深部岩石统计损伤本构模型研究

A study of statistical damage constitutive models for deep earth rocks

为建立能够反映深部岩石变形全过程模拟方法,首先,针对强度准则的适用性条件建立了深部岩石强度准则,并在此基础上提出了深部岩石微元强度度量方式,同时,引入统计损伤理论,考虑损伤阀值对岩石损伤度量的影响,从而建立了统计损伤本构模型;其次,根据岩石三轴试验曲线特征给出了模型参数的确定方法,并在峰值应力和峰值应变分别与围压之间的关系基础上,建立了能够反映不同围压下岩石变形的统计损伤本构模型;最后,将试验曲线与本文模型的预测结果进行比较分析。研究结果表明:本文模型不仅能够反映深部岩石的变形过程,还能较好地反映岩石强度随围压变化的特性,表明了本文模型与方法具有一定的合理性和可行性。

To establish the full process simulation method of deep earth rocks deformation,deep earth rocks strength criterion was built aiming at the applicability conditions of rock strength criterion and the corresponding micro-unit strength measurement method was put forward. The statistical damage theory was introduced and the statistical damage constitutive model was built,considering that the damage threshold has the influence on the measurement method of rock damage. The determination methods of the model parameters were given according to the features of the rock triaxial test curve. Based on the relationship respectively between the confining pressure with the peak stress and peak strain,the statistical damage constitutive model was constructed,which can reflect the deep earth rocks deformation under different confining pressures. The trial curves were compared with the prediction curves with the proposed model in this paper. The results show that the proposed constitutive model can reflect the deformation process of deep earth rocks. The model may also reflect the properties of the changes of strength with the confining pressure. The feasibility and rationality of the proposed model and method were indicated.