抛物线型屈服面人工冻土蠕变本构模型研究

利用自行研制的W3Z-200型冻土三轴压缩蠕变仪，对淮南地区深表土冻土进行了三轴蠕变试验。根据试验结果，提出以标准黏弹塑性模型为基础，并耦合温度自由度，应用抛物线型屈服准则对模型中的黏塑性项进行改进，建立了新的本构模型来描述高围压复杂应力状态下冻土的蠕变变形特征。基于ADINA有限元软件平台，开发了冻土本构子程序。对淮南某冻结井筒开挖过程进行了数值模拟，计算结果验证了冻土抛物线型黏弹塑本构模型的正确性和合理性。

Research on parabolic yield-surface creep constitutive model of artificial frozen soil

The triaxial creep experiment of artificial frozen soil in deep alluvium is performed by using self-developed a W3Z-200 apparatus of triaxial creep frozen soil.Analyzing the experiment results,applying parabolic yield criterion for improved viscoplasticity in the Nishihara model and coupling degree of temperature,a new creep constitutive model is established for describing frozen-soil's creep characteristics under the complicated stress state.The model is embedded in nonlinear ADINA finite element program in order to numerically analyze easily.Numerical simulation of the shaft well excavation process and field measurements of deformation of deep soil frozen wall are performed in Huainan Mine;and the results show that the established parabolic yield-surface constitutive model is correct and reasonable for FEM numerical simulation of deep soil frozen wall.