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利用自主研发的真三轴岩爆试验系统,以200℃~700℃不同高温冷却后和常温25℃下的红色粗晶花岗岩作为岩样,进行岩爆弹射破坏过程模拟物理的试验。在借助高速摄像系统和声发射系统监测岩爆过程的基础上,分析了不同高温作用后岩样的岩爆弹射过程、破坏形态特征、峰值强度、声发射特性、碎块特征以及弹射动能的变化规律。研究结果表明:随着温度的升高,岩样从出现小颗粒弹射到整体弹射破坏的时间间隔逐渐减少;300℃为该类花岗岩高温后单面临空真三轴强度的阀值温度,小于等于300℃时,岩样的峰值强度变化不大,岩样脆性随温度的升高而增大,大于300℃时,岩样的峰值强度呈明显下降趋势,岩样的脆性随温度升高而降低;在岩样压密阶段,声发射撞击数随温度升高而增大,大于300℃时,岩爆发生前夕声发射撞击数显著下降的“平静期”持续时间随温度升高呈增大趋势;25℃~300℃温度范围内,岩爆弹射动能随温度升高明显增大,300℃~700℃高温后,岩爆弹射动能随温度升高显著减小。
Using the self-developed true triaxial rock burst test system, the simulation test of the rockburst catastrophic failure process is carried out with red coarse-grained granite cooled at different temperature from 200 ℃ to 700 ℃ and 25 ℃ at room temperature. Based on the monitoring of rockburst with high-speed camera system and acoustic emission system, the rockburst ejection process, the damage morphological characteristics, the peak intensity, the acoustic emission characteristics, the characteristics of fragments and the ejection kinetic energy of the rock samples after high temperature were analyzed law. The results show that with increasing temperature, the time interval from small particle ejection to total ejection failure of rock samples decreases gradually. The threshold temperature of true triaxial strength of one kind of granite after being heated at 300 ℃ is less than or equal to At 300 ℃, the peak intensity of rock samples did not change much, and the brittleness of rock samples increased with the increase of temperature. When the temperature was higher than 300 ℃, the peak intensity of rock samples obviously decreased. The brittleness of rock samples decreased with the increase of temperature ; In the stage of rock compaction, the number of acoustic emission impacts increases with temperature. When the temperature is above 300 ℃, the number of acoustic emission impacts significantly decreases on the eve of rockburst, and the duration of “quiet period” tends to increase with increasing temperature In the temperature range from 25 ℃ to 300 ℃, the ejection kinetic energy of rock burst increases with increasing temperature. After 300 ℃ ~ 700 ℃, the ejection kinetic energy of rock burst decreases with increasing temperature.