Bridge crossing over the Lena River near Yakutsk | JSC "Giprostroymost Institute — Saint Petersburg"

The Lena Bridge is unique because it is being built in the extreme conditions of the Far North, including severe frosts, heavy ice, severe floods and complex logistics of material delivery. Taking into account the Lena riverbed and climatic features, the possibility of flooding, the option of building a cable-stayed bridge was chosen. It is approved by the Scientific and Technical Council of Rosavtodor. Calculations for a cable-stayed bridge are made taking into account temperatures up to -65 degrees with a dynamic load.

Cable-stayed bridges are being built specifically to facilitate the passage of icebreakers on rivers. In this case, the bridge supports can be installed far from each other. In the Lena Bridge project, the span between the pillars will be 840 m.

To implement the project at the initial design stage, a full range of scientific research was carried out with the participation of leading Russian institutes. Mathematical and physical modeling of hydrodynamic, riverbed and ice processes, the study of the aerodynamic stability of superstructures, and an experimental study of the interaction of ice with bridge supports in an ice experimental basin were performed.

The cable-stayed structure of the bridge is technically complex and unique for the harsh climatic conditions of Yakutia. There are no similar examples in terms of the construction of cable-stayed bridges in the Far North in world practice.

Key elements of the Lena River Bridge

The symmetrical three-part composition of the pyramidal pylons, forming a rhythmic series, has a unique architecture, and the pure expressive constructive forms fit succinctly into the natural landscape. The central pylon is diamond-shaped, four-post (pyramidal), with a height of 284.5 m.

It is the dominant feature of the Lena Bridge. The architectural feature is the top of the pylon, inspired by the Yakut musical instrument, the harp. The side pylons are diamond-shaped double-post with a height of 194.5 m.

Railings are an integral part of bridge structures. Performing their main functions, the structural elements of the railing form the letter L, which symbolizes the name of the Lena River, and the minimalistic coloristic solution supports the conciseness of the form. Another value of the element is Urasa. A type of ancient Yakut summer dwelling, a cone-shaped tent made of poles, covered with birch bark. It is believed that Urasa is the most ancient form of Yakut dwellings.

Socio-economic effects

• Reducing the cost of the "northern delivery". Annual budget savings of at least ~ 4.7 billion rubles (2028)
• The growth of year-round transport accessibility of the Republic's territory from 20.9% to 87%
• The annual growth of the Republic's GRP will amount to 2.5-3% (~ 100 billion rubles over the Project period)
• The possibility of developing a deposit in the gravity zone of the bridge
• The volume of mineral extraction tax to the federal budget for the period of field development is 4.2 trillion rubles (200+ billion rubles per year in the first few years after the Lena Bridge was commissioned)

The additional effect of the creation of the Northern Latitudinal Belt (NSR)

The construction of the Lena Bridge will create a significant part of the UWB and form a year-round highway connecting Eastern Siberia through the territory of Yakutia with the Magadan region. The implementation of the project will contribute to the development of deposits and increase socio-economic effects.

Summing up, it is important to note that the implementation of this project in conjunction with the overall development of the transport infrastructure of the Sakha Republic will open up prospects for the economic development of both the entire region and the city of Yakutsk. The holistic, concise image of the object will smoothly fit into the landscape, decorate the environment, and allow it to become the hallmark of the republic.

Technical description of the bridge structure across the Lena River in the Yakutsk region

The body of the central pylon (pillar No. 9) in the variable water level is designed to be prefabricated and monolithic in the form of a decagon circumscribed around a circle with a diameter of 26 m, filled with concrete. The massive part of the support above the estimated 1% retaining level of the high ice passage is made of a similar shape in a monolithic design with additional cantilever overhangs supporting the upper part of the pylon. Above the stiffening beam, the pylon consists of four struts united by a diaphragm at 265.5 m.

The cross section of the pillars is designed as a pentagon inscribed in a circle with a diameter of 7 m, with a wall thickness of 1.2 m. Above the level of the union of reinforced concrete pillars, the body of the pylon is designed in steel with additional thrust beams and diaphragms that transfer forces from the anchors of the cables to the body of the pylon. The execution of the metal structures of the pylon is northern B, steel 10XSND-3.

The mounting joints of the blocks are frictional on high—strength M22 bolts designed for bridge construction, climatic design of CL. Inside the pylon, above the stiffening beam, observation ladders are arranged to the full height, and a cargo and passenger lift is also provided. From the top of the grillage, the height of the central pylon is 279 m.

The lateral pylons (supports No. 8 and 10) in the variable water level are designed as prefabricated monolithic decagonal sections with elongated side faces. The filling concrete is B35 F1300 W8. Above the estimated 1% retaining level of the high ice flow, the body of the pylons is designed in an inverted Y-shape made of monolithic reinforced concrete B45 F1500 W12.

The cross section of the pylon pillars is a rectangle with truncated outer edges. The width of the pylon posts along the facade is 6 m.

At the shroud mounting level, the pylon has a steel-reinforced concrete section with additional steel thrust beams and diaphragms that transfer forces from the shroud anchors to the pylon body. Inside the pylon, observation ladders are arranged at full height. The height of the side pylons is 182.52 m from the top of the grillage.

The intermediate supports of the riverbed part of the bridge structure and the approach overpasses are made in the form of a single prefabricated monolithic strut with a diameter of 4 m. A monolithic reinforced concrete crossbar made of concrete B35 F2300 W8 is arranged on top of the rack.

The foundations of the supports are designed from bored piles with a diameter of 1.5 m. Concrete grillings — B45.