Abstract:Abstract:Research purposes: Frost heaving and thaw settlement of permafrost have great influence on engineering construction. The Lenglongling of Qilian Mountains is an area with high altitude and extremely cold climate. And the permafrost is distributed above 3400 m elevation from related articles. The 2nd Lanzhou-Xinjiang Railway crosses the Lenglongling by tunnel group, and the elevation of each tunnel entrance of northern slope is all lower than 3400 meters. Finding out the permafrost lower bound and the engineering characteristics of the permafrost are of great significance for the tunnel design and construction safety.
Research conclusions:(1) The research shows that the permafrost lower bound in elevation of the north slope of Qlilian Mountains is between 3170~3390 meters, the thickness of the permafrost is between 0~23 meters, and the ground temperature is between -0.05~0.05 ℃. It belongs to extreme instability regions. (2) The distribution of permafrost is closely related to the lithology, water content, air temperature, ground temperature, slope aspect, vegetation, etc. The exit section on shade slope of each tunnel has patchy permafrost, but the entrance section on sunny slope has no distribution. (3) According to the characteristic of permafrost, the relevant engineering adopted the corresponding treatment scheme. (4) The conclusion that the correction and the engineering characteristics of the permafrost lower bound has reference significance for similar engineering construction.
尹鸿远. 祁连山北麓多年冻土特征及工程处理措施[J]. 铁道工程学报, 2015, 32(4): 21-.
YIN Hong-yuan. The Charateristics of Permafrost on the Northern Slope of Qilian Mountains and Its Engineering Treatment Measures. 铁道工程学报, 2015, 32(4): 21-.
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