The rocks around wellbores in energy-storage areas are affected by high temperatures and thermal stresses during the extraction of geothermal resources. In this study, the mechanical properties of torus granite samples with different aperture ratios and sizes are experimentally investigated at high temperatures. Further, Acoustic Emission (AE) and Digital Image Correlation (DIC) technology are used to monitor the deformation and failure process of torus granites. The research results show that the radial peak load decreases exponentially with increases in the aperture ratio, temperature, and thermal damage. 400 °C is the critical threshold for the strength instability of the torus granite. According to the failure characteristics. When the aperture ratio λ < 0.3, linear tensile cracks appear in the granite, and the “double fan” failure mode is finally formed. When the heating temperature reaches 400 °C, torus granite successively formed linear cracks and horizontal tensile cracks, and finally a ‘four fan’ failure mode. When the heating temperature reaches 600 °C, the horizontal tensile cracks produced when the torus granite fails evolve from asymmetric to symmetrical. Based on the deformation and failure results of the torus granite under compression, the dynamic failure criterion of the inner and outer pore walls of the torus granite under radial compression is derived. Finally, the theoretical analysis and experimental results are compared, the scale and temperature effects of the failure mode of the torus granite are deeply analysed. This study results can provide theoretical reference for surrounding rock support and shaft diameter ratio design.

在地热资源开采过程中，储能区井眼周围的岩石会受到高温和热应力的影响。在这项研究中，实验研究了具有不同孔径比和尺寸的环面花岗岩样品在高温下的力学性能。此外，声发射（AE）和数字图像相关（DIC）技术用于监测花岗岩环面的变形和破坏过程。研究结果表明，随着孔径比、温度和热损伤的增加，径向峰值载荷呈指数下降。400 °C 是花岗岩强度不稳定性的临界阈值。根据故障特点。当孔径比λ<0.3时，花岗岩出现线状拉伸裂纹，最终形成“双风机”故障模式。当加热温度达到400℃时，环面花岗岩依次形成线状裂纹和横向拉伸裂纹，最终形成“四扇”破坏模式。当加热温度达到600℃时，环面花岗岩破坏时产生的水平拉伸裂纹由不对称向对称演化。根据花岗岩环面受压变形破坏结果，推导了环面花岗岩内外孔壁径向受压的动态破坏准则。最后，将理论分析与实验结果进行对比，深入分析了花岗岩花岗岩破坏模式的规模效应和温度效应。研究结果可为围岩支护及轴径比设计提供理论参考。