岩石非线性黏弹塑性蠕变模型研究

Investigation on nonlinear viscoelasto-plastic creep model of rocks

为了全面描述岩石蠕变的全过程,将非线性黏塑性模型与Burgers模型串联组成一个新的六元件非线性黏弹塑性蠕变模型。在黏塑性模型的蠕变量与时间呈幂函数关系的情况下,该蠕变模型可以很好地反映岩石的加速蠕变特性。利用已有文献对长山盐矿进行的单轴压缩蠕变试验结果,对所建立的非线性黏弹塑性蠕变模型的六个蠕变参数进行识别,所得结果与试验结果拟合度在0.959以上,表明了本文所建立的岩石非线性黏弹塑性蠕变模型的合理性与正确性。

In order to describe the whole process of a rock creep comprehensively,a new nonlinear visco-elasto-plastic creep model of six elements is constructed by combining the nonlinear visco-plastic model with the Burgers model.In the case that the creep variables of the visco-plastic model are power-function with time,the creep model can fully reflect the accelerated creep characteristics of the rock.Based on the uniaxial compression creep test results of Changshan Salt Mine by related literatures,the six creep parameters of the nonlinear visco-elasto-plastic creep model are identified,and the fitting degree of model and test is over 0.959,which indicates that the nonlinear visco-elasto-plastic creep model established in this paper is correct and reasonable.