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采用FLAC模拟了初始内聚力及内摩擦角对具有随机材料缺陷单轴平面应变压缩岩样破坏过程及声发射的影响;采用编写的若干FISH函数规定随机缺陷及统计发生破坏的单元数目.密实的岩石服从莫尔-库仑剪破坏与拉破坏复合的破坏准则,破坏之后呈现应变软化-理想塑性行为;缺陷在破坏之后经历理想塑性行为.随着密实岩石强度参数的提高,从应力峰值到残余应力的应力降、轴向应变增量提高,贯通试样的剪切带出现滞后,试样内部最终发生破坏的单元数降低.对于密实岩石强度参数高的试样,缺陷全部发生破坏之后,密实岩石没有立即发生破坏;应力峰值被达到之后,破坏的单元数增长不大.在加载过程中,声发射数有显著增加的三个区段.区段1、2及区段3的绝大部分位于峰前.在区段3的峰前阶段,声发射数的增加源于缺陷的长大、聚结、传播和竞争.强度参数越高,区段3越长,区段3的峰值越低.这表明当密实岩石的强度参数较高时,密实岩石单元破坏相继发生,破坏过程持续得较长.
FLAC was used to simulate the influence of initial cohesion and internal friction angle on the failure process and acoustic emission of a uniaxial plane strain compression rock sample with random material defects. Some FISH functions were written to specify the random defects and the number of destroyed units. Subject to the failure criterion of Mohr-Coulomb shear failure and pull failure, the strain softens-ideal plastic behavior after failure, and the defect experiences ideal plastic behavior after failure.With the increase of the density parameter of dense rock, from the stress peak to the residual stress Stress drop and axial strain increment increase, the shear band of the through specimen lags behind, and the number of units that will eventually be damaged in the specimen decreases.For the specimens with high strength of rock, all the defects are destroyed, and the dense rock has no Damage occurred immediately after the peak stress was reached, the number of damaged cells increased little.In the loading process, there is a significant increase in the number of acoustic emission of the three sections of the first and second section 3 and section 3 is located in the peak The increase in acoustic emission from the pre-peak phase of section 3 results from the growth, coalescence, propagation and competition of defects.The higher the intensity parameter, the greater the intensity of section 3 Long, lower section 3 of the peak. This means that when high strength parameters dense rock, rock compaction unit have occurred damage, destruction process lasted long.