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岩体在冻融循环下裂隙中会经历冻胀力的萌生、发展与消散,裂隙冻胀扩展和岩体冻胀损伤程度受冻胀力控制,基于热力学、渗流理论、界面力学和弹性理论建立了柱形封闭裂隙中冻胀力演化模型,对考虑水分迁移和不迁移两种情况下的冻胀力量值进行了研究。结果表明:不考虑水分迁移作用下冻胀力随裂隙饱和度g和岩石弹性模量sE增加而迅速增大,当sE>10 GPa且g>94%时产生的冻胀力超过15 MPa,足以驱动任何岩体冻胀开裂,不同岩石裂隙冻胀开裂存在一个对应的临界饱和度ming;考虑岩石的透水性,渗透率低于5×10~(-14) cm~2的低渗透性岩石中裂隙水冻结会产生较大的冻胀水压力,容易引起裂隙冻胀扩展;而在渗透率大于10~(-12) cm~2的高渗透性岩石中,饱和裂隙水冻结难以形成有害的冻胀水压,裂隙冻胀开裂主要是冻结后期在冰-岩界面间的微观未冻水膜中产生的分离压力引起。
The rock mass undergoes the initiation, development and dissipation of frost heave force in the fissures during the freeze-thaw cycles, and the frost heave expansion and the degree of frost heave expansion are controlled by the frost heave force. Based on the thermodynamics, seepage theory, interface mechanics and elasticity theory The evolution model of frost heave force in cylindrical closed fractures was studied, and the frost heave force values under both cases of water migration and non-migration were studied. The results show that the frost heaving force increases rapidly with the increase of fracture saturation g and elastic modulus sE without considering the effect of water migration. When sE> 10 GPa and g> 94%, the frost heaving force exceeds 15 MPa, which is enough For any rock mass subjected to frost heaving and cracking, there is a corresponding critical saturation ming for the frost heave and fissure of different rock fractures. Considering the water permeability of the rock, the permeability is lower than 5 × 10 ~ (-14) cm ~ 2 in low permeability rocks Frozen water in fissure water will generate large frost heaving pressure, which will easily lead to frost heave expansion. In highly permeable rocks with permeability greater than 10 ~ (-12) cm ~ 2, it is difficult to form harmful frozen frost Water pressure and crack frost heave cracking are mainly caused by the separation pressure in the microscopic unfrozen water film at the ice-rock interface in the late stage of freezing.