【目的】探索相同高温状态下花岗岩在不同冷却模式(20℃水中热冲击冷却和20℃空气中自然冷却)下不同的力学特性。【方法】采用实验室自研热冲击破裂实验平台,对两种冷却模式下不同温度状态(25~600℃)花岗岩进行单轴抗压、巴西劈裂、变角剪切试验,测试其单轴抗压强度、抗拉强度、内聚力、内摩擦角宏观力学参数,研究不同冷却模式下高温花岗岩力学特性的演变规律。【结果】结果表明:1)冷却模式对单轴抗压强度、抗拉强度、内聚力的影响较大,对内摩擦角几乎无影响;2)相同高温状态下花岗岩力学强度在20℃水中热冲击冷却劣化更严重,且300℃为两种冷却模式出现差异的阈值温度;3)当加热温度为600℃时,热冲击冷却后花岗岩的单轴抗压强度、抗拉强度、抗剪强度(内聚力)与自然冷却模式下相比分别降低了27.6%、51.7%、33%,这说明冷却模式对花岗岩力学强度影响从大到小依次为抗拉强度、抗剪强度、抗压强度。【结论】研究结果可为相同工况下高温岩石力学工程岩体稳定性分析提供了一定的参考。

【Purposes】The mechanical properties of granite in the same high temperature state un-der different cooling modes (thermal shock cooling in water at 20 ℃ and natural cooling in air at 20 ℃) are different.  【Methods】By using the laboratory self-developed thermal shock fracture experimental platform, uniaxial compression, Brazilian splitting, and variable-angle shearing (45°, 55°, 65°) were carried out on granite in different temperature states (25-600 ℃) under two cooling modes.  To test its uniaxial compressive strength, stress-strain curve, peak strain, tensile strength, cohesion c, inter-nal friction angle φ and other macro-mechanical parameters.  Besides, the evolution of the mechanical properties of high-temperature granite under different cooling modes was studied.  【Findings】The re-search results show that: 1) the cooling mode has a great influence on the uniaxial compressive strength, tensile strength, and cohesion c, but has little effect on the internal friction angle; 2) The mechanical strength of granite at the same high temperature deteriorates more seriously with thermal shock cooling in water at 20 ℃, and 300 ℃ is the threshold temperature for the difference between the two cooling modes; 3) From 25 ℃ to 600 ℃, compared with natural cooling, thermal shock cooling caused compressive strength, tensile strength, and shear strength (cohesive force) deteriorations of granite which are 51. 7%, 33%, and 27. 6%, respectively, showing that the cooling mode affects the mechanical strength of granite in descending order: tensile strength, shear strength, and compressive strength.  【Conclusions】The research results can provide test reference for related projects.