气候变化领域集成服务门户(CCPortal): Numerical analysis for cooling effect of open boundary ripped-rock embankment on Qinghai-Tibetan railway

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DOI	10.1007/s11430-006-0764-z
	Numerical analysis for cooling effect of open boundary ripped-rock embankment on Qinghai-Tibetan railway
	Lai Yuanming; Zhang Mingyi; Liu Zhiqiang; Yu Wenbing
发表日期	2006
ISSN	1006-9313
起始页码	764
结束页码	772
卷号	49 期号:7
英文摘要	The heat convection of fluid inside the ballast layer and ripped-rock layer, which are regarded as porous media in railway embankment, is a process of heat and mass transfer. At present, the ripped-rock embankment, as a new type of embankment structure, has widely been used in the construction of Qinghai-Tibetan railway. However, because its ripped-rock layer is almost open in two bilateral boundaries and closed at top and bottom, and air can flow into/out of the ballast layer and ripped-rock layer, the convection and transfer heat patterns are very complicated in the embankment. Therefore, based on the temperature and geology conditions of the Qinghai-Tibetan Plateau, a numerical approach of the unsteady two-dimensional continuity, momentum (non-Darcy flow) and energy equations of heat convection for incompressible fluid in porous media is provided to analyze the velocity and temperature characteristics of the ripped-rock embankment with different embankment heights under open boundary condition for the coming 50 years in this paper. The calculated results indicate that, due to the influence of the outside wind, the convective heat transfer mainly relies on the forced convection in the open ripped-rock embankment. Even if the air temperature will be warmed up by 2.6 degrees C in the coming 50 years, it still has a better cooling effect on the underlying soils and a low temperature frozen-soil core is formed in the permafrost below it if the embankment is constructed in the regions whose present mean annual air temperature is -4.0 degrees C. Furthermore, the cooling effect of high ripped-rock embankment is better than that of low embankment. This is because the wider bottom of high embankment has a more influence dimension on the underlying frozen soil. However, cardinal winds on the Qinghai-Tibetan Plateau disturb its convection pattern, so that an asymmetric temperature distribution occurs under high embankment and it is possible to induce a transverse uneven deformation of embankment, but no similar situation occurs under low embankment. This asymmetric temperature field problem should be considered when ripped-rock embankment is designed and constructed.
英文关键词	open boundary; ripped-rock embankment; cooling effect; Qinghai-Tibetan railway
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS关键词	COLD REGIONS
WOS记录号	WOS:000239944300010
来源期刊	SCIENCE IN CHINA SERIES D-EARTH SCIENCES
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/239550
作者单位	Chinese Acad Sci, State Key Lab Frozen Soil Engn, Cold & Arid Reg Environm & Engn Res Inst, Lanzhou 730000, Peoples R China
推荐引用方式 GB/T 7714	Lai Yuanming,Zhang Mingyi,Liu Zhiqiang,et al. Numerical analysis for cooling effect of open boundary ripped-rock embankment on Qinghai-Tibetan railway[J],2006,49(7).
APA	Lai Yuanming,Zhang Mingyi,Liu Zhiqiang,&Yu Wenbing.(2006).Numerical analysis for cooling effect of open boundary ripped-rock embankment on Qinghai-Tibetan railway.SCIENCE IN CHINA SERIES D-EARTH SCIENCES,49(7).
MLA	Lai Yuanming,et al."Numerical analysis for cooling effect of open boundary ripped-rock embankment on Qinghai-Tibetan railway".SCIENCE IN CHINA SERIES D-EARTH SCIENCES 49.7(2006).