Finite element analyses of rate-dependent thermo-hydro-mechanical behaviors of clayey soils based on thermodynamics
Finite element analyses of rate-dependent thermo-hydro-mechanical behaviors of clayey soils based on thermodynamics
复制标题
基于热力学的粘土速率相关热水力学行为的有限元分析
DOI：
10.1007/s11440-020-01125-1
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发表时间：
2021-01
期刊：
影响因子：
5.7
通讯作者：
Jian Chu
中科院分区：
文献类型：
--
作者：
Hao Wang;Xiaohui Cheng;Jian Chu
能源地质结构附近的粘土可能会暴露于长期周期性的热循环。粘性土的蠕变和固结特性既与速率有关，又与温度有关，其物理机制目前仅从理论上研究。本文基于热力学理论，编制了一个饱和土热-水-力耦合有限元程序。FE公式通过颗粒温度的新概念考虑了速率和温度的综合影响。模拟THM耦合验证的情况下，一系列的实验观察软曼谷粘土进行。所得的数值结果与解析解和实验测量结果吻合较好。结果表明，正常固结和轻度超固结粘土在排水热循环条件下的不可逆热收缩主要由三种基本物理机制引起：（1）吸附水向自由水的质量交换引起的热蠕变;（2）围压引起的机械蠕变;（3）土颗粒热膨胀引起的颗粒堆积增加。由于热蠕变速率的显著降低，热收缩通常在几个热循环内稳定。进一步证明了瞬态传热和升温速率对热循环下粘土的变形有很大影响。
Clayey soils in the vicinity of energy geostructures may be exposed to long-term periodic thermal cycles. The creep and consolidation behaviors of the clayey soils can be both rate-dependent and temperature-dependent, and the underlying physical mechanisms are merely investigated theoretically. In this study, based on the theory of thermodynamics, a fully coupled thermo-hydro-mechanical (THM) finite element (FE) program for saturated soils is developed for this purpose. The FE formulation accounts for the combined effect of rate and temperature through the novel concept of granular temperature. Simulations of THM coupled validation cases and a series of experimental observations on the soft Bangkok clay are carried out. The obtained numerical results exhibit good agreement with analytical solutions and laboratory measurements. It is found that three fundamental physical mechanisms contribute to the irreversible thermal contraction observed for normally consolidated and lightly overconsolidated clays under drained thermal cycles: (1) the thermal creep excited by mass exchange from adsorbed water to free water; (2) the mechanical creep induced by confining stresses; and (3) the increase in granular packing caused by the thermal expansion of soil particles. The thermal contraction generally stabilizes within a few thermal cycles, as a result of the noticeable reduction in the thermal creep rate. It is further demonstrated that the transient heat transfer and the heating rate can greatly influence the deformation of clays subjected to thermal cycles.
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DOI：
10.1002/nag.2569
发表时间：
2017-03
影响因子：
4
作者：
Zhichao Zhang;Zhichao Zhang;Xiaohui Cheng
通讯作者：
Zhichao Zhang;Zhichao Zhang;Xiaohui Cheng
DOI：
10.1007/978-3-319-52773-4_56
发表时间：
2017-01
期刊：
--
影响因子：
--
作者：
Hao Wang;Xiaohui Cheng
通讯作者：
Hao Wang;Xiaohui Cheng
影响因子：
6.4
作者：
K. Ochsner
通讯作者：
K. Ochsner
影响因子：
7.4
作者：
H. Abuel-Naga;D. Bergado;A. Bouazza
通讯作者：
H. Abuel-Naga;D. Bergado;A. Bouazza
影响因子：
3.6
作者：
H. Abuel-Naga;D. Bergado;A. Bouazza;G. Ramana
通讯作者：
H. Abuel-Naga;D. Bergado;A. Bouazza;G. Ramana