EXPERIMENTAL STUDY ON ACOUSTIC AND THERMAL INFRARED CHARACTERISTICS OF BUMP-PRONE COAL
冲击倾向性煤体破坏过程声热效应的试验研究

The acoustic and thermal infrared(TIR) characteristics of bump-prone coal are briefly described with different loading tests.The experimental system is designed,which is composed of the TIR observation system,the stress and strain measurement system and the acoustic emission monitoring system.It can be used to achieve different kinds of forewarning messages before the failure of rock or coal samples.The uniaxial compression loading test and the cyclic loading test are carried out to observe the features of TIR,acoustic emission and strain forewarning messages.Moreover,the response speed and the sensitivity of different monitoring systems to the cracking events in the samples are also studied under different loading conditions;and the physico-mechanical characteristics of bump-prone coal are obtained.The statistical investigation on the forewarning stress points is conducted based on the TIR images,infrared radiation temperature,acoustic emission and strain data.The analytical results show that the stress of ninety percent of strength should be regarded as the stress-caution-point for the failure of bump prone coal,which is much higher than the stress of seventy percent of strength as the stress-caution-point for the general coal samples.So it is more difficult to forecast the failure of the bump-pone coal under different loading conditions.