Abstract
The destabilization and damage process of the coal-rock body is accompanied by the release of acoustic and thermal signals. In order to investigate the destabilization and damage precursor signal characteristics of coal-rock combination bodies with different ratios, and to analyze the reliability and applicability of the warning signals, this paper carries out the uniaxial compression tests of 7 different ratios of coal-rock combined body specimens by using the rock mechanics loading test system and the synchronous monitoring platform of IR and AE and analyzes the destructive precursor feature laws of specimens in terms of the mechanical, acoustic-emission, infrared thermographic, and temperature characteristics, respectively. The results show that: the strength characteristics of the specimens satisfy the linear relationship with the coal-rock ratio, the smaller the coal-rock ratio is, the greater the uniaxial compressive strength of the specimens and the more obvious the tensile damage is. The AE counts of the coal-rock combined body damage precursors are positively correlated with the coal-rock ratio, and the AE peak count is negatively correlated with the coal-rock ratio, and the smaller the coal-rock ratio is, the closer the slope of AE cumulative counts curves is to 1 at the stage of the peak damage. In the elastic and yielding phases, the MIRT curve fluctuates and rises, and before the peak damage, the MIRT curve shows a "V" shape, and the smaller the coal-rock ratio is, the more obvious the "V" shape is. When the coal-rock ratio is 1:3 or less, the monitoring effect of IR is better than that of AE, and AE monitoring is more suitable for specimens with a coal-rock ratio greater than 1:3. When the coal-rock ratio is 3:1, IR monitoring is not as effective as AE monitoring. Therefore, the synergistic monitoring of AE and IR can make the early warning signal of coal-rock combination bodies damage precursor more reliable and accurate.