Increasing the Thermal Stability of the Embankment in Permafrost Regions

2021 ◽  
pp. 26-31
Author(s):  
A.F. GALKIN ◽  
M.N. ZHELEZNYAK ◽  
A.F. ZHIRKOV
Keyword(s):  
Thermal Stability ◽  
Thermal Stability Of ◽  
Permafrost Regions

The thermal stability of roadbed in permafrost regions along Qinghai–Tibet Highway

2003 ◽  
Vol 37 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Shaoling Wang ◽  
Fujun Niu ◽  
Lin Zhao ◽  
Shuxun Li
Keyword(s):  
Thermal Stability ◽  
Thermal Stability Of ◽  
Permafrost Regions

Effects of Framed Embankment for High-Grade Expressway in Permafrost Regions

2014 ◽  
Vol 505-506 ◽  
pp. 139-148 ◽  
Author(s):  
Wan Sheng Pei ◽  
Yuan Ming Lai ◽  
Ming Yi Zhang ◽  
Wen Bing Yu ◽  
Shuang Yang Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Thermal Stability ◽  
Global Warming ◽  
Scale Effects ◽  
Simulation Method ◽  
High Grade ◽  
Permafrost Table ◽  
The Difference ◽  
Thermal Stability Of ◽  
Permafrost Regions

Construction of high-grade highways is an important action to meet the requirement of communication and transportation in permafrost regions. Frame embankment is proposed to reduce the scale effects caused by wide pavement. Numerical simulation method is employed to analyze the improvement of frame embankment for thermal stability of roadbed, with the consideration of global warming. Compared the response of permafrost at symmetric position of each embankment to construction, the consistency degree of response is taken as decision fundament. Two indexes are selected, that is, the difference of permafrost table between the embankment and that at natural side, and the change of mean annual geothermal under the embankment. Additionally, the convenient for construction and wind-blown sand hazard are considered to determine reasonable frame space. So, numerical simulation of flow field of wind around embankments is carried out. It is concluded that the minimum space between two embankment is 6 m. The aim of this study is to provide scientific guidelines on construction of major permafrost engineering in the future.

scholarly journals Temperature Field Distribution and Thermal Stability of Roadbed in Permafrost Regions

2021 ◽  
Vol 39 (1) ◽  
pp. 241-250
Author(s):  
Youkun Cheng ◽  
Zhenwu Shi ◽  
Fajin Zu
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Temperature Field ◽  
Frozen Soil ◽  
Western China ◽  
Insulation Material ◽  
Structural Factors ◽  
Term Operation ◽  
Thermal Stability Of ◽  
Permafrost Regions

Many highways and railways in western China are built on permafrost roadbed. Frost heave and thaw settlement might cause diseases to frozen soil roadbed, such as deformation and cracking. For long-term operation, frozen soil roadbed should be kept stable and durable. Therefore, this paper analyzes the distribution law of temperature field of roadbed in permafrost regions, under the effect of thermal stability. Based on the thermodynamic properties of permafrost, the authors analyzed the influence of engineering geological factors, roadbed structural factors, and natural environmental factors on the thermal stability of frozen soil roadbed. Next, the antifreeze mechanism of frozen soil roadbed was described, together with the calculation methods for the relevant parameters. Afterwards, the temperature field of the roadbed with low thermal conductivity insulation material was analyzed by two methods, namely, steady-state thermal analysis and transient thermal analysis, and the solving process of roadbed temperature field was explained in details. The proposed analysis method and solving algorithm were proved valid through experiments. The research results provide a reference for the reasonable design of frozen soil roadbed.

The Application of Crushed Rock Materials upon Railway Embankments in Permafrost Regions

2011 ◽  
Vol 255-260 ◽  
pp. 4027-4033 ◽  
Author(s):  
Yan Hu Mu ◽  
Wei Ma ◽  
Zhi Zhong Sun ◽  
Yong Zhi Liu
Keyword(s):  
Thermal Stability ◽  
Warming Trend ◽  
Ground Temperature ◽  
Crushed Rock ◽  
Rock Materials ◽  
Ground Temperatures ◽  
Permafrost Table ◽  
Thermal Stability Of ◽  
Permafrost Regions

Crushed rock materials had been utilized extensively upon embankments, termed as crushed rock embankment (CRE), along the Qinghai-Tibet Railway in permafrost regions. Based on a long-term monitoring system along the railway, thermal stability and deformation characteristics and mechanisms of CRE were analyzed by field monitoring datasets from 2005 to 2009. The thermal stability analyses indicated that permafrost tables beneath CRE all had upwards movements but to varying degrees. For U-shaped crushed rock embankment (UCRE), the thermal stability of underlying permafrost kept well; along with permafrost table moving upwards, the shallow ground temperatures beneath the embankment decreased obviously while deep ground temperatures kept almost constant. For crushed rock revetment embankment (CCRE), the cooling effect was effective in cold permafrost regions. But in warm permafrost regions, the shallow permafrost beneath the embankment had no obvious cooling trend while the deep permafrost had a slight warming trend. The deformation analyses indicated that CREs experienced frost heave in permafrost regions with mean annual ground temperature (MAGT) < -1.5 °C but settlement in permafrost regions with mean annual ground temperature > -1.5 °C. The magnitudes of both heave and settlement were not significant. Since the better thermal stability of underlying permafrost, it was inferred that the settlement of CRE mainly originated from compression of warm and ice-rich permafrost layer near permafrost table.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

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