基于声发射定位技术岩石破坏逾渗特征研究

通过单轴加载条件下岩石破坏声发射实验,分析了岩石在受载过程中破坏单元的演化规律,对岩石破坏过程中的逾渗特征进行了探讨.分析结果表明:声发射定位事件反映了岩石内部微裂纹产生、扩展的演化过程,基于声发射定位事件对岩石内部破坏单元进行划分,能够反映破坏单元从无序分布向有序集中的自组织演化过程.岩石失稳破坏前,破坏集团数目与破坏集团规模——数目的负幂指数均出现增长变缓的趋势,反映了破坏单元的大面积贯通过程,岩石由稳定的破裂阶段转变为非稳定的破裂阶段.在破坏单元达到一定概率时应变开始突发式增长.基于声发射定位事件对破坏单元进行划分,从物理实验的角度研究岩石逾渗问题,具有实际应用价值.

Study on Characteristics of Percolation in Rock Failure Process via Acoustic Emission Locating Technique

Experiments for rock failure process under uniaxial compression were carried out via the acoustic emission (AE) locating techniques to study the evolution process of failure elements and percolation characteristics during rocks failure. The results showed that the 3-D location of AE events directly reflects the processes of initiation, propagation and evolution of micro-cracks. Dividing the failure elements in rocks by locating AE events, the orderly and centralized self-organizing evolution of failure elements was shown from random distribution. Before the rock failure due to instability, the number of failure clusters and the relationship of negative power exponent between the scale and the number of failure clusters tend to increase slowly, which suggests that the failure elements begin to swarm in a large area, thus causing the rock in stable fracture phase to turn into unstable fracture phase. When the probability of failure comes up to a certain value, the strain of rock begins increasing abruptly. The experimental study on rock percolation via dividing failure elements in accordance to AE locating events is a new way for studying rock failure mechanics.