关键词: 切顶卸压, 超前支承压力, 深孔爆破, 工作面末采, 切顶关键参数, 极限平衡理论

Abstract: In view of the deformation and instability phenomenon of the surrounding rock in the main roadway in the mining area caused by the mining operation after the working face enters the final mining stage, based on the mechanical model of the distribution of the advanced bearing pressure, the limit equilibrium theory and the half-plane solution method are used to theoretically calculate the peak value of the advanced bearing pressure. The location, the influence range and the stress at the main road in the mining area are analyzed. The main reason for the stress increase in the main road is that the overlying stratum on the working face is relatively complete, which intensifies the forward transmission of the advanced bearing pressure. Therefore, it is proposed to use deep hole pre-split blasting technology, and use the penetration of blasting cracks to form structural weak planes, thereby destroying the transmission path of the advanced bearing pressure, so as to reduce the impact range of working face mining and improve the stability of the surrounding rock in the roadway. ;According to the engineering geological conditions, quantitative analysis selects the key parameters of blasting roof cutting, and uses numerical simulation to verify the rationality of the plan; through on-site industrial test and mine pressure monitoring data analysis shows that: under blasting roof cutting conditions, 5#, 8# The approaching amount of the roof and floor of the measuring point is reduced by 41% and 55.5% respectively, and the moving amount of the two sides is reduced by 68.1% and 74.8% respectively, indicating that this scheme can improve the stress environment of the main roadway in the mining area and reduce the influence range of the advanced bearing pressure.