基于脆性岩石破裂过程中特征点的能量密度研究

Energy Density Based on Characteristic Point During Rock Mass Failure Process

岩石的变形破坏过程分为5个阶段:压密阶段、弹性阶段、稳定破裂阶段、非稳定破裂阶段、峰后阶段.针对各阶段中的力学联系鲜有研究,本文结合重整化群理论与方法,引入岩石脆性度m值分析岩石变形破坏过程,构建岩石应力-应变曲线变形膨胀点与峰值强度点的力学联系,并以此建立岩石变形膨胀点与峰值强度点处能量密度联系,研究发现岩石变形膨胀点与峰值强度点处能量密度之比(E f/E cd)是一个只依赖岩石脆性度m值的常数,并以此建立脆性岩石破坏模型.结合相关脆性岩石单轴压缩试验,结果表明:实测数据(E f/E cd)与理论值趋势较为一致,且符合较好.说明本文建立的能量密度模型能够很好地诠释脆性完整岩石的变形破坏过程.

Rock mass failure process is divided into several distinct deformation stages including compaction stage, elastic stage, stable failure stage, accelerated failure stage and post-peak stage. Although each individual stage is well studied, the quantified relationship between the stages has not been established yet. In this study, we first studied the mechanical relationship between the volume dilatant point and the peak stress point in the stress-strain curve of rock using renormalization group theory. Based on the relationship above, we builded up the energy relationship between the volume dilatant point and the peak stress point by introducing the shape parameter m. It is inferred that the energy ratio of the volume dilatant point and the peak stress point is solely the function of the shape parameter m. Several uniaxial compression tests are conducted to investigate the failure process of the granite specimens. It is found that the experimental results shares very similar trend to that from the theoretical model, our study demonstrates that the energy analysis protocol established by introducing the shape parameter m can be applied to the study of the failure process of brittle intact rock.