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Triumph and weekdays. How to install the spire on the skyscraper Lakhta Center. Part 2

The installation of the constructive completion of the spire of the Lakhta Center tower resembles a military operation: preparation - waiting - signal - blitzkrieg: lightning-fast conquest by a man of Europe's highest celestial mark.

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Installation of the final part of the spire took less than a day. Waiting was delayed for two days. But the preparation ... It began at the dawn of floor-by-floor construction, even before the appearance of giant tower cranes on the shores of the Gulf of Finland.

Crane training


It was not for nothing that powerful lifting machines of the Lakhta construction site were recalled. In this painted as on the notes of the building party they played one of the main roles.

By October 2017 around the skyscraper - a trio of "libherry." Crane "K-4", which worked in the center of the core, has already been disassembled: the core ended at level 88.

Lifting trinity - machines based on the model Liebherr 710HC-L 32/64 - the largest crane with a swing arm, manufactured by a global manufacturer. But these cranes are not from the mass conveyor. They were created specifically for the construction of Lakhta Center. Crane "K-3" - to install the final part of the spire constructive.

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“... Liebherr manufactured cranes for a skyscraper on a special project, there were separate calculations, a separate project for these machines, the working conditions of cranes at peak heights, wind were separately calculated,” says Liebherr service engineer Sergey Prochukhan.

There are two reasons for this: architectural features and microclimatic conditions for the construction of the Lakhta Center tower.
““ The solid monolithic core of the Lakhta Center tower goes up to level 88, above — even more than 100 meters of metal structures. The metal structures of the spire, of course, do not withstand the load from the fixings of cranes, therefore the cranes are fixed at the highest possible height - 355 meters, ”says Renaissance Construction engineer Rustam Doschanov.

The spire of the tower is a steel half-timbered in a metallized shell. Bearing meter pipe-rack and weight of 2000 tons - inspire, but only so far you can not compare the scale of the rest of the Supertoll. Each crane attached to the supermassive core of the tower gives a load of 240 tons to the structure! Elastic and light structure of the spire can not cope with this.

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The second important point is the wind. The standard limit for crane operation is 15 m / s. For heights of mass construction, such gusts of wind are not a frequent occurrence, it is possible to build. On the skyscrapers marks - and the wind to match ...
“At altitudes of 300–400 meters, the wind speed was often 120 km / h, the wind record was 141 km / h!” Says Rustam Doschanov.

It is not surprising that the construction in Lakhta has become a real challenge for the manufacturer of lifting equipment. The cranes were designed special - such that they would safely stand even with very strong wind and reach the spire mark.

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The last crane attachment to the center of Lakhta Center is at 355 meters.

After this pristezhka at cranes begins free-standing part of the tower, composed of reinforced sections. Due to technical solutions, it was possible to resolve the issue with the winds. Estimated wind speed for giant Lakhta cranes - 164 km / h! The highest level of assessment of wind speed on the Beaufort scale! Of course, it is impossible to work with such a hurricane - but the towers will safely stand under the blow of a similar element.

About helicopters


Why did the installation of the top-end construction not be carried out with the help of helicopter technology, for example, as when installing a new antenna on a Petersburg TV tower?

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Installation of the antenna on the St. Petersburg TV tower, 2011. Installation is carried out with the help of a Mi-8 helicopter with a high-class crew. Photo source

Rustam Doschanov, engineer at Renaissance Construction: “This option was also considered as an alternative. The mass of the top of the spire is 8 and 13 tons. The most optimal weight of the structure for mounting by helicopter is 5 tons: a helicopter with a carrying capacity of 5 tons is most stable in the air. We considered the proposal of the helicopter company, which has a helicopter with a carrying capacity of 20 tons. It is difficult to mount such a large helicopter - it is not stable in the air, it is difficult for installers to fix structures. And our cranes have a frequency converter that allows you to smoothly raise and lower structures to the nearest millimeter. ”

Sergey Prochukhan, Liebherr service engineer: “Compared with the helicopter, the crane provides very accurate positioning of the load. In a helicopter installation case, the determining, critical factor is the skill of the pilot and installer. At installation by the crane influence of a human factor is much less. The crane provides an opportunity to file very carefully and safely for installers. ”

By the end of January, the position of the “senior” libkher, the K-3 lifting machine, approached 450 meters in jib. Ahead is the main challenge, the one for which K-3 was designed even before the start of floor-by-floor construction.
But back to the spire.

Lahta Center Peak


The builders assembled most of the tower's spire on the object from steel pipes and connecting beams. The story of the final design is different: she arrived in Lakhta from the factory almost ready-made.

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The top design of the spire - tower peak - is a cone of three horizontally separated elements. On the bottom later install the SOF and facade. The tops are already delivered fully assembled: a frame in a stainless steel shell, with straight edges on the outside corners. To the peak of a cone, the faces that run from the bottom of a skyscraper and continue in the architecture of its spire converge at one point. The Lakhta Center Tower twists from the base to the top 90 degrees and opens up at this end.

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Training


From the message of the manufacturer, the company Gartner:
"(The spike tip cone is approx.) ... was made from stainless steel sheets up to 8 cm thick in Gundelfingen with the assistance of mechanics specializing in stainless steel products from Goppingen. to create complex designs. "

Production of construction at the factory in December 2017-January 2018:

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Welding stainless steel. Upper part of the frame structure


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Structural frame

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Preparing the base frame design

Ten holes - for future connection with a supporting ring beam mounted on the central pillar in the tower at 449 meters.

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Peak base - attachment points for upper and lower parts of the structure

The finished structure is sent to Petersburg, to the construction site of Lakhta Center ^

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Meanwhile, in Lakhta Center ... January 2018

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The site of the future installation of tower peak is the central column in the spire of the Lakhta Center tower, elevation 449 meters

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The builder applies fire retardant and paintwork on the supporting annular beam, which subsequently connects the central column in the spire and its peak. Ground operation



The final design of the spire arrives at the construction site

Everything is ready for the final. But until the triumphant moment will pass two more days.

Expectation


“The most difficult thing at this stage is to wait for the weather. Now everything is ready - you have to wait for the window. When the wind will be steadily low so that the cranes and people can work, ”says Igor Romanenko, construction control engineer at Lakhta Center, on the eve of the installation of top construction.

Builders really need a couple of nice days to bring the crane to the mark, and people - to the peak of the spire. And now - a good forecast: January 28 and 29 - time for high achievements.

Installation


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Preparation of the crane "K3"

By the end of January 2018, the giant Libcher has already left behind all European supercranes. The bravest London crane operator, who mounted the peak on the Shard skyscraper, and the brave guys who managed to lift the final designs of the towers of Moscow City - were not at such elevations.
But ahead - the main step up. Right before the installation of the final design, the K-3 crane is additionally increased: plus three sections of 5.8 m each and one of 2.85 m stand at the base of its metal tower. The height of the goose-467.3 m! This super step is possible only for a short time - stability with a wind below 100 km / h and work with a wind of no more than 50 km / h.

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Supersteg crane "K3"

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The lower part - the base of the cone spire - in readiness

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At the start

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First go! Lifting to the installation level at the level of 449-450 meters

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Ring beam, which will fix the base of the final design

After installation, the lower part constructs will be circumvented by the SOF and with a facade and will be complemented with lighting. In the meantime, the task of installers is to quickly install and prepare to receive the peak of the spire.

Early morning January 29, 2018

On the ground

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Last design check before sending to the assembly level and installation of fixing cables for lifting with a crane

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Even on the ground at the top of the spire there are lights of light-marking, architectural lighting and anti-icing system (heated). Check all systems

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Sling cargo on a crane hook

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The rise has gone! Separation - to the applause of the builders

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Climb

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One second before escaping sight of the earth

Docking process:

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Notice how gently and precisely the crane lowers the load to the mark. This is extremely important for the safety of climbers - in the case of a helicopter, the buildup of a load and a strong outflow to the installers from under the blades of the aircraft would be inevitable.

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The length of the crane cable is almost half a kilometer!

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Docked! Here, applause would have been even more appropriate, but only those who are at a high point can see this picture.

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There is a mounting peak. The second group of climbers works at over 460 meters on the outer wall of the structure!

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The work is completed. At the peak of the tower lights came on - light markings for aircraft. Now this signal from the ground will always be on.

After installing the peak of the spire, the K-3 crane is immediately lowered to its original position. The super step for which it was designed is made.

Rustam Doschanov, engineer at Renaissance Construction: “The installation is completed - this is a confirmation that we did everything correctly. Everything is calculated, checked and rechecked. But some risks still always exist. Only when the case is finished, we can definitely sum up: we did everything right. ”

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THE BEAUTY OF THE HIGH WONDER


The construction of the spire is a unique construction operation. But every big deal consists of everyday life. For four months, each builder engaged in the construction of the spire, performed his daily task. Let's look at the construction days of this period.

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To work - the rise!


Everyone who is busy at the installation of the Lakhta Center spire understands this phrase literally: they really have to get up to work. This road - with transfers. Up to 52 floors - on the elevator. Office "shindler" - fast, quiet and smooth - have already begun their labor mileage. Their mission is honorable - they carry those who build a tower, giving the most valuable things a person has - their work, time, and of course, love for their creation.

Elevator cabins are still covered with protective screens - from accidental damage during construction.

From the 52nd floor, you need to go for a transfer - up to the 81st floor there is a construction elevator, a reliable slug.

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The next leg of the journey is the slowest: on a monolithic staircase, and from the 89 level of the tower - on a lightweight metal staircase in the spire.

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If the construction debt calls even higher, then you are:

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Staircase in the central column of the spire

The main difficulty of this segment of the path and this area of ​​work is not even height, but space constraint.

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But above - absolute and dangerous space.

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The final section of the spire - tower peak - in the factory environment

These nine steps along the outer part of the facade of the 13-meter structural completion of the spire, lead up to the mark of 462 meters. This section of the climb - only outside and only for industrial climbers.

The entire walk-lift route can take up to 40 minutes. In the near future, visitors to Lakhta Center will reach the 87th floor in 45 seconds.

In Petersburg - the wind


At the construction site Lakhta Center everything is provided. The wind is not at the mercy of the people.
“To work on the steeple, the wind must be lower than 15 m / s in order for the cranes to be able to work ... People in open structures of the spire are also not allowed in bad weather conditions - there is an inspector on the 88th floor who controls coming to higher levels: tolerance, availability of PPE and weather conditions, ”says Igor Romanenko, construction engineer of Lakhta Center.

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Strong wind expected? All - on the way out. No level above 88

Construction is on a tight schedule, but there is a strengthening of the wind - and you just have to wait, and then - catch up. In total for 2017 there were more than 100 warnings from the Ministry of Emergency Situations about the unfavorable strengthening of the wind in St. Petersburg. This is almost a third of the year. The four-month operation to install the tower spire had 18 days with a strong wind.

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Windsock on the tower spire. December 2017

Wind is the most changeable component of the high-altitude microclimate. The temperature at the top and bottom may vary not so much. But the wind - quite often. In 2017, builders recorded gusts of a force of 141 km / h!

Snow and frost


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Insulated clothing is required when going upstairs. “Upstairs it is even cold in summer ,” says AECOM’s construction control engineer Alexander Pimakin. In winter equipment includes jackets, pants, balaclava, gloves - all the most insulated, waterproof and windproof. Shoes - on non-slip soles with a metal insole - from accidental damage.

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In such equipment it is difficult to distinguish who is who, but only to the uninitiated person. Just as in the army, the branches of the troops differ in color and shape of the uniform, so on the construction site - they can be distinguished from the team of which contractor and which specialty is the builder. Command personnel, engineers - in poisonous-green signal vests and white helmets. In gold - surveyors, in green - labor protection and quality control engineers, in blue - mechanics, gray - foremen, in orange - concrete workers and steel fixers.

Climbing equipment is a sure sign of a high-altitude builder. For anyone who goes to the open structure - in particular, on the spire, a five-point tether and continuous insurance in two places are obligatory.

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But the crane operators, when working in the crane cabin, can be dressed quite easily, despite the awesome snow-white exterior of the cranes.

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Inside the tower cabin - the stove, the windshield will be cleaned by the “wipers” - everything is just like in a regular car.

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But to get up without working clothes is not enough: the last bridge is at 355 meters, then another 90 meters up the metal stairs in the crane tower.

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Transition bridges

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Inside the boom crane

The assembly of metal structures at sub-zero temperatures is the subject of close monitoring. Before lifting to the assembly level, all parts are thoroughly cleaned of snow, ice or dirt.

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Installation of scaffolding. January 2018

When assembling monitor the temperature. If the thermometer is below minus five - for some operations, correction factors are introduced or heat levels are set.

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On the steeple of Lakhta Center. Air temperature is minus 9 ° С. January 2018

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Spike space in hoarfrost. After mounting the structure is frosted over

In the dark night


Winter north day is short. December twilight covers the city already in four days, light day - a little less than six hours. Construction goes around the clock. The area of ​​the spire is no exception, despite its elevation and construction operations in the dark season.
Many people are accustomed to building lighting the tower. The electricians of Lakhta Center are in the forefront - temporary power supply lines are quickly pulled to rapidly increasing sections of new levels. Thanks to their work, installers are always with light, the dark season is not a hindrance.

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Work on the steeple at dusk. December, 2017

Unforgettable


Most memorable? The entire amount of metal structures that I assembled during all the previous time of my work - and this is 20 years - including during the construction of offshore platforms - drilling, shipment - is only half of what is here, in Lakhta Center ... And more- once , while climbing up, was in two levels of clouds. On the 30th floor - the first cloud, then - around the 70th floor - the second cloudiness level, and around the 80th - turned out to be above the clouds, like on an airplane when you fly out of the clouds - and there is the sun , ”says Igor Romanenko.

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" The construction of Lakhta Center itself - I did not see such complexities and delight in technical performance. The architecture is very complicated, and everything is embodied. Everything is from the metal to concrete works, the facades are top-notch ," says the service engineer Liebherr Sergey Prochukhan, - "And yet - sunsets."

“Unique super massive tower constructions. Wonderful sunrises and sunsets, and the city under the clouds " , - share unforgettable Alexander Pimakov from AECOM.

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Sunrises and sunsets over the tower of Lakhta Center. Summer 2017- January 2018

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The first part of the material here .

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SHORT DOCUMENTARY VIDEO ABOUT STUD TOWER LAKHTA CENTER



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Thank you for your help in preparing the material for the construction control engineer of the IFC customer service Lakhta Center Igor Romanenko, AECOM construction control engineer Alexander Pimakin, Renaissance Construction engineer Rustam Doschanov, Liebherr service engineer Sergey Prochuhan.

Photos of Vyacheslav Korolev (operation on installation of the spire, inside the spire), Nikita Grigoriev (photo from cranes), Ruslan Genk (photo from cranes), Nikolai Gontarya (summer), Ivan Smelov (summer), Igor Romanenko (clouds), Rustam Doshanov ( cranes, a spit mounting operation), Alexander Pimakin (clouds over the city, sunset), Viktor Sukhorukov (final photo).

Source: https://habr.com/ru/post/409811/