| Numerical Analysis for Temperature Characteristics of Open Boundary Crushed-rock Embankment on Qinghai-Tibet Railway |
| |
| 作者姓名： | Lai Yuanming Zhang Mingyi Liu Zhiqing Yu Wenbing |
| |
| 作者单位： | State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000 |
| |
| 基金项目： | The National Natural Science Foundation of China （No. ： 60272048）, Natural Science Foundation of Jiangsu Education Departnlent（No. 04kjb510057） and China Scholarship Council. |
| |
| 摘 要： | At present, in order to protect the stability of permafrost beneath embankment, the crushed-rock embankment, as a new type of embankment structure, has widely been used in the construction of Qinghai- Tibet Railway. Its crushed-rock layer is almost open in tow bilateral boundaries and closed at top and bottom, and air can flow into/out of the ballast layer and crushed-rock layer. Therefore, the convection and transfer heat patterns are very complicated in the ballast layer and crushed-rock layer of the embankment, which are regarded as porous media. In this paper, based on the wind, temperature and geology conditions of Qinghai- Tibet 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 provide to analyse the velocity and temperature characteristics of the crushed-rock embankment with different embankment heights under open boundary condition for the coming 50 years. The calculated results indicate that, due to the influence of the external wind, the convective heat transfer mainly relies on the forced convection in the open crushed-rock emban kment. Even if the air temperature will be wanned up by 2.6℃ 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℃. Furthermore, the cooling effect of high crushed-rock embankment is better than that of low embankment. This results from the fact that the wider bottom of high emban kment has a more influence dimension on the underlying frozen soil. However, cardinal winds on Qinghai-Tibet 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 emban kment, but no similar situation occurs under low embankment. This asymmetric temperature field problem should be considered when crushed-rock emban kment is designed and constructed.
|
| 关 键 词： | 青藏铁路 开放边界碎石堤防 温度特性 数值分析 |
| 收稿时间： | 2006-04-03 |
Numerical Analysis for Temperature Characteristics of Open Boundary Crushed-rock Embankment on Qinghai-Tibet Railway |
| |
| Lai Yuanming,Zhang Mingyi,Liu Zhiqing,Yu Wenbing.Numerical Analysis for Temperature Characteristics of Open Boundary Crushed-rock Embankment on Qinghai-Tibet Railway[J].Engineering Sciences,2006,4(2):134-142. |
| |
| Authors: | Lai Yuanming Zhang Mingyi Liu Zhiqing and Yu Wenbing |
| |
| Institution: | (State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000);(State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730001);(State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730002);(State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730003) |
| |
| Abstract: | |
| |
| Keywords: | open boundary crushed-rock embankment temperature characteristic Qinghai-Tibet Railway |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《工程科学》浏览原始摘要信息 |
| 点击此处可从《工程科学》下载免费的PDF全文 |
|
