Mitigating rock burst hazard in deep coal mines insight from dredging concentrated stress: A case study

Abstract

Concentrated stress in deep coal seam is the decisive factor leading to the occurrence of rock burst, and the different stress sources cause high stress in coal seam. To fundamentally reduce the concentrated stress in coal seam that can easily cause rock burst, this paper uses the 5305 working face in Xinhe, Shandong Province, as an example for analysis. The evolution law of high stress concentration areas (coal burst-prone zones) is analysed in coal seam during face mining, combined with the occurrence characteristics and mining conditions of the working face. The stress sources that cause different coal burst-prone zones in working face are determined. Aimed at different coal burst-prone zones, a targeted prevention-control method is proposed and includes cutting off stress paths, removing stress sources and eliminating stress sources; this method is applied to the Xinhe Coal Mine. The results show that a high static load is the main cause of rock burst in the working face of coal pillar groups. The concentrated stress of coal seam in the working face of 5305 is effectively reduced by adopting dredging concentrated stress prevention method. Field monitoring shows that the microseisms and stress in the coal seam are within a reasonable range during the whole mining process, and the occurrence of rock burst in the working face is successfully avoided.