Bearing capacity of frozen soils for foundations of objects in the North of Western Siberia

2020 ◽  
Author(s):  
Fedor Iurov ◽  
Valery Grebenets
Keyword(s):  
Bearing Capacity ◽  
Active Layer ◽  
Western Siberia ◽  
Transport Infrastructure ◽  
Pile Foundations ◽  
The Arctic ◽  
Frozen Soils ◽  
The North ◽  
Geological Conditions ◽  
Cryogenic Processes

<p>Keywords: permafrost, forecast, bearing capacity, foundation</p><p>The North of Western Siberia is a very promising region for industrial development. It is rich in oil and gas deposits, large settlements are located here and there is an extensive system of transport infrastructure (gas and oil pipelines, roads and railways). The territory has very differentiated permafrost-geological conditions in various types of landscapes. The development of new production sites, the construction and operation of infrastructure objects often activates dangerous cryogenic processes.</p><p>Trends in increasing air temperatures result in increase in the active layer depth, which leads to the decrease in the freezing area of frozen foundations, as well as in increase of the soil temperature, which reduces the forces of freezing. The problem is enhanced by the anthropogenic impact, which intensifies the negative changes in permafrost.</p><p>Quantitative estimation of changes in the bearing capacity of frozen pile foundations in the North of Western Siberia was carried out up to 2050 for various types of soils (sand, clay soils, peat) with trends in increasing temperatures of frozen soils and trends in increasing thickness of the active layer taken into account. Detailed calculations were carried out for the route of the “Vankor-Purpe” oil pipeline.</p><p>The calculations showed that maintaining current rate of climate warming, by 2050, there will be significant deterioration of the engineering-geocryological situation. The largest negative changes will take place in the southern part of the permafrost zone of Western Siberia (in the Tazovsky, Novourengoysky and Nadymsky districts), where the decrease in bearing capacity will exceed 50%. In the more northern regions (on the territory of Yamal), the predicted changes in the bearing capacity of frozen pile foundations by 2050 will not be so critical (no more than 20%). However, an increase in the thickness of the active layer can cause activation of the thermokarst process due to closeness of the thick stratal ice to the surface, as well as other destructive cryogenic processes.</p><p>In the region of investigation, under the influence of rising soil temperatures and an increase in the depth of seasonal thawing, the most vulnerable to climatic changes are loamy soils, which, according to the calculations, are characterized by the maximum decrease in the bearing capacity of frozen piles (up to 10% over 10 years). Sandy soils are more stable, a decrease in bearing capacity occurs in such areas at a lower speed (up to 5–7% over 10 years). Areas with moss-peat layer at the surface are less susceptible to changes in bearing capacity, however, with industrial methods of foundation construction, the layer is destroyed in places where the piles are built.</p><p>This work was supported by the RFBR grant 18-05-60080 “Dangerous nival-glacial and cryogenic processes and their impact on infrastructure in the Arctic”.</p>

scholarly journals Water tracks in the lower Lena River basin

2020 ◽  
Vol 163 ◽  
pp. 04007
Author(s):  
Anna Tarbeeva ◽  
Lyudmila Lebedeva ◽  
Vladimir Efremov ◽  
Vladimir Shamov ◽  
Olga Makarieva
Keyword(s):  
Active Layer ◽  
Surface Flow ◽  
Water Levels ◽  
Storm Event ◽  
Lena River ◽  
The North ◽  
Geological Conditions ◽  
North Western ◽  
Cryogenic Processes ◽  
Permafrost Regions

In the permafrost regions, where water filtration zone is limited by the shallow active layer, the surface flow forms a network of hollows, called «water tracks», oriented along the slope gradient. Water tracks are clearly distinguished on satellite images, but poorly defined in the field. The pattern of the water tracks network depends on geomorphological position, permafrost and geological conditions and dominant cryogenic processes. Surface flow could occur in the water tracks during the snowmelt and heavy rains, when the soil is entirely frozen or fully saturated by water. In dry periods, the water tracks form retention zones due to low filtration rates and significant capacity of thawed soil beneath the troughs. Our study of water tracks in the north-western Yakutia showed the changes of their morphology from upstream towards downstream. The water levels in the water tracks have a pronounced diurnal course in reverse phase to the water temperature variation. They are related to diurnal ground thawing dynamics. Hydrology of water tracks depends on the peat thickness, active layer properties and lithology. Water tracks formed by rubble rocks respond to a storm event with rapidly increasing water level. The deeper thawing layer, the smoother water levels rise and decrease.

The vegetation of the class Scheuchzerio–Caricetea fuscae Tx. 1937 in the Yanganape mountain massif area (Eastern macroslope of the Polar Urals)

2021 ◽  
pp. 113-149
Author(s):  
E. D. Lapshina ◽  
I. V. Filippov ◽  
V. E. Fedosov ◽  
Yu. V. Skuchas ◽  
P. Lamkowski ◽  
...  
Keyword(s):  
Species Composition ◽  
Western Europe ◽  
Western Siberia ◽  
The Arctic ◽  
New Associations ◽  
Polar Urals ◽  
Mire Vegetation ◽  
The North ◽  
The Polar Urals

There are very few publications on the classification of mountain mire vegetation in Russia. Several associations in the Southern Siberia mountains (Lapshina, 1996; Lashchinsky, 2009) and the Khibiny Mountains (Koroleva, 2001) are described. Mire vegetation in the Southern Urals is relatively well studied and described in the traditions of the ecological-phytocenotic dominant classification (Ivchenko, 2013; Ivchenko, Znamenskiy, 2015) while the knowledge on that of the Northern and Sub-Polar Urals is extremely limited. There is no information about the mires in the Polar Urals. The paper presents the results of classification of the class Scheuchzerio–Caricetea fuscae of the Yanganape mountain massif (67.68°—67.75° N, 67.72°—68.00° E) and adjacent plains in the Eastern macroslope of the Polar Urals, within the southern tundra subzone. The study area is mountain massif of about 250 m a. s. l., composed of limestone outcrops, with a wavy flat (60–90 m a. s. l.) plain around (Fig. 1–2). The classification is based on 138 relevés made in July 27–August 8, 2017 (Fig. 3). Relevés of similar syntaxa, established in the north of the Western Europe and the East European tundras (Ruuhijärvi, 1960; Dierssen, 1982; Lavrinenko et al., 2016), were included in analysis. DCA and t-SNE (t-distributed stochastic neighbor embedding) methods were used for ordination of syntaxa in multidimensional space (Maaten, Hinton, 2008). The calculations were made using the machine learning package for Python-Scikit-learn. In total, 13 associations, 11 subassociations, 12 variants from 6 alliances and 3 orders of the class Scheuchzerio–Caricetea fuscae were identified on the relatively small (about 70 km2) area. Within the order Caricion davallianae, syntaxa of the alliance Caricion atrofuscae-saxatilis, comprising low sedge-hypnum communities on carbonate mineral and organomineral soils in the mountains of the Western Europe, were identified and described for the first time on the territory of Russia. Three new associations (Ditricho flexicauli—Caricetum redowskianae, Tomentypno nitentis–Equisetetum palustre, Tomentypno nitentis–Eriophoretum vaginati) were described on the the Yanganape mountain massif (Table 1), which significantly expands the area of the alliance to the East. Alliance’ communities have some similarities with syntaxa of zonal dwarf shrub-grass-moss tundra vegetation (Lavrinenko, Lavrinenko, 2018), but are generally well differed by the species composition and community structure (Table 5). The order Caricetalia fuscae in the Eastern macroslope of the Polar Urals is represented by 4 alliances. In addition to Drepanocladion exannulati and Sphagno-Caricion canescentis, listed in the “Classification of Vegetation of Europe” (Mucina et al., 2016), we include into order the alliance Caricion stantis — moderately rich sedge-moss fen vegetation of the Subarctic and tundra zones, and the alliance Stygio–Caricion limosae, containing extremely waterlogged meso-oligotrophic and slightly acidic to neutral low sedge fens. There are 4 associations within the alliance Caricion stantis, including new ass. Scorpidio cossonii–Caricetum rariflorae (Table 2). Taking into account statistically significant differences in the species composition of sedge-moss communities dominated by various moss species (Fig. 15, 5-6), ass. Scorpidio scorpioidis–Caricetum chordorrhizae was taken out from ass. Drepanoclado revolventis–Caricetum chordorrhizae Osvald 1925 ex Dierssen 1982 broadly understood in the Western Europe. Its nomenclature type is the only relevé of Carex chordorrhizae-Amblistegium scorpioides-Ass. (Osvald 1925: 37), which sufficient for the original diagnosis, because it contains list of species with abundance and both name-giving taxa (ICPN, 2b, 7). The communities of both associations were identified in the Eastern macroslope of the Polar Urals, where they are represented by new subassociations, which significantly expands the distribution area of these associations to the East. Recently validly described in the Eastern European tundras (Lavrinenko et al., 1916) ass. Scorpidio revolventis–Caricetum rariflorae is also known for the North of the Western Europe (Dierssen, 1982). Its difference from western syntaxa is the absence of many boreal species, which are not able to exist in the severe climate in the North of Western Siberia, as well as the great number of plant communities with the diagnostic species of the alliance Caricion atrofuscae-saxatilis due to rich mineral nutrition, associated with the carbonate soils and calcium-rich groundwaters in the study area. New associations are established in two allian­ces: Carici aquatilis–Warnstorfietum tundrae in Drepanocladion exannulati and Sphagno squarrosi–Caricetum chordorrhizae in Sphagno–Caricion canescentis (Table 3). The floristic features of the latter alliance, whose communities on the northern limit of their distribution have a certain similarity to the arctic sedge-moss mire vegetation of the alliance Caricion stantis, are discussed. Oligotrophic communities of the alliance Scheuch­zerion palustris, occuring in acidic habitats, are placed in the order Scheuchzerietalia palustris that is in agreement with new interpretation of this alliance in the paper by Mucina et al. (2016). Two associations (Carici rotundatae–Sphagnetum baltici, Sphagno compaci–Caricetum rotundatae) are assigned to this alliance. There are few relevés for both Scheuchzerion palustris and Stygio–Caricion limosae alliances in the study area that is why their classification is preliminary, and it will be considered in the near future for the whole North of the Western Siberia on a larger data set. The classification results are confirmed by DCA-ordination of selected syntaxa (Fig.15, Б). However, the differentiation of communities is more clearly demonstrated by the t-SNE method, which allows displaying multidimensional hyperspaces on the plane (Fig.15, А).

scholarly journals Scientific Research in the European Part of the Arctic Territories in the Second Half of the 19th – Early 20th Century as a Part of the North of European Russia Modernization Program

2020 ◽  
pp. 774-785
Author(s):  
Anna K. Gagieva ◽  
◽  
Nikolay N. Gagiev ◽  
Keyword(s):  
20Th Century ◽  
Scientific Research ◽  
European Part ◽  
European Russia ◽  
Transport Infrastructure ◽  
The Arctic ◽  
Early 20Th Century ◽  
Historical Sources ◽  
The North ◽  
Stage Of Development

The article discusses main stages of scientific research of the arctic territories of the European North in the second half of the 19th – early 20th century. Drawing on historical sources and published literature, it concludes that the nature of research changed due to requirements of the time. It is known that the second half of the 19th – early 20th century was a time when society faced the task of expanding its reproduction base, which stimulated development of new spaces, introduction of new means of transport, and active inclusion of population and regions in production relations. The speed and efficiency of the developing commercial interactions between the territories came to the fore. Overcoming institutional and technical backwardness of the country and its territories involved a consistent expansion of the “effective national territory” by means of market development, spatial mobility of the main factors of production, capital, labor, and transport infrastructure improvement. The spatial expansion played a special part. The arctic zone of the North of European Russia presented great opportunities due its unique natural resources, and also prospects of solving geopolitical problems. This should have contributed to a new qualitative growth of production and transition to a new stage of development. Scientific research of the European part of the arctic territories, which was carried out at the time, was a part of the program of modernization of the North of European Russia, which unfolded on the pan-European scale. It was supported by the reorganization of administrative-territorial structure based on traditional structures of grass-roots management and prompted growing interest in the periphery as a source of resources for the growing economy; scientific research of the arctic territories intensified, as it became practical. Thanks to scientific research, the development of the Arctic territories became dynamic, which speeded up the integration of the region (in our case, the Komi krai) into the national space.

scholarly journals Fire-induced changes in soil and vegetation in the forest-tundra of Western Siberia

2020 ◽  
Vol 223 ◽  
pp. 03001
Author(s):  
Oleg Sizov ◽  
Leya Brodt ◽  
Andrey Soromotin ◽  
Nikolay Prikhodko ◽  
Ramona Heim
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Western Siberia ◽  
The Arctic ◽  
Fire Scars ◽  
Forest Tundra ◽  
The North ◽  
Tundra Vegetation ◽  
Lichen Cover ◽  
The Face

Wildfires are one of the main factors for landscape change in tundra ecosystems. In the absence of external mechanical impacts, tundra plant communities are relatively stable, even in the face of climatic changes. In our study, lichen cover was degraded on burnt tundra sites, which increased the permafrost thaw depth from 100 to 190 cm. In old fire scars (burnt 1980 – 1990) of the forest-tundra, vegetation cover was dominated by trees and shrubs. The soil temperature on burnt forest-tundra sites was higher in comparison to conditions of the unburnt control sites and permafrost was was not found at a depth of 2-2,3m. Dynamics of the Normalized Difference Vegetation index (NDVI) from 1986-2020 reveal that immediately after fires, vegetation recovered and biomass increased due to the development of Betula nana shrubs. In old fire scars of the forest-tundra (burnt 1980-1990), a significant increase in NDVI values was evident, in contrast to the unburnt tundra vegetation where this trend was less pronounced. We conclude that "greening" in the north of Western Siberia may occur due to fire-induced transformation processes. The role of wildfires in the advance of the treeline to the north, driven by climate change and active economic development of the Arctic, will gradually increase in future.

scholarly journals Post-war Projects of Academician V. N. Obraztsov for Development of Transport in the European North of the USSR

2021 ◽  
Vol 19 (3) ◽  
pp. 124-132
Author(s):  
L. P. Roschevskaya ◽  
M. P. Roschevsky
Keyword(s):  
Large Scale ◽  
Transport Infrastructure ◽  
The Arctic ◽  
The North ◽  
European North ◽  
Post War ◽  
Scientific Value ◽  
Scale Design ◽  
Short Time ◽  
Academy Of Sciences

In 2024, the Russian Academy of Sciences will celebrate its three hundredth anniversary. In this regard, there is a relevant need to comprehend the contribution of Soviet scientists to reconstruction of the country’s economy after the Great Patriotic War. In 2021, Russian University of Transport where Academician V. N. Obraztsov once worked, celebrates the 125th anniversary. The scientific conceptualisation of the ways to develop the North of the country is of great importance for the development of the transport system of Russia. Hence, those factors determine the topicality of the objective of the article to study the projects for development of transport in the European North of the USSR put forward by Academician V. N. Obraztsov in the post-war period.To attain this objective, the system-structural and historicalcomparative methods were used. For the first time the activity of V. N. Obraztsov, as of an analyst and expert in the field of development of post-war railway transport, is analysed. It is concluded that having the talent of a major leader of transport projects, Obraztsov put forward research tasks adequate to the requirements of the time for reconstruction of the country’s economy after the war. Among these tasks, he considered modernisation and development of transport. In the projects of 1945, Obraztsov laid the foundations for long-term planning of railway, road, river, and air transport in the European North of the USSR for several decades ahead. The volume of the proposed construction was enormous. Even though the planned large-scale design of the transport infrastructure was not entirely feasible for implementation in a short time due to limited forces and resources of the country, it catches imagination with farreaching prospects for development of the European North and the Arctic. Academician Obraztsov’s programs for development of the north, being of great scientific value, are especially relevant in 21st century.

scholarly journals Some clear evidences of the intrasedimental origin of massive ice in northern Eurasia

2020 ◽  
pp. 23-34
Author(s):  
Yurij Kirillovich Vasil'chuk
Keyword(s):  
Isotopic Composition ◽  
Late Pleistocene ◽  
Western Siberia ◽  
Ice Sheets ◽  
The Arctic ◽  
Northern Eurasia ◽  
Glacial Ice ◽  
Mountainous Regions ◽  
The North ◽  
Holocene Sediments

Massive ice is widespread on the territory of modern of Eurasian permafrost area: in the north of Western Siberia, Taimyr, Chukotka, and Arctic islands. Their thickness reaches 45-50m. The origin of massive ice is difficult to define due to the equifinality of such two different processes as intrasedimental freezing and formation of glacial ice. In both cases, thick massive ice is formed in various ways, but with the same final appearance. Three important aspects that show the evidence of the intrasedimental origin of massive ice in the north of Eurasia are examined. At first glance, they are obvious, but still fell out of sight of paleogeocryologists. It is shown that: 1) Any currently existing Late Pleistocene glacier, or part of it located under Holocene ice, have not yet been found within the Eurasian Arctic or on the Arctic islands with ice sheets, nor in the mountainous regions. 2) The isotopic composition of the vast majority of massive ice found in northern Eurasia is quite "Holocene", whereas in the north of Canada and Alaska, ice with a very light isotopic composition can often be found. 3) It should be taken into account that massive ice is found in the Holocene sediments of Western Siberia and Chukotka, where there is no reason to assume the glaciers spread to the plains.

The results of the Nineteenth Session of the North Eurasian Climate Forum (NEACOF-19), November 17-18, 2020

2020 ◽  
pp. 139-144
Author(s):  
V.M. Khan ◽  
Keyword(s):  
Information System ◽  
Climate Model ◽  
Climate Prediction ◽  
Transport Infrastructure ◽  
The Arctic ◽  
Arctic Zone ◽  
Climate Services ◽  
The North ◽  
Climatic Hazards ◽  
International Experts

The main results of the 19th session of the North Eurasian Climate Forum (NEACOF- 19) held online at the Hydrometeorological Center of Russia (Moscow) in November 2020 are presented. A brief overview of presentations of the leading Russian and international experts on the implementation of the WMO Climate Services Information System, the development of methods and technologies for climate prediction, vulnerability of transport infrastructure in the Arctic zone exposed to climatic hazards is given. Keywords: North Eurasian Climate Forum, North Eurasian Climate Center, Climate Services Information System, climate prediction technologies, climate model, climate warming, atmospheric circulation, consensus forecast

scholarly journals Influence of soil liquefaction on the design bearing capacity of a single pile

Vestnik MGSU ◽  
2020 ◽  
pp. 655-664
Author(s):  
Armen Z. Ter-Martirosyan ◽  
Le Duc Anh ◽  
Artur V. Manukyan
Keyword(s):  
Bearing Capacity ◽  
Seismic Waves ◽  
Strength Properties ◽  
Soil Liquefaction ◽  
Pile Foundations ◽  
Ho Chi Minh City ◽  
Single Pile ◽  
Suggested Technique ◽  
Geological Conditions ◽  
Seismic Impacts

Introduction. Pile foundations are considered one of the most suitable foundation solutions for construction in seismic areas. However, during earthquakes, specific processes often occur that adversely affect the interaction of piles with the surrounding soil. Soil liquefaction is one of the most difficult problems in geotechnical engineering in seismic areas, in which the soil will lose its strength properties. Assessing the effect of soil liquefaction on the design bearing capacity of piles during seismic impacts is an aspect of the design of pile foundations. Materials and methods. Using the formulas in standards documents for determining the design bearing capacity of piles with the suggested new technique on the hypothesis that after the influence of seismic waves and liquefaction, the soil with self-compaction pulls the pile down due to skin friction, i.e. additional downward loads affect upon the piles. Results. Various design cases are considered, with and without taking into account the effect of soil liquefaction on the bearing capacity of piles, under engineering and geological conditions in Ho Chi Minh City, Vietnam. A comparison is presented between the results in the considering various cases. Conclusions. The suggested technique allows to evaluate the reduction in the bearing capacity of piles after soil liquefaction. Further researches on the effect of soil liquefaction on the bearing capacity of piles are one of the main tasks in the design of buildings and structures in seismic areas for reduction in the risk of the catastrophic destruction of the foundations and buildings during and after an earthquake.

scholarly journals Fundamental aspects of the catastrophic gas blowout genesis and the formation of giant craters in the Arctic

2021 ◽  
Vol 11 (1) ◽  
pp. 51-66
Author(s):  
V.I. Bogoyavlensky ◽  
Keyword(s):  
Heat Flow ◽  
Western Siberia ◽  
Field Studies ◽  
Comprehensive Analysis ◽  
The Arctic ◽  
Formation Model ◽  
The North ◽  
The Earth ◽  
Process Formation ◽  
Anomalous Heat

The article considers the fundamental aspects of powerful explosive degassing of the Earth in the north of Western Siberia (mainly Yamal). The author presents the results of a comprehensive analysis and compilation of a large volume of factual materials obtained during field studies of a number of catastrophic gas blowout objects in 2014—2020. The author outlines that most of the craters found in Yamal are confined to the zone of anomalous heat flow in the area of the Bovanenkovskoye field. The researcher substantiates the process formation model of gas-saturated cavities in the massifs of ground ice, heaving mounds, blowouts and self-ignition of gas with the formation of giant craters and formulates the main features of powerful explosive degassing in the Arctic.

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