Russia's VIS Group completes installation of 2,200-tonne cofferdam for right tower of Lena River Bridge in August

en.Wedoany.com Reported - Russia's VIS Group has completed the installation of the cofferdam for the right tower of the Lena River Bridge at its designed position on the riverbed. The group simultaneously completed the installation of two cofferdams in the river this season, creating conditions for simultaneous pile foundation construction for both bridge towers. The right cofferdam has a total weight exceeding 2,200 tonnes and a height of 17.5 metres. It was towed 300 metres from the right bank to the design point and anchored starting at 14:00 on August 19, and was flooded and sunk to the riverbed as planned at 2:38 Yakutsk time on August 21.

The cofferdam installation was carried out in stages: it was first assembled on a dedicated slipway on the left bank, then launched into a flooding dock, and towed to the right bank on June 3. The federal budgetary institution "Lena Basin Administration" (FBU 'Lena Basin Administration') completed dredging works, removing a total of 138,000 cubic metres of sediment.

Sergey Yudin, General Director of VIS Group, stated that the original plan was to install only one cofferdam this season, but given the bridge construction schedule requirements and the climatic characteristics of the Yakutia region, it was decided to install two cofferdams in the river this summer to create pile foundation work fronts for both bridge towers simultaneously. Drilling operations are already underway inside the central tower cofferdam.

According to Anton Krupnov, Construction Director of VIS Stroy LLC, after the cofferdam installation, work can proceed in the formed dry area. Drilling equipment will be placed on an internal metal frame, and boreholes will be drilled into the riverbed through a system consisting of 102 guide pipes for the construction of cast-in-place bored piles.

Considering factors such as severe floods, dense ice runs, and the short construction season, the project selected floating cofferdam technology, which is a first in Russian bridge construction. Specialists from VIS Group and Morbaza have completed the installation of two cofferdams in the river. This summer's water operations were supported by the fleets of the Lena United River Shipping Company, Vitim-Les, the Yakutsk Shipping Company, as well as VIS Group's own floating equipment, with a total of 19 vessels of various classes deployed at the Lena River Bridge construction site.

The Lena River Bridge is a cable-stayed structure that will be installed on three bridge towers. The right and left towers are each 194.5 metres high, and the central tower is 284.5 metres high. The construction of such an engineering structure on permafrost in the Arctic region is a world first. VIS Group is responsible for the design, construction, non-budget financing, and operation of the bridge until 2048. The project is implemented under a concession agreement with the Government of Yakutia and is part of the national project "Infrastructure for Life," with non-budget investment accounting for over 47%. The compensation distribution to investors covers the entire validity period of the agreement with VIS Group.