水对花岗岩巷道岩爆红外辐射特征的影响

Influence of water on infrared radiation characteristic of granite roadway rock burst

为研究水对岩爆发生的影响,采用自然与饱水花岗岩进行岩爆模拟实验,以美国Therma CAM SC3000红外热像仪为观测手段,研究了水对花岗岩巷道岩爆红外辐射特征的影响.结果表明:饱和花岗岩AIRT初始阶段温度上升速度快;岩爆发生前饱和岩样最高、最低温度均有微小突变,饱和岩样的岩爆前兆特征更易捕捉.岩爆瞬间,自然岩样孔洞左右两侧AIRT突然升高,岩样表面最低温度曲线呈线性上升,而饱和岩样AIRT和最低温度曲线均下降;饱和花岗岩AIRT平均值比自然花岗岩高,并且单位载荷下AIRT增量更大;趋近岩爆发生,花岗岩红外辐射温度表现出临界慢化特征,系统内在变化速率降低,与前一时刻状态越来越相似,其自相关系数转向增大的趋势,这可以作为岩爆发生的前兆特征.

To study the influence of water on rock burst, an experiment was carried out to simulate rock burst with natural and saturated granites. The infrared thermal imager Therma CAM SC3000 produced by American was selected as observation method. This paper studied the infrared radiation temperature characteristics of granites under different moisture conditions. It is found that AIRT of saturated granite rise faster than what with natural granite in initial stage. The maximum and minimum temperature of saturated sample show tiny mutation before rock burst, so the precursory characteristic of rock burst with saturated sample is easier to catch. The AIRT with natural granite left and right sides of the hole suddenly increase, and the lowest temperature with surface of the sample rise linearly when rock burst occurs. While the AIRT and lowest temperature with saturated granite decline when rock burst occurs. The AIRT and AIRT increment under unit load of saturated granites is higher than that of natural granites. Infrared radiation temperature shows critical slowing down phenomenon approaching to rock burst. Internal changing rate of system reduces, and the status is more and more similar to what with previous moment, namely autocorrelation coefficients turn to increase, which can be used as precursory characteristic of rock burst.