天空冷背景下受力岩石微波辐射特征实验研究

Experimental Study on the Microwave Radiation of Stressed Rock Under Cold Sky Background

分析了环境因素对微波辐射观测的影响机理.以此为基础,在天空冷背景条件下,利用岩石试验机、微波辐射计、声发射、温度测试仪等,开展了岩石弹性变形阶段循环加载微波辐射变化特征的室外观测实验.结果表明,在天空冷背景下能可靠获取岩石受力变形过程中的微波辐射能量变化信息.花岗岩弹性变形阶段的微波辐射亮温变化与应力间呈同步性很强的正相关关系,相关系数达0.94;岩石表面的温度变化与应力间亦呈正相关,但其变化滞后于应力变化,且单位应力的微波亮温升幅远大于表面温度升幅.实验证实了利用微波辐射观测手段可有效探测岩石受力引起的岩石内部应力状态的变化.

How environmental factors affect microwave radiation observation was analyzed.Based on the analysis,outdoor experiments were carried out with rock test machine,microwave radiometer,acoustic emission instrument,temperature tester and other equipment to observe microwave radiation characteristics of elastically deformed rock with cyclic loading under cold sky background.Results indicate that the microwave radiation energy changes generated from deformed rock can be detected reliably under cold sky background.In the elastically deformed granite,the microwave radiation energy changes and stress present the positive correlation,with the correlation coefficient of 0.94.The temperature change of the rock surface is positively correlated with the stress too,but the temperature change lags behind the stress change,and the microwave brightness temperature increment is much larger than the surface temperature rise per unit stress.It is verified that the changes in the internal stress state of rock can be detected by microwave observation.