.
Installing the arches of the Crimean Bridge into the designed position is a unique technological operation.
For the first time in the history of domestic bridge construction, transportation, positioning in sea conditions and installation from the water onto the supports of a large navigation span are being carried out.
The maritime operation is carried out in conditions of limited shipping with a time window of 72 hours. In general, the operation brought together hundreds of specialists - sailors, specialized engineers, employees of research institutes and ordinary bridge builders.
During the operation, navigation along the Kerch-Yenikalsky Canal was limited. The ban did not apply to ships and vessels of the Navy, as well as federal bodies security. Vessel traffic will resume as normal. The final installation of the arch on the fairway supports will take about another month.
The arched span of the railway part of the Crimean Bridge is a combination of a span with through main trusses and an arch. The trains move along the elements of the truss, while the arch, in conditions of such a long span, performs a supporting function. The truss and arch elements are connected by pendants. Span length - 227 m. Height at the highest point - 45 m. Width along the axes of the arches - 20 m at the end, 5 m at the castle (highest point). Train traffic is provided on two tracks. The design includes inspection passages, cable-supporting systems, drainage trays, lightning protection and grounding, a monitoring system for engineering structures, air navigation and ship alarms, a centralization and interlocking system, communications and lighting poles, and architectural lighting.
The total cost of the Kerch Bridge will be 227.92 billion rubles in prices of the corresponding years. The bridge will be the longest in Russia; it will connect the Crimean Peninsula with the mainland of the Russian Federation by road and railway.
The capacity of the four-lane highway will be 40 thousand cars per day, Railway will include two paths with throughput 47 pairs of trains per day. Car traffic on the bridge should open in December 2018, train traffic on December 1, 2019. More than 200 major pieces of equipment, more than 20 units of watercraft and more than 5 thousand people are used at the facility every day.
The Kerch Bridge is one of the largest bridges in Russia. Its length is 19 km. The route begins on the Taman Peninsula, passes along the existing five-kilometer dam and the island of Tuzla. Then it crosses the Kerch Strait, rounding Cape Ak-Burun from the north, and reaches the Crimean coast.
Earlier, Kyiv expressed that, according to the head of the Ministry of Infrastructure of Ukraine, Yuriy Lavrenyuk, this will lead to a reduction in the number of ship calls at the ports of Mariupol and Berdyansk. This circumstance, in turn, will lead to a decrease in the profits of trade operators and the administration of Ukrainian seaports.
SIMFEROPOL, August 29 – RIA Novosti, Maxim Groznov. The railway arch of the bridge under construction across the Kerch Strait weighing 6 thousand tons is fixed on fairway supports at an altitude of 35 meters above the water level, the Crimean Bridge information center reported.
The operation to install the railway arch span of the bridge across the Kerch Strait began on Sunday morning, and shipping traffic in the strait was suspended for 72 hours. The arched span, 227 meters long and 45 meters high, was transported using floaters to the fairway supports. Lifting of the arch using powerful jacks began late on Monday evening and was successfully completed on Tuesday morning.
“The railway arch of the Crimean Bridge has been lifted onto the fairway supports and securely fixed at the design height of 35 meters from the water. The ship and aeronautical alarm system is already operating on the structure. Final installation on the fairway supports will take another three weeks,” the message says.
“The production of the arch, its assembly on slipways over the course of a year, the manufacture of the floating systems on which it was loaded, the fastening of the arch on powerful fairway supports: all together - this is a unique operation. We gathered the best specialists who were able to do this, and we are very grateful to them for this,” the information center quotes the words of the Chairman of the Board of Directors of Stroygazmontazh LLC Arkady Rotenberg.
© Info center "Crimean Bridge"
© Info center "Crimean Bridge"
The floating supports, with the help of which the arch was towed, returned to the Kerch shore for inspection and re-equipment. After carrying out the necessary procedures, a road arch weighing 5 thousand tons will be transported and installed. As a result, two arched spans will rise above the fairway, under which ships will pass unhindered, the Crimean Bridge information center noted.
The bridge across the Kerch Strait, which will connect Crimea and the Krasnodar Territory, will be the longest in Russia - its length will be 19 kilometers. The start of vehicle traffic on the bridge is scheduled for December 2018.
