热-气-水-力耦合作用下非饱和土固结渗流机理与模型研究

考虑热-气-水-力耦合作用的非饱和土固结变形机理是应对低碳新能源开发和核废料安全处置面临的突出岩土工程问题，但现在没有一套系统的方法用于分析考虑温度场耦合作用的非饱和土固结变形。本项目拟通过研究热-气-水-力耦合作用的影响，建立一套系统的考虑超静孔隙水压与超静孔隙气压初始分布、时变边界、时变荷载的非饱和土一维、轴对称、二维平面应变固结模型。采用室内试验、理论推导、多物理场耦合数值分析、现场实测资料验证等研究方法，解决如下关键科学问题：1）揭示考虑温度场耦合作用的非饱和土固结过程中气液时空运移规律；2）建立考虑温度场耦合作用的非饱和土固结与土体热膨胀变形之间的关系，提出相应的非饱和土变形计算公式。研究成果可以弥补在温度场耦合作用下非饱和土变形研究缺乏的现状，为低碳新能源开发与核废料安全处置过程中的非饱和土变形问题提供科学依据与理论支撑。

The Thermo-Air-Hydro-Mechanical coupling effect in the consolidation of unsaturated soils is the key geotechnical problem in the development of low-carbon new energy and safety disposal of nuclear waste. However, no comprehensive methods exist for predicting the consolidation of unsaturated soils given the thermal coupling effect. Considering the Thermo-Air-Hydro-Mechanical coupling effect, this research aims to obtain a series of solutions for the one-dimensional, axisymmetric, and two-dimensional plane strain consolidation models of unsaturated soils associated with the initial excess pore pressure distributions, time-dependent semi-permeable boundaries, and time-dependent loading. By using the methodologies, such as, laboratory experiments, theoretical derivation, numerical analysis on basis of multi-physics coupling, and validation using field measurements, the following key scientific problems will be solved: 1) to reveal the tempo-spatial flows of the air and water phases during the consolidation process of unsaturated soils considering the Thermo-Air-Hydro-Mechanical coupling effect; 2) to establish mathematical relationship between the consolidation deformation and the soil expansion considering the coupled temperature field, and to propose the corresponding formulas for predicting the deformation of unsaturated soils. The research outcomes could supplement the consolidation theory of unsaturated soils considering the coupled temperature field and provide scientific basis and theoretical support for predicting the consolidation of unsaturated soils during the development of low-carbon new energy and safety disposal of nuclear waste.