【摘要】 为探究高地温条件下深部花岗岩的损伤演化规律及岩爆倾向性，采用MTS 815 Flex GT岩石力学试验系统对常温、55℃和75℃温度条件下的深部花岗岩开展三轴压缩试验，并结合声发射（AE）实时监测与扫描电子显微镜（SEM）观测技术，对不同温度下花岗岩的力学行为、声发射特征和破坏模式进行系统研究，同时通过脆性指数与冲击能量指数定量评价其岩爆倾向性。结果表明：温度升高显著削弱了花岗岩的脆性与岩爆潜势，具体表现为脆性指数由常温下的0.62降低至55℃时的0.30，并在温度升高至75℃时进一步降低至0.25，同时破坏模式由以沿晶劈裂为主的集中脆性破坏逐渐转变为多裂隙弥散型破坏。常温下，花岗岩断口平整，声发射表现为峰值前突发式高能信号，呈强岩爆倾向性；当温度为55℃时，试样呈现破碎断裂特征，声发射出现分阶段能量跃升，仍保持强岩爆倾向性；当温度为75℃时，断口微裂纹密集且杂乱，声发射转化为连续释放，冲击能量指数为1.94，岩爆倾向性减弱。研究揭示，高温通过增强内部裂纹萌生与发展、促进能量渐进耗散，削弱了岩石弹性能积聚和突发释放能力，推动花岗岩从高脆性向低脆性演化，进而弱化岩爆风险，可为深部高温地质环境下岩爆预测与防控提供理论支撑。更多还原

【Abstract】 In order to examine the progression of damage and the propensity for rockburst in deep granite subjected to high geothermal temperatures, triaxial compression tests were performed on granite specimens at three distinct temperatures: ambient(25 ℃), 55 ℃, and 75 ℃, utilizing the MTS 815 Flex GT rock mechanics testing system. The study employed acoustic emission(AE) monitoring and scanning electron microscopy(SEM) to conduct a comprehensive analysis of the mechanical behavior, AE characteristics, and failure patterns of granite under varying thermal conditions. Additionally, the brittleness index and impact energy index were utilized to quantitatively assess the rockburst tendency. The findings demonstrate that temperature significantly influences the acoustic emission(AE) characteristics, failure modes, and rockburst propensity of granite. Under ambient temperature conditions, granite predominantly undergoes intergranular brittle failure, characterized by smooth fracture surfaces, and the AE signals are marked by abrupt high-energy bursts preceding the peak stress. The brittleness index at this temperature is 0.62, indicating a pronounced rockburst tendency. At 55 ℃, the specimens exhibit fragmented failure features, and the AE signals reveal staged energy surges. Although the brittleness index decreases to 0.30, the rockburst tendency remains pronounced. At 75 ℃, the fracture surfaces display densely distributed and disordered microcracks, with AE signals transitioning to continuous emissions, and the brittleness index further decreases to 0.25. The impact energy index decreases to 1.94, indicating a diminished tendency for rockburst occurrence. These results demonstrate that increased temperature enhances the initiation and propagation of internal microcracks, facilitating progressive energy dissipation. Consequently, this process reduces the accumulation and abrupt release of elastic energy, thereby transitioning granite from high to low brittleness and ultimately mitigating the risk of rockburst. This study offers theoretical support for predicting and mitigating rockburst hazards in deep, high-temperature geological settings.更多还原