寒区隧道冻胀力计算方法研究进展与思考

近年来，随着中国西部及青藏高原地区交通网的建设，修建了越来越多的寒区隧道，然而寒区隧道冻害也频繁发生。隧道冻胀力计算是寒区隧道防抗冻设计亟待解决的难题之一。首先将现有的冻胀力计算方法分为基于含水风化层冻胀模型、衬砌背后积水冻胀模型、冻融圈整体冻胀模型3类。含水风化层冻胀模型利用侧压力代替冻胀力作用，衬砌背后积水冻胀模型将冻胀力归结于衬砌与围岩之间的局部积水冻结膨胀，冻融圈整体冻胀模型则认为冻胀力系冻融圈围岩含水冻结后整体膨胀所致。然后对这些方法及其基于的假定与适用性进行了系统的分析和总结。最后重点分析了基于冻融圈整体冻胀模型的冻胀力计算方法，并归纳出3种考虑冻融圈冻胀变形的方式：①假定冻结圈冻胀位移模式；②假定冻结圈围岩各向均匀冻胀；③考虑冻结圈围岩非各向均匀冻胀。剖析了不同冻融圈冻胀变形处理方法的区别和联系，并通过工程案例对比分析了不同冻融圈冻胀变形处理方法对冻胀力计算结果的影响，分析了考虑围岩非各向均匀冻胀时冻胀力解的适用性。研究结论可为寒区隧道工程设计提供借鉴。

Advance and Review on Frost Heaving Force Calculation Methods in Cold Region Tunnels

In recent decades, numerous cold region tunnels have been constructed as the development of the transport network in West China and the Tibetan Plateau. However, frost damage occurs frequently in these tunnels. To prevent the frost damage, calculation of the frost heaving force is a problem that needs to be solved with some urgency. This paper provides a review of existing frost heaving force calculation methods. These methods are based on three kinds of frost heave models:the water-bearing weathering layer model, water space frost heave model, and freeze-thaw circle frost heave model. The frost heaving force is equivalent to the lateral pressure in the water-bearing weathering layer model, whereas in the water space frost heave model, the frost heaving force is attributed to the freezing and expansion of water in the local area between the lining and the surrounding rock. Moreover, the frost heaving force is caused by the freezing and expansion of the freeze-thaw circle for the freeze-thaw circle frost heave model. The applicability and drawbacks of the methods and their assumptions were summarized and clarified. Moreover, the frost heaving force calculation methods based on the freeze-thaw circle frost heave model were thoroughly analyzed and categorized into three cases:① subjectively assuming the frost heave displacement mode of the freeze-thaw circle, ② assuming that the frost heave of the freeze-thaw circle is isotropic, and ③ assuming that the frost heave of the freeze-thaw circle is anisotropic. The differences and connections of the three cases were specified. In addition, the methods based on the freeze-thaw circle frost heave model were compared through an actual engineering case, and the rationality of the frost heaving force calculation method considering the anisotropic frost heave of surrounding rock was analyzed.