Journal of Mining & Safety Engineering ›› 2014, Vol. 31 ›› Issue (1): 41-48.

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Space breeding mechanism of rock burst and its microseismic characteristics

  

  • Online:2014-01-15 Published:2014-02-26

Abstract: Based on variation characteristics of “surrounding rock-coal” system during coal mining, a space breeding model of stope was established in this paper. In the model, roof, coal seam and floor was regarded as a whole system to investigate the fracture, instability and burst process of coal-rock structure. In addition, this theory was verified through microseismic monitoring in a stope with strong rock burst tendentiousness.The results show that the space breeding model can accurately describe the entire process from stable state to instability of coal-rock structure. The area with high static stress concentration is the stress basis for instability and failure of coal-rock structure. Mining operations launch the dynamic process of strong tremor and rock burst, and the dynamic load caused by roof fracture can quickly trigger the dynamic process into crack mutation stage and even lead to instability and failure of coal-rock structure. The emergence of strong tremor and rock burst depends on whether the high stress concentration area can reach high inoculation degree before it was unloaded and destroyed gradually. Crack extension stage shows the abnormal precursory information of strong tremor and rock burst, and the crack mutation stage predicts the occurrence of strong tremor and rock burst. The previous strong tremors and rock bursts in No.2 Workface of No.1-3 District show obvious breeding characteristics. Especially before the rock bursts happened on 26th, Jun and 15th, Oct, the seismic events and energies are very active, which presents a more obvious breeding characteristics.

Key words: mining engineering, rock burst, tremor, breeding model, precursory information