The technology that helps build on permafrost

Permafrost covers 65% of Russia’s land area. These areas are rich in natural resources and have highly developed infrastructure. Discover the technologies used to build and maintain facilities in permafrost.

Special conditions: A city in permafrost

Permafrost cities require special conditions and many restrictions. Take the inhabitants of Longyearbyen, a small Norwegian village on Spitsbergen. They must be trained to shoot and use rifles in case they encounter a polar bear.

Traditional burials are also banned. The permafrost prevents bodies from decomposing, which attracts dangerous predators, so the dead are shipped to the mainland. It is also illegal to have cats so as not to disturb the bears.

Underground ice

Permafrost, or cryolithozone, is the upper part of the Earth’s crust that is below freezing. It usually contains ice, frozen water and various gases.

The average annual temperature in Longyearbyen is minus 7 degrees Celsius (20 degrees Fahrenheit), there is no medical infrastructure and life is a struggle with nature. The settlement grew up around the coal mines in the early 20th century, and today there are over 2,000 people living in Longyearbyen.

Typically, northern towns are quite small. In Russia, however, many populous cities are built in the permafrost zone. Murmansk, Yakutsk and Vorkuta, to name but a few. Their populations began to grow rapidly in the Soviet years, as new industrial areas were created and infrastructure was actively developed.

Among the large Russian permafrost cities, the most notable are Dudinka (20,000 people) and Norilsk (over 170,000). Dudinka is Russia’s northernmost international port, while Norilsk is a major centre for non-ferrous metallurgy. Moreover, Norilsk is one of the three most comfortable Russian cities in a severe climate.

Seasonal thaw and pilings: how to build in permafrost

Norilsk and the Taimyr Mountains, where Nornickel operates, are completely surrounded by permafrost. But the conditions are not uniform: the permafrost extends to depths of 500 metres, some areas are occupied by non-freezing rock (known as talik), and average annual ground temperatures range from -5 to +7 degrees Celsius (23-44 Fahrenheit). “All of this affects construction conditions,” says Giorgi Kunchulia, an expert at Nornickel’s Climate Change Research Adaptation Unit.

Building in a permafrost zone is one of the most difficult engineering challenges. It may look like the permafrost surface is stable and never changes, but it is actually very dynamic. A major challenge for project developers is global warming and climate change, which is causing permafrost to degrade and thaw. The Ministry of Natural Resources has reported that 40% of infrastructure in the permafrost zone of the Arctic is at risk of degradation. By 2050, damage from degradation could amount to 5 trillion roubles (over $60 billion).

The stability of a building built in permafrost depends on its foundation and the maintenance of a constant temperature range. Design errors or misuse can accelerate the thawing process, eventually causing the structure to deform or even collapse. For example, the first temporary buildings in Norilsk, a wooden electrolysis plant and residential barracks, quickly fell into disrepair and collapsed in 1936-1937, almost immediately after the city was founded.

In 1937, Norilskstroy specialists concluded that the most suitable solution for industrial and civil structures in permafrost conditions was to use a ventilated underground cavity structure, with the building supported either by reinforced concrete columns or wooden piles embedded in boreholes.

This technology was flawed: the ground was warmed up, it would thaw, a pile would then be placed in the borehole, and then there would be a long wait for the permafrost to refreeze. In 1959, Mikhail Kim, a hydraulic engineer, solved the problem. He proposed that houses in Norilsk be built on piles, with boreholes drilled through the permafrost. Without thawing, the foundations took a fraction of the time to prepare. The ground remained frozen, and there was no danger to houses built on piles if they were handled properly.

Almost all of Norilsk is built on the principle of preserving the frozen ground. “At the same time, there are many ways to build and insulate. For example, building on piles and with a ventilated underfloor cavity, erecting buildings and facilities on substructures with surface insulation, cold ground floors, and the use of seasonally active cooling units or temperature stabilisers. Most buildings in Norilsk are built on piles over ventilated basements,” says Kunchulia.

There are many approaches to building in the Russian north, and preserving the permafrost is not the only option. For example, engineers can take into account the possibility of thawing; it is also possible to build on rocky ground or even on melted ground, as in central Russia. It all depends on the environmental conditions of the area, which are thoroughly investigated before construction begins.

A whole series of engineering studies and designs are carried out in order to select the most appropriate construction principle. “Now, as part of the Norilsk renovation programme, design and survey work is underway, and several socially significant facilities are already under construction,” notes Kunchulia.

Roads, pipes and permafrost

Sergey Goshovets, deputy head of Rosavtodor’s scientific and technical research, information technology and economic support department, says that several roads in the permafrost zone — A-331 ‘Viluy’, R-504 ‘Kolyma’, A-360 ‘Lena’, R-297 ‘Amur’ — are experiencing accelerated deformation.

For example, 313 pavement defects were registered on R-297 “Amur” in 2012. Despite rapid efforts to eliminate these defects, the number of deformations increased to 504 by 2015.

“The variability of the cryolithozone is the most difficult problem for road builders,” emphasises Mikhail Zheleznyak, Director of the Melnikov Institute of Permafrost Science at the Siberian Branch of the Russian Academy of Sciences. According to him, to prevent the ground from deforming, road builders first try to isolate structures from water and heat: they lay heat-insulating foamlex on the subgrade, protect embankments from the sun and precipitation with cantilevered canopies, and install pipes that transfer natural atmospheric cold to the road base.

Russia’s unique Zapolyarye-Purpe-Samotlor oil pipeline was commissioned in 2017. Most of the Zapolyarye-Purpe section was laid above ground. To implement the project from scratch, special pile-based supports were developed: fixed, longitudinally sliding, and free-moving. The new technology allows the pipeline to move slightly without deforming. The supports are equipped with soil stabilisers that maintain the soil’s natural temperature. The Russian specialists’ invention is protected by several dozen international patents.
Sources: Rosavtodor, Neftegaz.ru magazine

The implementation of new construction technologies requires serious research. In 2023, Nornickel, together with the Fyodorovsky Research Centre for Construction and Monitoring of Buildings and Structures in the Arctic, plans to create two permafrost test sites.

One will be used to test construction technologies on permafrost soils and new types of foundations, as well as to verify geophysical methods; the data will be used to build predictive models, a company representative said.

“A worldwide network of geotechnical test sites with a wide range of geological soil conditions has been established to test and verify innovative construction methods. However, there are few such sites in the permafrost zone. Norilsk will be one of the first regions to have its own test site,” says Giorgi Kunchulia.

Wells and sensors: how to save buildings

Over the next three years, a comprehensive permafrost monitoring system will be launched in Russia. As early as 2023, 30 pilot monitoring stations will be set up in the Russian North. In total, the system will include 140 stations. It is necessary for the efficient implementation of strategic plans for the development of the Russian Arctic zone.

“The thawing of the permafrost can lead to significant adjustments in the activities of individual companies and even entire industries, creating risks for the integrity of infrastructure facilities, including oil wells, pipelines and others. The aim of the monitoring system is to quickly record and analyse ongoing changes and facilitate timely decision-making,” said Dmitry Kobylkin, head of the State Duma Committee on Ecology, Natural Resources and Environmental Protection.

A similar system was in place in the USSR, but it effectively ceased to exist in the 1990s. During the Soviet period, however, there were fewer monitoring stations than there are now, about 20. Researchers at the time were involved in various practical tasks. For example, Vladimir Yanovsky, Leonid Bratcev and Vladimir Kudryavtsev, renowned Soviet engineers and permafrost scientists who worked at the Vorkuta permafrost station, were responsible for studying the properties of permafrost soils for the construction of coal mines; they also developed techniques for constructing residential buildings (a method of erecting buildings on underlays and construction of buildings with a ventilated subfloor), conducted surveys for the construction of the Vorkuta-Kotlas railway, the first railway built on permafrost, and carried out experiments on farming in the polar region.

Thanks to the research carried out at the Vorkuta permafrost station, an important strategic industrial region and a large polar city were created. Today, Vorkuta is considered a shrinking city – its population has fallen from 116,000 to 54,000 over the past 30 years. No new buildings are currently being constructed in Vorkuta. Many residents are trying to sell their homes and move away, driving down prices. A two-bedroom apartment, for example, can be bought for 160,000 roubles (less than $3,000). But without new permafrost monitoring stations, the situation is unlikely to change: building new houses and social facilities requires a thorough study of the subsoil.

Permafrost monitoring also has a special place in Nornickel’s operations. The Polar Division’s Centre for Monitoring of Buildings and Structures constantly monitors the condition of the ground at the foundations of buildings and structures. This monitoring ensures the safe operation of Nornickel’s facilities and protects the environment.

According to Russian regulations, when using the technique of keeping the ground frozen, the temperature should be monitored monthly during the construction of the facility and no more than twice a year during its operation. But Nornickel decided this was not enough. So the company set up an automated monitoring programme.

Implementing the programme

First phase. Large-scale studies of soil composition and properties. Rebuilding the network of thermometric monitoring wells in the region.

Second phase. Comprehensive survey of foundations and buildings. Identification of defects and anomalies. Development of geotechnical monitoring programmes.

Third phase. Equipping the company’s facilities with various sensors and instruments, including thermometric scythes (to measure the temperature of the ground at the base of buildings), thermohygrometers (for real-time monitoring of temperature and humidity in the technical spaces underneath structures), inclinometers (to monitor the spatial deviation of structures).

Fourth phase. Implementation of a centralised data collection, transmission, storage, processing and analysis system.

Fifth phase. Testing of remote sensor technology for qualitative estimation of vertical displacement values. Changing approaches to design and construction: all new objects must be automated and integrated into the information and diagnostic system.

Results: “Nornickel has ensured end-to-end automated control of parameters related to the safety of buildings in the Arctic zone, introduced digital technologies into the management and mitigation of risks related to the operation of the facilities, switched to digital document flow for geotechnical monitoring, changed the life cycle management model of the facilities, and increased the speed of informed management decision-making.

In addition to solving production problems, Nornickel is also involved in scientific projects. For example, the second joint polygon of the company and Fyodorovsky Zapolyarny State University will be located in an undisturbed (natural) area to test methods of background monitoring.

In 2022, the company’s Polar Division will also begin drilling 200 metre deep boreholes as part of a state programme for background monitoring of permafrost. A borehole in the centre of Norilsk dating back to the 1960s was restored, and four other boreholes were drilled in the settlements of Talnakh, Kaierkan, Oganer and Dudinka.

“Our actions will make it possible to assess the impact of technogenic and climatic factors on the permafrost over the past 60 years and to develop cost-effective adaptation measures,” concludes Giorgi Kunchulia.