Features of microseismic events and precursors of coal bumps in
underground coal mining with hard roof
ZHAO Yi-xin1,2,3，JIANG Yaodong1,2, WANG Tao3，GAO Feng3，ZHOU Kun3，
(1. State Key Lab of Coal Resources and Safe Mining，China University of Mining and Technology(Beijing)，
Beijing 100083，China; 2. State Key Laboratory for Geomechanics and Deep Underground Engineering, China
University of Mining and Technology, Beijing 100083, China ; 3. School of Mechanics and Civil Engineering，
China University of Mining and Technology (Beijing)，Beijing 100083，China)
Abstract：The characteristics of coal bumps are analyzed based on the microseismic
data from No.8935 panel in Xinzhouyao coal mine, Shanxi Provence，China. The
geology of this panel is characterized by the thick sandstone roof and hard coal seam,
both with relative higher stiffness and strength. In order to investigate the mechanism
and precursors of coal bumps occurred in No.8935 panel, the locations of
microseismic, the relationship of microseismic energy and frequency and the
spectrum of microseismic signals are analyzed. The result shows that the coal bumps
in No.8935 panel were mainly induced by the seismic caused by roof failure. The coal
pillars near the goaf are more easily to bump. The statistics results indicate that the
coal bumps were mainly occurred in the gate road near the pillar, less than 50m ahead
of working face and located in the hard roof adjacent with coal seam. Moreover, the
frequency, energy, b-value and frequency spectrogram of microseismic events were
found to decrease before coal bumps. It was also found that the frequencies of the
microseismic events before coal bumps mainly concentrate upon 5~60Hz. The sudden
decreasing of frequency and increasing of amplitude of microseismic events can be
regarded as a precursor of coal bumps.
Key words：coal bumps；microseismic；b-value；spectrum；precursor
Brief Bio:
Yixin ZHAO
Associate Professor, Director of Academic Committee Office of State Key Laboratory of Coal
Resources and Safe Mining ;China University of Mining and Technology (Beijing)
Prof Yixin Zhao obtained BE and PhD in China University of Mining and Technology,
China. He worked as visit research fellow in Queen’s University (Canada) and senior
geotechnical engineer in SRK Consulting, China. He has about ten years experience in
rock mechanics. Now, he is an associate professor in China University of Mining and
Technology (Beijing). His interests are in the areas of rock mechanics, numerical
simulation, microstructures of coals and related mechanical properties.