超固结土热黏弹塑性本构关系

热黏弹塑性本构模型是描述土在温度（热）和时间（黏）耦合作用下的应力-应变关系的本构模型。在一些新型岩土工程诸如高放核废料地质处置、地热资源开发与贮存的建设中，需要同时考虑温度和时间对土的影响，所以建立一个热黏弹塑性本构模型具有理论和实际意义。将温度变化对黏土体积和强度参数的影响引入笔者之前提出的超固结土等向应力-应变-时间关系，建立了一个等向应力条件下的应力-应变-时间-温度关系。随后，基于该关系推导了屈服面硬化定律，并将其与超固结土统一硬化模型的屈服方程和流动法则结合，建立了超固结土的热黏弹塑性本构模型。最后，使用新模型预测室内试验，证明新模型能够反映时间和温度对土体积、一维压缩曲线和前期固结压力的耦合影响。

Thermo-visco-elastoplastic constitutive relation for overconsolidated clay

The thermo-visco-elasto-plastic constitutive model describe the stress-strain relationship of soil under the combined effect of temperature and time. In the construction of some new-type geotechnical engineering, such as nuclear waste disposal as well as geothermal extraction and storage, it is necessary to consider the influences of both temperature and time. Therefore, it is theoretically and practically meaningful to establish a thermo-visco-elastoplastic constitutive model. Firstly, an isotropic stress-strain-time- temperature relation is established by considering the temperature effect on clay volume and strength parameter into the isotropic stress-strain-time relation. Afterwards, hardening rules are deduced from the isotropic stress-strain-time-temperature relation. Through combining the hardening rules with the yield functions of the unified hardening constitutive model, a thermo-visco- elastoplastic constitutive model for overconsolidated clay is proposed. Finally, the proposed model is used to predict laboratory tests. The predicted results show that the proposed model can describe the combined effect of temperature and time on the clay volume, the isotropic compression curve and the preconsolidation pressure.