To truly reflect changes in apparent resistivity before and after hydraulic fracturing (HF) of coal and rock masses in underground spaces, the fracturing effect should be investigated and evaluated. In this paper, experiments were conducted on true triaxial HF in rocks to investigate the apparent resistivity response law. The results show that the change in apparent resistivity was regular and uneven in the process of HF. The combined action of hydraulic cracks and fracturing water were the decisive factor in the apparent resistivity change. According to the time-sequence characteristics of apparent resistivity, the crack initiation sequence and spatial location can be reflected intuitively. The abrupt change and abnormal fluctuation in apparent resistivity near the cracks are important for crack initiation and propagation. Due to the difference in hydraulic crack shape and scope, the influence of cracks and fracturing water differs on different directions of rock. Therefore, the variation trend of apparent resistivity was different along various survey lines. After three-dimensional stress unloading, the water content in the cracks was affected by the crack opening, water storage space and drainage capacity, resulting in an obvious regional variation in apparent resistivity. The changes in apparent resistivity characteristics of true triaxial HF contain rich information about the fracture process, which is significant for guiding on-site HF and effect evaluation.

为了真实反映地下空间煤岩体水力压裂（HF）前后视电阻率的变化，需要对压裂效果进行调查和评价。在本文中，对岩石中的真三轴高频进行了实验，以研究视电阻率响应规律。结果表明，在HF作用过程中，视电阻率的变化规律且不均匀。水力裂缝和压裂水的共同作用是视电阻率变化的决定性因素。根据视电阻率的时间序列特征，可以直观地反映裂纹萌生序列和空间位置。裂纹附近视电阻率的突变和异常波动对裂纹的萌生和扩展具有重要意义。由于水力裂缝形状和范围的不同，裂缝和压裂水对岩石不同方向的影响也不同。因此，不同测线的视电阻率变化趋势不同。三维应力卸载后，裂缝中的含水量受裂缝开口、储水空间和排水能力的影响，导致视电阻率出现明显的区域变化。真三轴高频视电阻率特征的变化包含了丰富的断裂过程信息，对指导现场高频和效果评价具有重要意义。不同测线视电阻率变化趋势不同。三维应力卸载后，裂缝中的含水量受裂缝开口、储水空间和排水能力的影响，导致视电阻率出现明显的区域变化。真三轴高频视电阻率特征的变化包含了丰富的断裂过程信息，对指导现场高频和效果评价具有重要意义。不同测线视电阻率变化趋势不同。三维应力卸载后，裂缝中的含水量受裂缝开口、储水空间和排水能力的影响，导致视电阻率出现明显的区域变化。真三轴高频视电阻率特征的变化包含了丰富的断裂过程信息，对指导现场高频和效果评价具有重要意义。