|
|
|
| Application of Thermal Probe Group in Protection of Shallow Section of Tunnel in Permafrost Area |
| LIU Kun, CAI Han-cheng, LI Fen |
| Northwest Research Institute Co. Ltd of CREC, Lanzhou, Gansu 730000, China |
|
|
|
|
Abstract Research purposes: The environment temperature of the structure in shallow section of the tunnel in the permafrost area is mainly influenced by the atmospheric temperature. The water above frozen layer is easy to converge around the tunnel opening because of the large amplitude of change of temperature and the thawing circle caused by construction approaching to or overlapping the top limit of permafrost during the construction. Therefore, the damage phenomena like lining cracking, water leakage and ice covering easily happen to the parts of the tunnel in such area. The possible damage to the supporting structure for the tunnel caused by the freezing and thawing cycle can be reduced or avoided by using the active cooling protection for the surrounding wall in the tunnel shallow section in permafrost area.
Research conclusions:(1) By using the thermal probe group, the temperature of the surrounding wall will be significantly reduced within its sphere of influence, the strength of the surrounding wall of permafrost will be enhanced, and the top limit of the permafrost will be raised to form a waterproof curtain on the tunnel ceiling for reducing the frost heaving force on the tunnel supporting structure.(2)The water above frozen layer can’t infiltrate into the tunnel structure and the refreezing time will be reduced from 3 to 5 freezing and thawing cycles to 1 cycle. In this way, the problem of the freeze-thawing damage to the supporting structure in the portal section can be solved.(3)This technology has features of lower engineering cost and more convenience in terms of installing and monitoring. (4)This research achievement can be used for the disease control and treatment of the shallow section of tunnel in the permafrost area.
|
|
Received: 23 May 2013
|
|
|
|
|
|
[1]秦大河.中国西部环境演变评估[M].北京:科学出版社,2002.
Qin Dahe. Assessment of Environmental Evolution in Western China[M]. Beijing: Science Press, 2002:20-22.
[2]丁靖康, 等.多年冻土与铁路工程[M].北京:中国铁道出版社,2011.
Ding Jingkang. Permafrost and Railway Engineering[M]. Beijing: China Railway Press, 2011:9-10.
[3]徐教祖, 等.冻土物理学[M].北京:科学出版社,2010.
Xu Xiaozu. Physics of Frozen Soils[M]. Beijing: Science Press, 2010.
[4]丁靖康.冻土地区热桩技术的应用[R].兰州:中铁西北科学研究院,1990.
Ding Jingkang. Application of Permafrost Thermal Pile Technology[R]. Northwest Research Institute Co. LTD of C. R. E. C. ,1990.
[5]庄骏, 等.热棒技术及其工程应用[M].北京:化学工业出版社, 2000.
Zhuang Jun, etc. Heat Pipe Technology and Its Application in Engineering[M]. Chemical Industry Press,2000.
[6]陈肖柏, 等.土的冻结作用与地基[M].北京:科学出版社,2006.
Chen Xiaobo, etc. The Role of Soil Freezing and Foundation[M]. Beijing: Science Press, 2006.
[7]徐兵魁, 熊治文.青藏高原多年冻土区热棒路基的设计计算[J].中国铁道科学,2006(5):89-92.
Xu Bingkui, Xiong Zhiwen. Permafrost Regions Hot Rod Embankment Design Calculations[J]. China Railway Science, 2006(5):89-92.
[8]牛东兴, 李勇, 熊治文, 等.青藏铁路多年冻土区热棒路基地温场分析[J].铁道工程学报,2012(9):30-33.
Niu Dongxing, Li Yong, Xiong Zhiwen, etc. Tibet Railway Permafrost Ground Temperature Hot Rod Field Analysis [J]. Journal of Railway Engineering, 2012(9):30-33.
|
|
|
|
2013, Vol. 30 
