岩石破坏失稳的声发射响应与损伤定量表征研究

Study on acoustic emission response and damage quantitative characterization of rock destruction and instability

为了探索在外载荷作用下岩石的损伤演化规律及声发射响应特征,实现损伤程度的定量表征,以标准岩石试件为研究对象,采用RMT-301岩石力学试验系统和DS5-8B全信息声发射仪,开展单轴加载条件下岩石破坏全过程的声发射(AE)试验研究,根据声发射参数、声发射源三维定位、声发射能量密度和岩石力学分析表征其破坏形态,再现岩石裂隙孕育、发展和贯通过程,揭示岩石破坏规律、能量密度分布特征、裂隙空间演化和AE时序参数;以时间为中间变量,建立声发射累计振铃计数和应力、应变及损伤变量的耦合关系;基于岩石损伤演化方程,进一步建立声发射累积能量和应力、应变的定量模型。研究结果对揭示岩石破坏机制、区分岩体强度具有指导意义,为矿山煤岩动力灾害的预测预警提供一定理论支撑。

In order to explore the damage evolution laws and acoustic emission(AE)response characteristics of rock under external loading,and realize the quantitative characterization of damage degree,taking the standard rock specimen as the research object,the AE test research on the whole process of rock destruction under the uniaxial loading conditions were carried out by using the RMT-301 rock mechanics test system and DS5-8b acoustic emission instrument.The destruction shapes were characterized according to the AE parameters,three-dimensional localization of AE source,AE energy density and rock mechanics analysis,then the inoculation,development and cut-through processes of rock fracture were represented,and the rock destruction laws,distribution characteristics of energy density,spatial evolution of fracture and AE timing sequence parameters were revealed.Taking time as the intermediate variable,the coupling relationship between the cumulative AE ringing count and the stress,strain and damage variables was established.Based on the rock damage evolution equation,the quantitative model of cumulative AE energy,stress and strain was established.The research results have guiding significance to reveal the destruction mechanism of rock and distinguish the strength of rock mass,and provide theoretical support for the prediction and early-warning of coal and rock dynamic disasters in the mines.