单轴加载岩石损伤及声发射特性非均质效应的数值试验

摘要

To investigate the influence of rock heterogeneity on mechanical properties,RFPA2D used for analysis of rock failure process was applied to study the damage evolution mode and acoustic emission characteristic of rocks with various kinds of heterogeneity.The results show that rock heterogeneity has remarkable influence on its mechanical properties.As the rock heterogeneity increases,the damage evolution mode of rock changes from ductile failure into brittle failure,and the dispersivity of macroscopic unstable failure decreases.At the same time,peak strength of rocks increases continuously,and finally reaches to a stable value.It is also found that when the rock heterogeneity is low,acoustic emission of rocks under uniaxial loading reflects a property of low intensity and high frequency.Acoustic emission strength and mutagenicity of rocks increase with higher rock heterogeneity.%为研究岩石非均质性对其力学特性的影响,运用岩石真实破裂过程分析软件RFPA2D,并采用岩石单轴常位移加载方式,分析不同均质度条件下岩石损伤演化模式和声发射特性.研究结果表明:均质度对岩石力学特性影响显著,随着岩石均质度的增高,岩石单轴加载损伤演化模式由延性向脆性过渡,宏观破裂弥散性降低,岩石峰值强度不断增大,当均质度大于30时,岩石峰值强度基本趋于稳定；岩石均质度较低时,单轴加载条件下岩石声发射体现出强度低、事件频率高的声发射特性,均质度增高时,岩石声发射强度也进一步提高,并且突变性增强.