季节性冻土隧道冻害机理分析及防冻探索

Frost Damage Mechanisms and Anti-Freezing Measures for Tunnels in a Seasonally Frozen Soil Region

在季节性冻土地区,新建隧道受温度、水、空隙等外界条件的影响,会在衬砌与围岩之间形成冻融圈。随着季节的变化,冻融圈在衬砌与围岩的约束下产生冻胀力,造成衬砌受损开裂,进而引发冻害。虽然我国学者针对冻胀机理与冻害影响因素进行了多年研究,完善了3种冻胀学说,并从微观和宏观层面提出多种防冻措施,但冻害问题仍然层出不穷。文章通过总结国内外季节性冻土地区隧道冻害现象、冻害机理及防冻措施,从温度、水、空隙等冻害必要条件出发,提出寒区隧道防冻减灾建议,以期对日后季节性冻土地区隧道的建设提供帮助。

Affected by temperature, water, crevices and other external conditions, a freeze-thaw cycle between the lining and surrounding rock may occur for a newly built tunnel in a region with seasonally frozen soil. With the change of seasons, the freeze-thaw cycle would produce frost heaves due to constraint of the lining and surrounding rock, causing lining cracking and freezing damage. Studies of the mechanism of frost heaves and the influential factors of frost damage have been conducted for many years, with three kinds of frost heave theory and a variety of antifreeze measures proposed from the micro and macro points of view; however, the problem of frost damage to tunnels in seasonally frozen regions still continues to occur. Countermeasures against freezing disasters in cold regions are presented by summarizing frost damage and analyzing the mechanism and measures for freeze prevention both at home and abroad in terms of temperature, water and crevices.