A fully coupled THM model based on a non‐equilibrium thermodynamic approach and its application
A fully coupled THM model based on a non‐equilibrium thermodynamic approach and its application
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DOI：
10.1002/nag.2569
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发表时间：
2017-03
影响因子：
4
通讯作者：
Zhichao Zhang;Zhichao Zhang;Xiaohui Cheng
中科院分区：
文献类型：
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作者：
Zhichao Zhang;Zhichao Zhang;Xiaohui Cheng
在这项研究中，一个完全耦合的热-水-力学（THM）理论模型，称为清华-热土模型，适用于饱和土壤，是基于非平衡热力学方法（见Groot S，Mazur P.非平衡热力学。阿姆斯特丹：北荷兰酒吧。有限公司、1962年）。该模型通过非平衡热力学理论将THM耦合系统的数学描述简化为一组迁移系数和能量函数的建模。引入了颗粒熵的重要概念来描述颗粒的涨落和由此产生的瞬态弹性。因此，非弹性力学本构关系，不需要这样的概念，如屈服面和流动法则。考虑温度升高时束缚孔隙水转化为自由水的物理过程，描述了正常固结和轻度超固结粘土在非等温条件下的体积压缩现象。利用该模型对不同超固结比的饱和高岭土在不同温度下的热固结和排水剪切试验进行了数值模拟。分析了OCR值、升温速率和温度循环对热固结的影响以及温度对抗剪强度的影响，并与已有的试验数据进行了对比。结果表明，本文提出的模型能较准确地描述饱和土的热固结和剪切基本规律，初步证明了模型的有效性。版权所有© 2016约翰威利父子有限公司.
In this study, a fully coupled thermo‐hydro‐mechanical (THM) theoretical model, called the TSINGHUA‐THERMOSOIL model, which is applicable in saturated soils, was developed based on a non‐equilibrium thermodynamic approach (see Groot S, Mazur P. Non‐Equilibrium thermodynamics. Amsterdam: North‐Holland Pub. Co., 1962). This model simplifies the mathematical description of a THM coupling system to the modeling of a group of migration coefficients and energy functions by means of the non‐equilibrium thermodynamic theory. The important concept of granular entropy was introduced for describing the granular fluctuation and the resulting transient elasticity. Therefore, non‐elastic mechanical constitutive relations that do not require such concepts as yield surface and flow rule are obtained. The physical process of bound pore water transforming into free water when the temperature rises was taken into consideration for describing the phenomenon of the volumetric compression of normally consolidated and slightly over‐consolidated clays under non‐isothermal conditions. The behavior of thermal consolidation and drained shear tests at different temperatures for saturated Kaolin clay with different over‐consolidation ratios (OCR) were simulated using this model. The effect of the OCR value, the heating rate and temperature cycling on the thermal consolidation and the effect of the temperature on the shear strength were analyzed and compared with existing experimental data. The results showed that the model proposed in this paper can accurately describe the thermal consolidation and the basic law of shearing for saturated soil, which preliminarily proves the validity of the model. Copyright © 2016 John Wiley & Sons, Ltd.