青藏铁路昆仑山隧道洞内气温及地温分布特征现场试验研究

在昆仑山隧道洞内设置了地温及气温观测断面。根据实测资料,初步分析了昆仑山隧道洞内气温、地温及隔热层内外侧温度分布特征,得出的结论对多年冻土区隧道工程建设及冻害防治有一定的指导意义。

FIELD EXPERIMENT ON DISTRIBUTION CHARACTERS OF AIR TEMPERATURE AND GROUND TEMPERATURE IN KUNLUNSHAN TUNNEL OF QINGHAI-TIBET RAILWAY

Several sections were set up to observe the air temperature and ground temperature in Kunlunshan tunnel. Based on the observed data,the distribution characters of the air temperature,ground temperature,and temperature on two sides of an insulation layer in this tunnel,were analyzed. It is found that (1) air temperature on the top is higher than that on the bottom of the tunnel,and air temperature is lower at the end of tunnel than that in the center of the tunnel. The influence of air temperature outside tunnel gradually becomes weaker as the distance from entrance and exit increasing;(2) ground temperature linearly decreases with the depth along surrounding rocks increasing and it becomes negative at a certain depth;(3) the thawed areas appear in the rocks surrounding the tunnel after excavation and the thickness of thawed areas is mainly influenced by air temperature;and (4) the effect of thermal insulation of insulation layer is good for tunnel in cold regions.