青藏铁路多年冻土区普通路基热状况监测分析

doi:10.7522/j.issn.1000-0240.2014.0115

摘要/Abstract

摘要： 基于现场地温监测数据，选取年平均地温不同的监测断面对青藏铁路普通路基的热状况进行分析，包括多年冻土上限变化及其地温变化、下伏多年冻土温度变化、原天然地表附近热收支等方面. 结果表明：在低温多年冻土区，路基下部多年冻土上限均有所提升，且新近形成的人为上限较为稳定，冷季时负温积累显著；路基下伏多年冻土总体热稳定性较好. 而在高温多年冻土区，左（阳坡）路肩下部多年冻土上限多表现为下降，右（阴坡）路肩下部多年冻土上限有升有降，但是新近形成的上限均温度较高且有进一步升温的趋势；与天然场地地温相比，路基下部多年冻土均出现一定的升温. 尤其在高温极不稳定多年冻土区，天然场地多年冻土自身处于吸热升温状态；路基修筑后，下部多年冻土已经出现了融化夹层及双向退化的情况，路基热稳定性较差. 对于普通路基来说，由于青藏高原强烈的太阳辐射及青藏铁路总体走向原因，普通阴阳坡效应显著，左、右路肩下部多年冻土热稳定性差异较大.

关键词: 普通路基, 多年冻土, 热稳定性, 热收支, 青藏铁路

Abstract: Based on in-situ observed ground temperature data, some typical monitoring sites with different mean annual ground temperatures (MAGT) are selected to analyze the thermal performance of traditional earthen embankment along the Qinghai-Tibet Railway. The analyses include the variations of permafrost table, temperature conditions of underlying permafrost and heat budget of shallow soils immediately beneath the original ground surface. The results indicate that in regions with MAGT lower than -1℃, the permafrost tables under the embankment have been uplifted obviously and these newly formed permafrost tables have sufficient accumulation of cold-energy during cold season. Thus the thermal performances of these embankments are satisfactory. While, in regions with MAGT higer than -1℃, the permafrost tables under shady shoulders of the embankments all move upwards, while those under sunny shoulders move either downwards or upwards. Meanwhile, these newly formed permafrost tables beneath the embankments have slightly warming trends. Permafrost beneath the embankment is all warming slowly but progressively. In some more warmer sites, permafrost in the natural ground is in heat-absorbing stage. After the embankment construction, permafrost beneath the embankment experiences both downward and upward degradation. Additionally, due to strong solar radiation on the Tibetan Plateau and the main trend effect of the railway, difference in the thermal conditions of permafrost beneath embankment is considerable between the sunny and shady shoulders.

Key words: traditional embankment, permafrost, thermal stability, heat budget, Qinghai-Tibet Railway

中图分类号:

U416

穆彦虎, 马巍, 牛富俊, 李国玉, 王大雁, 刘永智. 青藏铁路多年冻土区普通路基热状况监测分析[J]. 冰川冻土, 2014, 36(4): 953-961.

MU Yanhu, MA Wei, NIU Fujun, LI Guoyu, WANG Dayan, LIU Yongzhi. Monitoring and analyzing the thermal conditions of traditional embankments along the Qinghai-Tibet Railway[J]. JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY, 2014, 36(4): 953-961.

参考文献

[1] Lunardini V J. Climatic warming and the degradation of warm permafrost[J]. Permafrost and Periglacial Processes, 1996, 7: 311-320.
[2] Cheng Guodong. Permafrost studies in the Qinghai-Tibet Plateau for road construction[J]. ASCE Journal of Cold Regions Engineering, 2005, 19(1): 19-29.
[3] Ma Wei, Liu Duan, Wu Qingbai. Monitoring and analysis of embankment deformation in permafrost regions of Qinghai-Tibet Railway[J]. Rock and Soil Mechanics, 2008, 29(3): 571-579. [马巍, 刘端, 吴青柏. 青藏铁路冻土路基变形监测与分析[J]. 岩土力学, 2008, 29(3): 571-579.]
[4] Ma Wei, Cheng Guodong, Wu Qingbai. Preliminary study on technology of cooling foundation in permafrost regions[J]. Journal of Glaciology and Geocryology, 2002, 24(5): 579-587. [马巍, 程国栋, 吴青柏. 多年冻土地区主动冷却地基方法研究[J]. 冰川冻土, 2002, 24(5): 579-587.]
[5] Cheng Guodong. Construction of Qinghai-Tibet Railway with cooled roadbed[J]. China Railway Science, 2003, 24(3): 1-4. [程国栋. 用冷却路基的方法修建青藏铁路[J]. 中国铁道科学, 2003, 24(3): 1-4.]
[6] Ma Wei, Cheng Guodong, Wu Qingbai. Construction on permafrost foundations: Lessons learned from the Qinghai-Tibet railroad[J]. Cold Regions Science and Technology, 2009, 59(1): 3-11.
[7] Wu Qingbai, Liu Yongzhi, Yu Hui. Analysis of the variations of permafrost under ordinary embankment along the Qinghai-Tibet Railway[J]. Journal of Glaciology and Geocryology, 2007, 29(6): 960-969. [吴青柏, 刘永智, 于晖. 青藏铁路普通路基下冻土变化分析[J]. 冰川冻土, 2007, 29(6): 960-969.]
[8] Zhang Jianming, Zhang Jinzhao, Liu Yongzhi. Study on the reasonable embankment height of Qinghai-Tibet Railway in permafrost regions[J]. China Railway Science, 2006, 27(5): 28-34. [张建明, 章金钊, 刘永智. 青藏铁路冻土路基合理路堤高度研究[J]. 中国铁道科学, 2006, 27(5): 28-34.]
[9] Yu Hui, Wu Qingbai, Zhang Jianming. Dynamic assessment of permafrost under ordinary embankment of Qinghai-Xizang Railway[J]. Journal of Engineering Geology, 2009, 17(1): 94-99. [于晖, 吴青柏, 张建明. 青藏铁路普通路基下冻土过程动态评价[J]. 工程地质学报, 2009, 17(1): 94-99.]
[10] Huang Mingkui, Wang Ren, Hu Mingjian. Analysis of thermal state under particle reformative roadbed in Qinghai-Tibet railway[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(23): 4390-4395. [黄明奎, 汪稔, 胡明鉴. 青藏铁路粒径改良路基热状况分析[J]. 岩石力学与工程学报, 2005, 24(23): 4390-4395.]
[11] Zhang Jianming, Liu Duan, Qi Jilin. Estimation on the settlement and deformation of embankment along Qinghai-Tibet Railway in permafrost regions[J]. China Railway Science, 2007, 28(3): 12-17. [张建明, 刘端, 齐吉琳. 青藏铁路冻土路基沉降变形预测[J]. 中国铁道科学, 2007, 28(3): 12-17.]
[12] Qin Yinghong, Zhang Jianming. Zhang Jianming. Estimating the stability of unprotected embankment in warm and ice-rich permafrost region[J]. Cold Regions Science and Technology, 2010, 61(1): 65-71.
[13] Mu Yanhu, Ma Wei, Liu Yongzhi, et al. Monitoring investigation on thermal stability of air-convection crushed-rock embankment[J]. Cold Regions Science and Technology, 2010, 62(2/3): 160-172.
[14] Liu Shiwei, Zhang Jianming. Review on physic-mechanical properties of warm frozen soil[J]. Journal of Glaciology and Geocryology, 2012, 34(1): 120-129. [刘世伟, 张建明. 高温冻土物理力学特性研究现状[J]. 冰川冻土, 2012, 34(1): 120-129.]
[15] Ma Wei, Mu Yanhu, Wu Qingbai, et al. Characteristics and mechanisms of embankment deformation along the Qinghai-Tibet Railway in permafrost regions[J]. Cold Regions Science and Technology, 2011, 67: 178-186.
[16] Jin Huijun, Zhao Lin, Wang Shaoling, et al. Thermal regimes and degradation modes of permafrost along the Qinghai-Tibet Highway[J]. Science in China (Series D: Earth Sciences), 2006, 49(11): 1170-1183.
[17] Yang Jianping, Yang Suiqiao, Li Man, et al. Vulnerability of frozen ground to climate change in China[J]. Journal of Glaciology and Geocryology, 2013, 35(6): 1436-1445. [杨建平, 杨岁桥, 李曼, 等. 中国冻土对气候变化的脆弱性[J]. 冰川冻土, 2013, 35(6): 1436-1445.]
[18] Wu Qingbai, Tong Changjiang. Permafrost change and stability of Qingimi-Xizang Plateau[J]. Journal of Glaciology and Geocryology, 1995, 17(4): 350-355. [吴青柏, 童长江. 冻土变化与青藏公路的稳定性问题[J]. 冰川冻土, 1995, 17(4): 350-355.]
[19] Tong Changjiang, Wu Qingbai. The effect of climate warming on Qinghai-Tibet Highway[J]. Cold Regions Science and Technology, 1996, 24(2): 101-106.
[20] Luo Dongliang, Jin Huijun, Lin Lin, et al. Degradation of permafrost and cold-environments on the interior and eastern Qinghai Plateau[J]. Journal of Glaciology and Geocryology, 2012, 34(3): 538-546. [罗栋梁, 金会军, 林琳, 等. 青海高原中、东部多年冻土及寒区环境退化[J]. 冰川冻土, 2012, 34(3): 538-546.]
[21] Yi Xin, Yu Wenbing, Chen Lin, et al. Influence of boundary conditions on the thermal stability of embankments in permafrost regions[J]. Journal of Glaciology and Geocryology, 2014, 36(2): 369-375. [易鑫, 喻文兵, 陈琳, 等. 边界条件对多年冻土路基热稳定性的影响分析[J]. 冰川冻土, 2014, 36(2): 369-375.]
[22] Chen Ji, Hu Zeyong, Dou Shun, et al. Yin-yang slope problem along Qinghai-Tibetan Lines and its radiation mechanism[J]. Cold Regions Science and Technology, 2006, 44(3): 217-224.