A rheological constitutive model for damaged zone evolution of a tunnel is proposed in this paper to describe the strain hardening and softening properties of the excavation-disturbed rock mass. Firstly, the one-dimension rheological model is introduced by connecting the improved St. Venant body with the Nishihara model, and this model can be used to describe the whole process including transient viscoplastic creep under a low-stress state, steady-state and accelerative creep under a high-stress state. Secondly, the constitutive equations of the rheological model under three-dimensional condition of the improved St. Venant body based on generalized plasticity potential theory are deduced, and the generic three-dimensional rheological model is developed. Thirdly, the creep and stress relaxation properties of the rheological model are studied and discussed. Furthermore, numerical analysis of triaxial compression tests and triaxial compression creep tests are conducted and the rheological model are validated. The results show that the rheological model can be used to study the evolution of excavation damaged zone in underground tunnel engineering.

提出了隧道破坏带演化的流变本构模型，描述了开挖扰动岩体的应变硬化和软化特性。首先，将改进的St. Venant体与Nishihara模型相连接，引入一维流变模型，该模型可用于描述包括低应力状态，稳态和加速状态下的瞬态粘塑性蠕变的整个过程。在高应力状态下蠕变。其次，基于广义可塑性势理论，推导了改进的圣维南体在三维条件下的流变模型的本构方程，建立了通用的三维流变模型。第三，研究和讨论了流变模型的蠕变和应力松弛特性。此外，进行了三轴压缩试验和三轴压缩蠕变试验的数值分析，并验证了流变模型。结果表明，流变模型可用于研究地下隧道工程开挖损伤带的演化。