Abstract:Using seismic monitoring system,abundant microseismic signals are collected during the period of three pillar type rockburst occurs in No.11 mine of Pingmei group. The time sequence of microseismic signal in this period is obtained and the frequency spectrum and spatial distribution are analyzed by fast Fourier transformation(FFT) algorithm and fractal theory. The achieved results are as follows. (1) An obviously active phase occurred before the pillar-type rockburst happens. It is indicates that the surrounding rock mass system is in an energy releasing process and is unsteady because it is in adjustment phase. The occurring of rockburst is the greatest energy shock in this phase;and after the rockburst,the activity of microseism descends obviously which means that the calm phase after shock is starting. (2) The amplitude of the principal seism in rockburst is greater and it has distinct and extended trailing wave. In the frequency spectrum of principal seism,frequency below 20 Hz takes up considerable ratio. (3) Frequencies of the foreshocks mainly concentrate upon 40–100 Hz. The foreshock contains more low frequency components when it happens closer to the principal seism. (4) The fractal dimension values of microseismic events would decrease continuously before the big seism happens and they totally decrease to a critical value when the big seism approaches. The above achievements will be valuable for confirming warning index for rockburst prediction and enhancing discriminating the danger level of dynamic disaster.
袁瑞甫,李化敏,李怀珍. 煤柱型冲击地压微震信号分布特征及前兆信息判别[J]. 岩石力学与工程学报, 2012, 31(1): 80-85.
YUAN Ruifu,LI Huamin,LI Huaizhen. DISTRIBUTION OF MICROSEISMIC SIGNAL AND DISCRIMINATION OF PORTENTOUS INFORMATION OF PILLAR TYPE ROCKBURST. , 2012, 31(1): 80-85.
窦林名,何学秋. 冲击地压防治理论与技术[M]. 徐州:中国矿业大学出版社,2002:140-167.(DOU Linming,HE Xueqiu. Rockburst control theory and technology[M]. Xuzhou:China University of Mining and Technology Press,2002:140-167.(in Chinese))
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