| A series of lithology rockburst tests have been conducted by the true triaxial rockburst simulating test system with the new experimental approaches, including granite, sandstone, limestone and coal. The phenomenon of rockburst is reproduced in laboratory. The energy chatacteristics of rockburst were analyzed on two aspects, i.e, acoustic emission (AE) release energy and the rockburst fragments dissipate energy. The release energy characteristics of acoustic emission were investigated in details based on AE release energy ratio and AE cumulative energy. The predominant frequency of AE was identified according to the frequency spectrum results. According to the time-frequency distribution and the post-failure sample scanning electron microscope images, we observe that in most cases, the transgranulation-shear cracks are of high energy releasing and the intergranular-tensile ones are of low energy releasing. The distribution of rockburst fragments was researched and their dissipation energy characteristics were also analyzed preliminary.
|
PDF Full Text Request