Unsaturated thermal consolidation around a heat source
Unsaturated thermal consolidation around a heat source
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DOI：
10.1016/j.compgeo.2021.104091
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发表时间：
2021-06
影响因子：
5.3
通讯作者：
Davood Yazdani Cherati;Omid Ghasemi-Fare
中科院分区：
文献类型：
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作者：
Davood Yazdani Cherati;Omid Ghasemi-Fare
由于孔隙体积和孔隙水的热膨胀系数的差异，饱和（两相）粘土中的热载荷引起超孔隙水压力。超孔隙水压力的逐渐消散引起热体积减小，这被称为热固结。然而，在三相土壤系统，如非饱和土的热固结是更复杂的。本文基于有效应力的概念，建立了非饱和粘土或含两种不互溶流体的粘性土中热源周围的热固结分析模型。控制方程，包括能量，质量和动量平衡方程。共存的固体和孔隙流体被假定为处于局部热平衡。首先，通过考虑常系数，使用傅立叶-拉普拉斯变换提供解决方案。逆变换进行了充分的分析，因此，提出了一个封闭形式的解决方案。然后，通过时间离散化过程，考虑了热固结过程中土性的变化。利用绿色函数理论对所建立的模型进行了验证，并将方程和结果与文献中的模型进行了比较。结果表明，该模型能够准确地预测在三相粘性土的热固结。
Thermal loadings in saturated (two-phase) clays induce excess pore water pressure due to the difference in the thermal expansion coefficient of the pore volume and the pore water. The gradual dissipation of the excess pore water pressure causes thermal volume reduction which is known as thermal consolidation. However, thermal consolidation in a three-phase soil system such as unsaturated soil is more sophisticated. In this paper, an analytical model for thermal consolidation around a heat source embedded in unsaturated clay or in calyey soils containing two immiscible fluids is developed based on the effective stress concept. Governing equations, including energy, mass, and momentum balance equations are developed. Coexisting solid and pore fluids are assumed to be in local thermal equilibrium. First, a solution is provided using Fourier-Laplace transformation by considering constant coefficients. The inverse transformation is carried out fully analytically and thus, a closed-form solution is proposed. Then, the variations of soil properties during the thermal consolidation process are considered through a temporal discretization process. The developed model is validated using Green’s function theory and the equations and results are compared with the available models in the literature. Results indicate the capability of the model to accurately predict thermal consolidation in a three-phase clayey soil.