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寒区含表面裂隙硬岩与大气连通,易受外界低温环境引起裂隙内部水分凝结,造成裂隙带附近形成温度场突变,进而随水冰相变产生冻胀力,二者随着冻结活动处于动态演化之中,涉及到温度场、渗流场及应力场等多场问题。目前的研究大多依据数值模拟结果,描述裂隙岩体温度场、应力场分布特征及规律,考虑从基础理论解析计算角度,探究低温环境下裂隙岩体温度场、冻胀力演化规律鲜有报道。针对含表面裂隙硬岩在低温环境下发生的冻结现象,从传热学理论、相变理论、弹塑性力学及断裂力学理论等多角度出发,探讨随着冻结深入含表面裂隙硬岩内部温度场及冻胀荷载演化过程,提出对应解析表达式,引入多场耦合数值程序Comsol-Multiphysics进行数值模拟验证,结果表明,文中提出的温度场及冻胀荷载演化解析表达式与数值模拟结果具有较好吻合度,可满足对含表面裂隙半无限板模型温度场、应力场演化过程分析,对于裂隙岩体在低温环境下温度场、应力场演化及热-力耦合分析具有较好借鉴价值。
Cold hard rock with surface fissures connected with the atmosphere, vulnerable to external low temperature environment caused by condensation of water within the fracture, resulting in sudden changes in the temperature field near the fracture zone, and then with the ice-water phase transition to produce frost heaving, both with the freezing activity in a dynamic Evolution, involving the temperature field, seepage field and stress field and many other issues. Most of the current researches mainly describe the distribution characteristics and laws of temperature and stress field of fractured rock mass based on the numerical simulation results. Considering the analysis and calculation of basic rock theory, the evolution of temperature field and frost heave force of fractured rock mass are rarely reported. Aiming at the freezing phenomenon of hard rock with surface fracture at low temperature, this paper discusses the internal temperature field of frozen hard rock with surface crack in depth from the aspects of heat transfer theory, phase transition theory, elasto-plasticity mechanics and fracture mechanics theory. And the evolution process of frost heave expansion load, the corresponding analytical expressions are proposed and the multi-field coupled numerical program Comsol-Multiphysics is used to verify the numerical simulation. The results show that the analytical expressions and numerical simulations of the evolution of temperature field and frost heave load presented in this paper are well The fitting degree can satisfy the analysis of the evolution process of temperature field and stress field in the semi-infinite plate with surface fissure, which is of good reference value for the temperature field and stress field evolution and thermo-mechanical coupling analysis of fractured rock mass in low temperature environment.