Frontiers in Earth Science (Nov 2024)
Study on the mining response law and coal burst risk assessment of an isolated working face
Abstract
With the increasing demand for coal resources and the unreasonable arrangement of subsequent working faces, mining activities in isolated working faces are more likely to induce coal burst accidents. In this study, the minimum distance principle is utilized as the risk assessment indicator and the quantitative theory is introduced to evaluate coal burst risk in isolated working faces. Through a case study in 1,304 isolated working face of Yangcheng Coal Mine, the key factors affecting the risk of coal burst were identified, and a three-dimensional coal burst risk assessment model was constructed to evaluate the risk of the isolated working face. The results show that as the working face advances, the abutment pressure and elastic strain energy density in front of the working face increase to the peak value in a positive exponential relationship at first and then decrease to in situ stress, which presents an upward convex trend. Under different excavation steps, the concentration coefficient of the peak stress gradually increases. The influence range of the abutment pressure of the working face gradually increases. Compared with one-dimensional and two-dimensional evaluation functions, the three-dimensional function significantly improves the accuracy of risk assessment and successfully identifies strong coal and gas outburst risks. Additionally, the model not only enhances the precision of risk assessment but also quantifies the assessment parameters.
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