基于COD理论的岩石蠕变加速判别法探究

Study on creep acceleration discrimination method based on COD theory

基于弹塑性断裂力学理论,针对均匀岩石,假设裂纹均匀分布,建立理想裂纹单元体。结合断裂力学R–曲线理论和裂纹张开位移COD理论,提出岩石蠕变断裂过程的R–曲线理论。该曲线能合理解释岩石蠕变断裂全过程,并能有效获得蠕变状态变化的关键值;根据曲线特征,建立预测加速蠕变的控制方程;结合改进的岩石蠕变西原模型建立了新的岩石蠕变本构模型,可以很好地预测岩石加速蠕变发生过程,并用岩石蠕变试验验证预测方法的准确性,为深入研究脆性岩石蠕变断裂过程提供了理论依据。

Based on fracture mechanics theory,assuming that the crack is evenly distributed in the homogeneous rock,an ideal crack element is established.The R-curve theory of rock creep fracture process is put forward based on the R-curve theory of fracture mechanics and the crack opening displacement（COD） theory.By using this curve,the whole process of rock creep fracture can be reasonably revealed and the key parameters used to describe the status change of rock creep process are obtained.According to the characteristics of this curve,the control equation for predicting the accelerating creep of rock is established.Combined with the improved Nishihara creep model,A new rock creep model is established,which can accurately predict the accelerated creep process of rock and verify the accuracy of the prediction method with rock creep test.The theoretical basis for the intensive study of rock creep also provided by this model.