scholarly journals Structural-technological solutions for the construction of roads on permafrost soils

2018 ◽  
Vol 5 (4) ◽  
Author(s):  
Aleksei Makarov ◽  
Alexey Kraev ◽  
Zurab Shankhoev

In this article, the authors briefly reviewed the problem of building roads on permafrost soils, according to the first engineering principle. The probable causes, affecting the thermal regime of the frozen soil at the base of the road, are also considered. In order to stabilize the road structure on permafrost soils, the team of authors of this article proposed 3 structural-technological solutions for the construction of roads, depending on the moisture levels of the upper soil mass, calculated for geotechnical and temperature-humidity conditions typical for the Yamalo-Nenets Autonomous district. The scheme, description and assessment of the effectiveness of each proposed structural-technological solution is given. Efficiency of the assessment is based on a comparison of the numerical modeling results of the water-thermal mode of mound with the proposed structural-technological solutions and ground embankments of roads on permafrost. The results of the numerical modeling of road embankments on permafrost soils are presented. The main conclusions of the research are formulated.

2021 ◽  
Vol 906 (1) ◽  
pp. 012090
Author(s):  
Andrey Melnikov ◽  
Pavel Kuznetsov

Abstract Changes in the geocryological situation at the road base and in the adjacent territory should be predicted based on an analysis of regional features of the “climate – landscape – cryolithozone – construction” system. These relationships are manifested in various ways across various cryolithozone regions, with these differences being rather poorly understood. In this regard, in 2019, the Melnikov Permafrost Institute (Yakutsk, Russia) and the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences signed an agreement on joint research work in order to elucidate the evolution of frozen soils, as well as to justify the application of certain measures to stabilise the permafrost environment. These projects aim to study the cryolithozone response along the routes of projected high-speed highways and existing railway tracks. Since 2019, the Institutes’ representatives along with specialists from the Tynda permafrost station (the branch of Russian Railways), North-Eastern Federal University (Neryungri, Russia), Zabtransproekt (Chita, Russia) and the Institute of Natural Resources, Ecology and Cryology of the Siberian Branch of RAS (Chita, Russia) have been investigating individual sections of the Far Eastern and Trans-Baikal railways in Russia. Some areas here are characterised by the continuous distribution of permafrost soils, while others – by island permafrost distribution. These areas share such common features, as the significant lifetime of linear structures (lasting for several tens of years) and the presence of deformations of the railway track, which appeared in the first years after construction. Railway track sections installed in high-temperature frozen soils are of particular interest for monitoring. However, the construction deformations are not always caused by frozen soil degradation. This article presents the results of surveys at one of such objects – a section of the track confined to the Chernovskaya station of the Trans-Baikal railway.


2021 ◽  
pp. 77-89
Author(s):  
I. S. Sukhachev ◽  
P. V. Chepur ◽  
A. A. Tarasenko ◽  
A. A. Gruchenkova ◽  
Yuhai Guan

The article proposes the design, design scheme and model of a vertical ground electrode system with lobe lugs for permafrost soils. The model was implemented using the ANSYS software. In the design scheme, the soil — ground electrode system is taken into account, the elastic-plastic properties of the soil are taken into account by the Drucker — Prager model. When modeling the work of the foundation soils, the Mises strength condition was adopted, according to which the equivalent stress is calculated under the condition of the material hydrostatic compression. The following boundary conditions are accepted: a cylinder-shaped soil mass is rigidly fixed along the lower face and along the side surface of the cylinder. Calculations are made for 5 standard sizes of grounding conductors. Maps of the distribution of stresses in the metal structure of the ground electrode (the rod and petals-emphasis) are received, the movements of the ground electrode in the soil mass are determined. The dependences between the maximum equivalent stresses in the ground electrode lobes and the value of vertical displacement in the ground base are established, as well as the amount of movement of the earthing pad, at which the effective equivalent voltages reach critical values in the area where the paddles are adjacent to the rod.


2015 ◽  
pp. 99-104 ◽  
Author(s):  
N. L. Mamaeva ◽  
S. A. Petrov

A research and comparison of natural and damaged (due to the active development of oil and gas fields) permafrost soils in the Jamalo-Nenets Autonomous Okrug were carried out. The analysis was run of correlation between an average monthly temperature of air, an average monthly sum of precipitation, the weight humidity and the thickness of the seasonal thawed layer. The conclusions were drawn about a poor resistance of landscapes on the permafrost rocks to the anthropogenic interventions, which in its turn is accompanied by the cryogenic processes and unfavorable influences on the Extreme North biosphere.


2018 ◽  
Vol 251 ◽  
pp. 04062
Author(s):  
Natalia Kupchikova

The article deals with the problem of determining the stress state of a complex pile structure with end broadening in the form of a sphere in the soil mass in the analytical form by a discrete method. The calculation schemes for determining the stress tensor at the boundary of the pile of square and circular cross-section with expansions in the soil massif are shown. The elements of the polynomial are found by the discrete method in rectangular and spherical coordinates, which is a cumbersome complex mathematical apparatus for a modern design engineer. The stresses are determined. At present, as the analysis has shown, the solution of complex geotechnical problems of soil bases and foundations for different types of loads in numerical modeling is carried out using modern software. Numerical modeling and calculation with the help of specialized software systems allows to consider the system “building-foundation-ground foundation”, as dynamic, integrally developing. However, the interaction of the components of this system requires a theoretical justification of the resistance of foundations in the ground environment, especially in complex engineering-geological conditions.


2011 ◽  
Vol 48 (5) ◽  
pp. 720-740 ◽  
Author(s):  
Richard Fortier ◽  
Anne-Marie LeBlanc ◽  
Wenbing Yu

Differential subsidence of as much as 0.85 m is affecting the access road to Umiujaq Airport in Nunavik (Quebec), Canada, located in the discontinuous permafrost zone. A geotechnical and geophysical investigation including piezocone test, ground-penetrating radar profiling, electrical resistivity tomography, and numerical modeling of the thermal regime of the road embankment and subgrade is presented to characterize the ground stratigraphy and permafrost conditions and to assess the exact causes and effects of permafrost degradation on the road embankment. The subsidence is due to thaw consolidation taking place in a layer of ice-rich silt underneath a superficial sand layer. While the seasonal freeze–thaw cycles were initially restricted to the sand layer, the thawing front has now reached the thaw-unstable ice-rich silt layer. According to our numerical modeling, the increase in air temperature recently observed in Nunavik cannot be the sole cause of the observed subsidence affecting this engineering structure. The thick embankment also acts as a snow fence favoring the accumulation of snow on the embankment shoulders. The permafrost degradation is also due to the thermal insulation of the snow cover reducing heat loss in the embankment shoulders and toes.


2021 ◽  
Vol 1928 (1) ◽  
pp. 012047
Author(s):  
A M Burgonutdinov ◽  
V I Kleveko
Keyword(s):  

2017 ◽  
Vol 122 (1) ◽  
pp. 332-353 ◽  
Author(s):  
Yingfeng Ji ◽  
Shoichi Yoshioka ◽  
Vlad Constantin Manea ◽  
Marina Manea ◽  
Takumi Matsumoto

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