ACOUSTIC EMISSION AND INFRARED CHARACTERISTICS OF COAL BURST PROCESS

摘要

Strain coalburst tests of coal samples were carried out by the experimental system of rockburst to study the coal disaster mechanism at a high stress state. The acoustic emission (AE) signals and the infrared thermography for the coal samples were detected and obtained during the tests. We mainly investigated the coalburst mechanism of the coal samples by AE technique and infrared thermography from unloading to failure. The basic parameters such as the energy rate and AE events were used to transform the data between time and frequency. AE events significantly increased during unloading. There were obvious high-temperature zones before coal burst. It is concluded from the characteristics of AE and infrared thermography of coalburst process that there are the stress concentration phenomena within the coal samples and the local high-temperature zone appeared from the infrared thermography. It is indicated by the intensive AE activity that as the partial release of stress before coalburst, macro-cracks were formed and extended. Thus a large amount of energy was released, inducing coalburst.