Pressure-relief technique and its application based on seam-cutting compensation in high-stress roadway
As the underground coal mining activities become deeper and more intensive,the ground pressure on roadway has become a significant issue hindering the safe and efficient development of coalmines.A pressure-relief approach based on seam-cutting compensation is proposed to cope with the failure of high-stress roadway.This study elucidates the pres-sure-relief mechanism and the key technical parameters with their applications by combining theoretical analysis,numeric-al simulations,and field tests.Results indicate that the proposed method does not emphasize releasing the concentrated stress by breaking coal and rock mass.Instead,it strategically uses the roof-cutting effect and broken-expansion effect of rock mass to ease dynamic and static mining loads,thereby proactively reducing the roadway pressure.Specifically,this method uses the roof cutting and the broken-expansion characteristic of rock mass to achieve the mining compensation.The upper roof is promptly supported by the bulking gangue,and the impact of dynamic loading is lessened.Meanwhile,combined with the seam-cutting effect of impeding the transition of the dynamic stress,this approach comprehensively weakens mining dynamic loads.Additionally,the seam-cutting in the roof helps maintain the integrity of coal pillar,and the pillar achieves an overall bearing.The roof cutting also minimizes the stress transmission from the mined-out area.Mining static load is therefore reduced.The seam-cutting angle and length are two key technical parameters of this ap-proach.The seam angle is designed according to the theoretical requirements to maintain the roof stability of the cutting-seam roadway,and the length should ensure that the collapsed bulking rock mass fills the mining voids.The field applica-tion in a typical high-stress roadway demonstrates that this approach effectively lowers the dynamic and static mining loads on the targeted roadway,thereby markedly improving the roadway stability.The proposed pressure-relief approach and its implementation offer a practical and novel solution to controlling high-stress roadway,paving the way for a safer and more efficient mining in modern coal mines.
coalmine roadwayhigh stressproactive pressure-reliefdynamic and static loadstechnique application
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