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冰川冻土 ›› 2015, Vol. 37 ›› Issue (1): 147-155.doi: 10.7522/j.issn.1000-0240.2015.0016

• 寒区科学与技术 • 上一篇    下一篇

风积沙对青藏铁路块碎石路基降温效果的影响

陈琳1,2, 喻文兵1, 韩风雷1,2, 刘伟博1,2, 易鑫1,2   

  1. 1. 中国科学院 寒区旱区环境与工程研究所 冻土工程国家重点实验室, 甘肃 兰州 730000;
    2. 中国科学院大学, 北京 100049
  • 收稿日期:2014-08-10 修回日期:2014-12-06 出版日期:2015-02-25 发布日期:2015-03-23
  • 通讯作者: 喻文兵,E-mail:yuwb@lzb.ac.cn. E-mail:yuwb@lzb.ac.cn
  • 作者简介:陈琳(1989-),男,四川德昌人,2012年毕业于西北农林科技大学,现为中国科学院寒区旱区环境与工程研究所在读硕士研究生,主要从事冻土环境与工程类方面的研究.E-mail:chl_sc@163.com
  • 基金资助:

    国家重点基础研究发展计划(973计划)项目(2012CB026102); 国家自然科学基金创新研究群体项目(41121061); 中国科学院"百人计划" 项目(喻文兵)资助

Impacts of aeolian sand on cooling effect of crushed-rock embankment of Qinghai-Tibet Railway

CHEN Lin1,2, YU Wenbing1, HAN Fenglei1,2, LIU Weibo1,2, YI Xin1,2   

  1. 1. State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2014-08-10 Revised:2014-12-06 Online:2015-02-25 Published:2015-03-23

摘要:

风沙危害正在威胁着青藏铁路的安全营运. 通过数值方法研究了风积沙填堵和覆盖青藏铁路块碎石路基后, 块碎石层降温机理以及降温效果的变化特征. 结果表明:开放条件下块石路基具有较强的强迫对流效应; 风积沙填堵后, 块碎石层降温效果减弱. 封闭条件下, 冷季路基坡脚处自然对流较强, 冻土上限抬升; 路基内部自然对流较弱, 由于路基填土作用, 路基中心处冻土上限抬升较大, 但随时间增长而降低; 沙层覆盖后, 块碎石层降温效果减弱, 路基下部冻土上限下降. 在气候变暖背景条件下, 封闭块碎石层自然对流减弱, 冻土上限下降, 不利于冻土路基的热稳定. 因此, 建议对沙害路段的块碎石路基采取补强措施.

关键词: 青藏铁路, 块碎石路基, 风积沙, 降温效果

Abstract:

Aeolian sand has damaged the Qinghai-Tibet Railway. In this study, the impact of aeolian sand on cooling effect of crushed-rock embankment of Qinghai-Tibet Railway is investigated on the basis of a coupled mathematical model of convective heat transfer and heat conduction with phase change. In addition, climate warming is also considered. The results show that extensive convection can be produced in the layer of block-stone for open block-stone embankment. After the crushed-rock layer filled with aeolian sand, it is clear that the cooling effect of crushed-rock embankment will drop off, which can be seen by analyzing velocity variation in the rock layer, then permafrost table will rise gradually. The cooling mechanisms of the closed embankment significantly depend on natural convection. The artificial permafrost table beneath the center of embankment is higher than that of the adjacent regions due to the impact of filling soil. After the surface of closed rock layer buried by aeolian sand, natural convection intensity weakens gradually. In addition, the cooling effect of rock layer can counteract the negative effect of climate warming and can uplift the permafrost table. The results can provide a guide for the infrastructure design and reinforcing Qinghai-Tibet Railway in permafrost regions.

Key words: Qinghai-Tibet Railway, crushed-rock embankment, aeolian sand, cooling effect

中图分类号: 

  • P642.14