热-力耦合是当今岩土工程领域颇为关注的研究课题之一，是涉热岩土工程问题（如能源地下工程、放射性废料处置、输油及热力管道和热法地基处理等）的理论基础。经典土力学中有效应力原理描述了饱和土体在荷载作用下土骨架和孔隙流体之间的压力分布，但针对热-力耦合作用下土骨架及孔隙水之间的压力分布及其变化的研究罕有报道。该文从饱和土体宏观热固结响应出发，结合经典的有效应力原理，分析加热对土骨架和孔隙水的影响，推导考虑温度影响的有效应力和孔隙水压力表达式，建立考虑温度影响的饱和土有效应力原理，探讨不同位移边界和排水边界条件下有效应力和孔隙水压力的分布变化。结果发现：在热-力耦合作用下，土体的总应力、超静孔隙水压力和有效应力均随温度变化而变化；加热引起的温度应力和热孔压随时间变化而变化，影响土体的压缩性和强度，并进一步影响固结压缩过程和压缩量。该研究结果可为热固结理论推导及其他涉热岩土工程问题分析提供技术支撑。
Thermo-mechanical coupling is a key research topic in geotechnical engineering today for solving thermal geotechnical engineering problems, including underground energy engineering projects, radioactive waste disposal, oil transport and thermal pipelines, and thermal soft ground stabilization methods. The classical principle of the effective stress in soil mechanics describes the pressure distribution between the soil skeleton and the pore fluid for saturated soil. However, the pressure distribution and its changes between the soil skeleton and the pore water with thermal-mechanical coupling have rarely been reported. This study combines the macroscopic thermal response of the soil consolidation with the classical effective stress principle to analyze the influence of heating on the soil skeleton and the pore water to develop an effective stress and pore pressure prediction formula that includes the influence of temperature. The effective stress principle considering the temperature effect is used to analyze the effective stress and pore pressure distributions for various displacement and drainage boundary conditions. The results show that the thermo-mechanical coupling affects the total stress, the excess pore water pressure and the effective stress in the soil. The temperature stress and the thermal excess pore pressure caused by heating change with time and affect the soil consolidation and compression. The thermal stresses affect the soil stress state and indirectly affect the soil compressibility and strength. The research results can be used to develop thermal consolidation theory and to analyze problems related to thermal geotechnical engineering.
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