采用真三轴试验系统对含圆形贯穿孔洞的立方体花岗岩试样进行真三轴压缩试验,研究饱和含水量(SWC)对圆形隧道围岩破坏过程和特征的影响.SWC条件下板裂化破坏可分为4个阶段:平静阶段、屈曲变形阶段、岩片逐渐屈曲和剥落阶段及形成对称的V型槽阶段.当水平轴向应力和垂直应力保持不变时,板裂化破坏的严重程度随着侧向应力的增加而降低.在自然含水量条件下,圆形孔洞边墙发生具有动态破坏特征的强岩爆;在SWC条件下,破坏的严重程度降低,圆形孔洞围岩发生板裂化破坏,表现出渐进的静态破坏特征.因此,在深部地下工程中,水可以降低围岩破坏的严重程度,对岩爆防治具有一定的指导意义.
True-triaxial compression tests were carried out on cubic granite samples with a circular through hole using a true-triaxial testing system to investigate the influence of saturated water content (SWC) on the failure process and characteristics of a circular tunnel of surrounding rocks. The spalling failure under SWC can be divided into four periods: calm period, buckling deformation period, period of rock fragment gradual buckling and exfoliation, and period of formation of symmetrical V-shaped notches. When the horizontal axial and vertical stresses were constant, the spalling failure severity was reduced with the increase in lateral stress. Under natural water content, a strong rockburst with dynamic failure characteristics occurred on the circular hole sidewall. Under SWC, the failure severity was reduced and the circular hole sidewall experienced spalling failure, exhibiting progressive static failure characteristics. Therefore, water can reduce the failure severity of surrounding rocks in deep underground engineering, which has a certain guiding significance for the prevention and control of rockbursts.