关键词: 超大采高, 周期来压, 矿压规律, 覆岩活动, 微震监测

Abstract: Aiming at the problem of strong ore pressure in super-high mining face with shallow buried thick hard roof, based on support pressure and in-situ microseismic overlying rock monitoring data, the ore pressure and overlying rock activity regularity in Caojiatan 10m super-high mining face were studied. The results show that the first pressing step of the basic top of 10m super-high mining face is 49.35 m, the average pressing step of periodic working face is 21.89 m, and the average dynamic load coefficient is 1.49. The working face has the phenomenon of "size cycle" to press, and during the big cycle to press, the working face to press step increases significantly. The working resistance of the support increases not significantly during non-pressure period, but significantly during periodic pressure period. The living column of the support has obvious shrinkage, especially during the "big cycle" period, the average and maximum shrinkage of the column reach 686.12 mm and 1321.35 mm respectively. It has the characteristics of long pressing step, long pressing duration, frequent pressing, strong dynamic load ore pressure and severe coal wall sheet. The active area of microseismic events is located in the working face trend, 0~130 m away from the center of the working face, where 110~130 m is the peak area. The 40~60 m microearthquakes in the roof of coal seam have low frequency but high energy, which is the dominant rock formation of strong ore pressure. The spatial and temporal distribution of microseismic events is in good agreement with the rule of ore pressure. High-energy microseismic events usually occur before the ore pressure appearance of the working face, and have a good correspondence with periodic pressure. The reliability or matching degree of ore pressure prediction is relatively high.