基于西原加速模型的煤体蠕变特性试验

为克服传统西原模型无法描述煤体加速蠕变特征的缺陷，针对煤体加速蠕变阶段中黏-弹-塑性流动特征，利用一个非线性的黏-弹-塑性模型来代替传统西原体模型中的理想黏-塑体，得到改进的西原加速模型，并推导该模型在等围压三轴条件下的蠕变方程。通过开展煤样三轴蠕变试验，采用模型辨识的方法，利用改进的西原加速蠕变模型对煤体蠕变试验数据进行了拟合分析。结果表明，拟合结果与试验数据基本吻合，较好地反映出了煤体非衰减蠕变特征；并对改进模型的稳定性进行讨论，加速蠕变模型中的弹性模量E₃具有明确的物理意义，可将E₃<0作为煤体发生蠕变失稳的判断依据。 

Nishihara acceleration model-based experiment of creep characteristics of coal

For conquering limitation that the traditional Nishihara model cannot describe the accelerated creep characteristics of coal body, according to the visco-elastic-plastic flow characteristics of coal in the accelerated creep stage, a nonlinear visco-elastic-plastic model was used to replace the ideal viscoelastic-plastic body in Nishihara model to establish the improved Nishihara acceleration model. And creep equation of the improved model under equal confining pressure triaxial condition was also deduced. Afterwards, the improved accelerated creep model was analyzed by the creep test data of coal specimens in the triaxial creep tests using the method of model identification. The results show that the fitting results are basically consistent with the test data, which can preferably reflect non-decay creep characteristics of coal. In addition, the stability of the improved model was also analyzed, the parameter E₃ has clear physical significance, and E₃ < 0 can be used as the basis for judging creep instability of coal.