TATLIN PLAN Лахта центр

ТАТLIN PLAN LAKHTA CENTER MULTIFUNCTIONAL COMPLEX

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original technologies

sergey nikiforov Such an unparalleled architectural object obviously required customized solutions. The complex exterior, its size, the tower out- line and many other parameters called for the need to devise and apply original tech- nologies and methods unusual for the case. If we wanted to speak about main engineer- ing solutions that made such a large-scale project possible, one should start the list with the base. First of all, a box-shaped foun- dation is to be mentioned. This pentahedral “box” comprising three slabs and shearwalls is a thick load-bearing structure. The bot- tom of the box is a 3.6 m thick slab, which is followed by an intermediate layer. Another 2 m thick slab closes the box. As a result, the tower load is first perceived by the up- per slab and then transferred to the box-type foundation. Next crucial element is the tower circular re- inforced concrete core vising from the foun- dation to the top floors. The core ensures the stability of the building and houses all neces- sary vertical MEP systems. One more struc- tural element to be referred to is outriggers, special external supports regularly located on four double-height levels along the height of the entire building. The fifth single-floor outrigger is placed on the top floor. These structural solutions substantially accelerated the process of the tower construction. We managed to transmit the load to the core by means of rigid connections between the up-

per and lower outrigger chords, which im- proved the project safety and robustness as far as progressive collapse is concerned. It is also essential to point out an element that enabled us to fully implement the origi- nal architectural design. I mean long-span composite plates linking the external perim- eter columns to the inner core. One should understand that the tower vertical columns are not installed vertically; they are inclined and create its twisted form along with other elements. The column tilt generates addi- tional stress for structures. We used com- posite floor slabs, which consist of concrete slabs, steel built-up cross-sections bolted with studs and profiled metal sheets in order to partially compensate it. This technology allowing fast, reliable and effective erection of typical floors will without doubt be soon employed for high-rise construction in this country. The top element of the high-rise building forms a spire, which can be attributed to main features of the complex for many rea- sons. To begin with, it was initially intended to be the quintessence of the whole architec- tural concept. Due to its geometry the spire shapes the complete image and makes the building visually blend in the city outline, which is defined by autonomous spires in a horizontally oriented landscape. Besides, the spire is of interest construction-wise. It

is supported by multi-tiered columns. Their installation process at the 83rd level of the tower was extremely difficult. There is a an observation deck in this zone; no horizon- tal connections and slabs were provided for by the design. It was necessary to erect the columns that formed the spire not part by part, but as a single element in order to come through the multi-storied space. Panoramic elevators in transparent shafts connected to the central core by “telescopic” bridges are installed on levels 83 to 86. Further up, the spire is a metal structure created with no reinforced concrete. The frame is self-sus- tained enough to deice itself owing to prop- erties of the material used and the applied solutions. There is not only a weather station, but also a GNSS antenna, which via satellite deter- mines the coordinates of the top point of the building and helps the monitoring system to supervise the tower state, at the very top. The unified monitoring system is worth men- tioning as a separate point. It was devised to observe the complex both in the process of its construction and during building op- eration. The system instantly responds to the slightest deviations from the design pa- rameters and tells you what actions to take. It can be compared with a single organism that constantly monitors all its structural el- ements and conducts self-diagnostics. This allows the condition of the entire building to be controlled every second. I must say that monitoring systems are used all over the world, but the Lakhta Center system has been developed specifically for the complex with its technological complexity and archi- tecture specificities in mind. It is indisputable that the Lakhta Center is already on the list of one of a kind architec- tural objects of the world since it is the tall- est building in Europe. Many high-rise con- struction specialists scrutinize it and strive to use our experience. I ammore than confi- dent that the technologies developed during the project implementation will be regularly used in Russian practice in the future.