【摘要】 为探讨细砂岩变形破坏过程中的渗透特性及声发射特征,采用MTS 815岩石力学试验系统及PAC PCI–2声发射测试工作站,对细砂岩进行三轴压缩条件下的渗透性和声发射特征试验,分析全过程中渗透率的变化规律、渗透率–应变关系、声发射特征及其与渗透性之间的关系。研究表明:细砂岩变形破坏过程中渗透率随应力–应变曲线呈阶段性变化,不同围压下渗透率的变化规律相似,随着围压升高,渗透率量值降低;横向应变ε3与渗透率K随轴向应变ε1的变化规律基本一致,横向变形增加的突变点与渗透率的突变点相对应,更能反映渗透性的变化;声发射特征反映了细砂岩变形破坏过程中裂纹的发展、演化过程,声发射和应力–应变、渗透率均具有很好的相关性;声发射特征参数能量率随围压升高而增大。基于声发射特征的分析能更好地揭示岩石变形破坏过程中裂纹的产生和发展状况,有助于深入认识岩石渗透性的变化机制。更多还原

【Abstract】 In order to discuss the permeability and acoustic emission characteristics of fine sandstone during the deformation and failure process,a series of tests for characteristics of permeability and acoustic emission were performed under triaxial conditions by using MTS 815 rock mechanical test system and PAC PIC–2 acoustic emission test station. The variation of permeability,the relationship between permeability and strain and the acoustic emission characteristics were studied. The results show that the permeability during the process of deformation and failure changes in accord with the stress-strain curves,and the rules under different confining pressures are similar. The permeability decreases with confining pressure increasing. The changes of permeability and lateral strain ε3 with axial strain ε1 have a good corresponding relationship. The point where ε3 increases sharply is corresponding to where permeability increases,so ε3 reflects the variation of permeability better. The acoustic emission characteristics in the whole process reflect the development of the cracks,and the acoustic emission correlates well with the stress-strain and permeability. The energy rate,one of the parameters of acoustic emission,increases with confining pressure increasing. The characteristics of acoustic emission can reveal the emergence and development of fractures in rocks,which can develop a deeper understanding of the variation of permeability during the deformation and failure process.更多还原