(China Coal Northwest Energy Co., Ltd., Ordos ,China)

In order to determine the reasonable mining speed of 31102 working face of Nalinhe No.2 well in Inner Mongolia and Shaanxi area based on scour-proof condition, the correlation between mining speed of 31102 working face and microseism, coal stress monitoring data, impact appearance and movement law of overlying strata is discussed through theoretical analysis and field measurement. There is a positive correlation between mining speed and the total energy and frequency of microseismic events; the overburden energy accumulated by strong mining speed can not be released in time, resulting in sudden change of stress monitoring system curve and dynamic load; the number of microseisms in production class is obviously higher than that in non-production class, and the number of microseisms in production class is usually non-production class. The number of production shifts is 3 to 5 times, and the energy statistics of production shifts is about 3 to 5 times that of non-production shifts. The site has strengthened the management of working face personnel during the production shift, strictly enforcing the restriction measures within the advanced influence range of 300 meters in front of the work; during the period of drastic change in the advance degree, especially in the period from high to low, the impact is easy to occur, the lag time is 1～3 days, and the maximum change should not exceed 5 knives; while working face mining work is maintained. When the mining distance exceeds the collapse limit of the strata, the overburden strata will rotate and subside in a large thickness, which will lead to a large increase of the surrounding rock pressure in a short time and easily induce impact. The mining speed of 31102 working face should be stable and avoided. The maximum change is not more than 5 knives without large change of propulsive degree. If the propulsive degree is zero on the same day, low-speed and stable increase of mining speed should be considered when mining again. Through the study of reasonable mining speed of No.31102 working face, the safe mining of working face is effectively guaranteed

国家自然科学基金资助项目（51764044，51364028）