摘要
田桓铁路大前石岭隧道进口发现岛状多年冻土,该区域现在不具有发育多年冻土的气候、地理条件。根据对研究区的冰缘地貌现象分析,并对冻土采用不平衡U系法测年得知该冻土非现在气候条件下形成,而是形成于晚更新世末次冰期冰盛期,年龄为(12 279±79)年。现场对冻层测温表明该冻土是由于表面块石层气冷作用得以保持其热稳定性并保存至今,冻土表面7 m厚的块石层气冷作用使冻土温度平均降低约1.5℃。开挖可能会破坏现有的热平衡体系,建议减少表层块石、碎石层的开挖。冻土测温加冻冰测年的方法为类似冻土研究提供了借鉴和参考,本研究成果可为田桓铁路建设提供了重要参数。
Island-shape permafrost is discovered in Daqianshiling tunnel entrance section of Tianshifu-Huanren railway,but there is no climatic and geographical conditions for the formation of permafrost in this area.By analysis of periglacial geomorphology in research area and Uranium series dating on the permafrost,the permafrost with the age of(12 279±79)a is proved to be non-modern climate products and formed in the late Pleistocene LMG.The air conversion effect of the 7 m thick surface ballast layer which decreased the temperature by 1.5℃averagely is proved to be the preservation cause for the permafrost through temperature measuring in the field.The existing heat balance system might be destroyed by excavation.It is recommended to reduce the excavation to the stone and gravel layer.Some references are provided for similar permafrost by temperature measurement and dating.The research results will be great meaningful parameters to guide the construction of the railway.
作者
伍运霖
刘天翔
邓清禄
雷航
WU Yun-lin;LIU Tian-xiang;DENG Qing-lu;LEI Hang(Survey,Design and Research Institute,Sichaun Provincial Transport Department Highway Planning,Chendu 610000,China;Faculty of Engineering,China University of Geosciences,Wuhan 430074,China)
出处
《科学技术与工程》
北大核心
2019年第27期107-112,共6页
Science Technology and Engineering
基金
交通运输部建设科技项目(2013318800020)
四川省交通科技项目(2013A1-3,2012C14-2)资助
关键词
多年冻土
冰缘地貌
末次冰盛期
气冷作用
permafrost
periglacial geomorphology
the last glacial maximum
air conversion effect
