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岩石渐进破坏伴随着裂纹的开展发育,岩石的渗透性演化与裂纹的开展规律有着密切的联系。运用三轴渗流伺服装置对凝灰岩进行了不同围压和渗压下的渗流-应力耦合试验,分析了岩石在渐裂过程中不同裂纹开展阶段渗透率的演化规律。结果表明:在裂纹的稳定扩展阶段,渗透率的变化不明显,起裂强度对应的渗透率可用于确定最小渗透率;进入裂纹非稳定扩展阶段后,渗透率出现明显增大,增大过程可以分为两个阶段,裂纹环向应变能较好地反映渗透率增大的两个阶段,其拐点可用于确定起始渗透率的位置;在峰后软化阶段,渗透率出现下降并进入残余稳定阶段,裂纹环向应变率可以反映渗透率的下降阶段,并可用于确定峰值渗透率的位置。
The gradual destruction of rocks accompanied by the development of cracks, and the evolution of rock permeability and the crack initiation are closely related. The seepage stress-stress coupling test of tuff under different confining pressures and seepage pressures is carried out by using a three-axis seepage servo system. The evolution of permeability during different crack initiation stages is analyzed. The results show that the permeability does not change obviously during the stable propagation of the crack, and the permeability corresponding to the rupture strength can be used to determine the minimum permeability. After entering the crack non-stable expansion stage, the permeability increases obviously, and the increasing process can There are two stages, the crack circumferential strain energy can better reflect the two stages of permeability increase, the inflection point can be used to determine the initial permeability of the position; in the post-peak softening stage, the permeability decreases and enters the residual stability Stage, the crack circumferential strain rate can reflect the decline of permeability and can be used to determine the location of peak permeability.