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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。
In order to investigate the characteristics of infiltration and acoustic emission in the process of deformation and failure of fine sandstone, MTS 815 rock mechanics test system and PAC PCI-2 acoustic emission test station were used to test the permeability and AE characteristics of fine sandstone under triaxial compression The variation law of permeability, permeability-strain relationship, acoustic emission characteristics and its relationship with permeability were analyzed. The results show that the permeability changes with the stress-strain curve in the process of deformation and failure of fine sandstone. The permeability changes under different confining pressures are similar. The permeability decreases with the increase of confining pressure. The transverse strain ε3 and infiltration The change rule of the rate K with the axial strain ε1 is basically the same. The point of abrupt increase of the transverse deformation corresponds to the point of the permeability change, which can better reflect the change of permeability. The characteristics of acoustic emission reflect the development of cracks during the deformation and failure of fine sandstone , Evolutionary process, acoustic emission and stress-strain and permeability all have good correlations; the energy parameters of AE parameters increase with the increase of confining pressure. The analysis based on acoustic emission characteristics can better reveal the occurrence and development of cracks in the process of rock deformation and failure, which is helpful to understand the mechanism of rock permeability change.