The formulation of a new thermo-mechanical constitutive model consistent with the principles of thermodynamics is presented. The model is capable of predicting the rate-independent thermo-mechanical behavior of fine-grained soils. The constitutive equations are derived by defining only a Gibbs-type free energy and a dissipation potential, in accordance with the hyperplasticity method. The addition of thermo-elasticity to the energy potential, and the embedding of the identified thermo-mechanical mechanisms into a newly proposed dissipation potential, enables the model to describe the thermo-mechanical behavior. The proposed dissipation potential eliminates the application of shift stress, which results in a simpler formulation in the context of hyperplasticity. The step-by-step procedure of deriving the equations, as well as a detailed analysis of the parameters of the model, is presented. The performance of the model is shown to be in good agreement with experimental data. A qualitative description of the possible micro-scale mechanisms for fine-grained soils, when subjected to temperature variation, is presented, as a step towards including the mechanisms in the formulation.

提出了一种符合热力学原理的新型热机械本构模型。该模型能够预测与速率无关的细粒土的热力学行为。根据超塑性方法，通过仅定义吉布斯型自由能和耗散势导出本构方程。将热弹性添加到能势中，并将已识别的热机械机制嵌入到新提出的耗散势中，使模型能够描述热机械行为。所提出的耗散势消除了位移应力的应用，从而在超塑性的情况下产生了更简单的公式。推导方程的逐步过程，以及对模型参数的详细分析。模型的性能与实验数据非常吻合。提出了对细粒土壤可能的微观尺度机制的定性描述，当受到温度变化时，作为将这些机制包含在公式中的一步。