Abstract: Massive mining-induced seismic events may appear before the occurence of strong tremor, which is important information for the evaluation of rock burst danger. In this paper, based on the seismic monitoring by SOS Seismological Observation System installed in No.10 Coal Mine of Pingdingshan Mining Area, the concentration index of seismic source was constructed by the principal component analysis technique, to study the distribution characteristics of seismicities, and the variation rules of seismic energies and events numbers were also analyzed. The results show that: 1) Strong tremors mainly concentrated in the coal pillar regions formed by stop lines of multi coal faces in coal seam group; 2) Before strong tremor happened, the total energy of seismic events may be active firstly, then presents obvious decreasing trend, while the event numbers always keep in a relatively high level; 3)The larger the event number, and the smaller the concentration index of seismic source, the higher occurrence possibility of strong tremor. Based on the precursory rules of above parameters, the grading standard system of burst danger for No.10 Coal Mine of Pingdingshan Mining Area were built by accumulation method to evaluate the burst danger level. Application results show that the evaluation system can be successfully used to evaluate rock burst danger.

Key words: rock burst, high accuracy seismological observation system, active period, principal component analysis, concentration index of seismic source