关键词: 冲击地压, 坚硬顶板, 单双巷顶板爆破, 爆破高度, 应力演化

Abstract: The hard roof is an important factor affecting the impact risk of the working face, and blasting technology is often used in practice to pre-split and relieve pressure on the working face roof. This article takes the 7202 working face with a hard roof above the 3rd coal seam of a certain mine as the object, and uses methods such as theoretical analysis, numerical simulation, and industrial experiments to study the stress evolution of surrounding rock and the law of mining tremors under different blasting heights, single and double roadway roof blasting in the working face. The results show that when using single or double roadway blasting for low level sub-key stratum, the higher the blasting height, the lower the peak stress of the surrounding rock in the roadway, and the pressure relief effect is positively correlated with the blasting height. However, when using double roadway blasting and increasing the blasting height to more than 6 times the mining height, there will be a phenomenon of stress increase in the central area of the working face, and the shorter the working face, the more obvious the stress increase. During the initial mining stage of the 7202 working face, when single roadway roof blasting with a height of 3 times the mining height was carried out, the microseisms were mostly concentrated in the roadway area, and the pressure relief effect was moderate. After changing to double roadway roof blasting and increasing the blasting height to 6 times the mining height, the microseisms were mostly concentrated in the central area of the working face, without the occurrence of high-energy mining tremors. The number of stress monitoring warnings was also significantly reduced, and the pressure relief effect in the roadway area was good.