Analysis of thermal regime of a deep mine airway in permafrost

2020 ◽  
pp. 107-117
Author(s):  
S. Bandopadhyay ◽  
H. Wu ◽  
M. G. Nelson ◽  
V. Izaxon
Keyword(s):  
Author(s):  
Nataliya Belova ◽  
Nataliya Belova ◽  
Alisa Baranskaya ◽  
Alisa Baranskaya ◽  
Osip Kokin ◽  
...  

The coasts of Baydaratskaya Bay are composed by loose frozen sediments. At Yamal Peninsula accumulative coasts are predominant at the site where pipeline crosses the coast, while thermoabrasional coast are prevail at the Ural coast crossing site. Coastal dynamics monitoring on both sites is conducted using field and remote methods starting from the end of 1980s. As a result of construction in the coastal zone the relief morphology was disturbed, both lithodynamics and thermal regime of the permafrost within the areas of several km around the sites where gas pipeline crosses coastline was changed. At Yamal coast massive removal of deposits from the beach and tideflat took place. The morphology of barrier beach, which previously was a natural wave energy dissipater, was disturbed. This promoted inland penetration of storm surges and permafrost degradation under the barrier beach. At Ural coast the topsoil was disrupted by construction trucks, which affected thermal regime of the upper part of permafrost and lead to active layer deepening. Thermoerosion and thermoabrasion processes have activated on coasts, especially at areas with icy sediments, ice wedges and massive ice beds. Construction of cofferdams resulted in overlapping of sediments transit on both coasts and caused sediment deficit on nearby nearshore zone areas. The result of technogenic disturbances was widespread coastal erosion activation, which catastrophic scale is facilitated by climate warming in the Arctic.


2018 ◽  
pp. 72-78
Author(s):  
A. V. Gorbunov ◽  
Yu. A. Zhukov ◽  
E. V. Korotkov ◽  
A. V. Lekanov ◽  
V. G. Porpylev ◽  
...  

The vast majority of electronic devices on-Board Russian spacecraft is placed on a temperature-controlled mounting surface is ON, however, in some tasks there is a necessity to place a separate electronic units out thermostated panels on remote spacecraft design. The article presents an autonomous system of providing thermal regime of electronic blocks of spacecraft and objects of space technology that require maintaining the operating temperature and are unable to be installed on the thermostatic landing surfaces of spacecraft. The proposed autonomous system of providing thermal regime can operate autonomously in the extended operating temperature range of the installation surface from -80 to +80 °C when the supply voltage changes in the range from 75 to 550% of the nominal value. The review of the existing solutions is presented, the substantiation of the proposed decision is given, the structural scheme of autonomous system of providing thermal regime is given and its description and an example of application is given.


Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 423
Author(s):  
Chunde Ma ◽  
Jiaqing Xu ◽  
Guanshuang Tan ◽  
Weibin Xie ◽  
Zhihai Lv

Red shale is widely distributed among the deep mine areas of Kaiyang Phosphate Mine, which is the biggest underground phosphate mine of China. Because of the effect of various factors, such as high stress, ground water and so on, trackless transport roadways in deep mine areas were difficult to effectively support for a long time by using traditional supporting design methods. To deal with this problem, some innovative works were carried out in this paper. First, mineral composition and microstructure, anisotropic, hydraulic mechanical properties and other mechanical parameters of red shale were tested in a laboratory to reveal its deformation and failure characteristics from the aspect of lithology. Then, some numerical simulation about the failure process of the roadways in layered red shale strata was implemented to investigate the change regulation of stress and strain in the surrounding rock, according to the real rock mechanical parameters and in-situ stress data. Therefore, based on the composite failure law and existing support problems of red shale roadways, some effective methods and techniques were adopted, especially a kind of new wave-type bolt that was used to relieve rock expansion and plastic energy to prevent concentration of stress and excess deformation. The field experiment shows the superiorities in new techniques have been verified and successfully applied to safeguard roadway stability.


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