Microseismic effect of coal materials rockburst failure induced by hard roof
坚硬顶板诱发煤体冲击破坏的微震效应

By TDS-6 microseism (MS) test system, the MS effect of the compound coal-rock samples from Xinzhouyao Coal Mine was studied in the process of deformation, fracture and rockburst failure, especially the evolvement of MS frequency-spectrum before and after rockburst failure was revealed. Using SOS MS monitoring system, the MS activity patterns of working face 8929 of Xinzhouyao Coal Mine were measured. The achieved results are as follows. (1) The rockburst precursory signal shows low-frequency character, the shorter the interval time between precursory and mainshock signal is, the lower the main frequency is. The spectrum of mainshock signal is wider, but the low-frequency component (0～50 Hz) will increase obviously. The aftershock signal shows high-frequency feature. (2)The correlation between the events, the total energy and the main frequency of MS signals is negative. Especially when the pressure and rockbursts were induced by roof fracture, the main frequency of MS signals is lowest. (3) The main frequency of rockburst precursory signals is about 0～50 Hz by measurement in field, and amplitude is lower. The spectrum of rockburst signals is wider, and the low-frequency component (0～20 Hz) will obviously increase, simultaneously the amplitude reaches to maximum. After rockburst, MS signals show the high-frequency and low-amplitude feature, and main frequency is about 0～200 Hz.