关键词: 榆神矿区, 近浅埋煤层, 厚硬顶板, 强矿压防治, 微震监测

Abstract: In view of the strong mine pressure problems such as large shrinkage of 'large period' weighting support column, high stress concentration coefficient of coal pillar and poor stability under the condition of near-shallow buried multi-layer thick and hard roof in Yushen mining area, numerical calculation, microseismic and coal body stress monitoring are used to analyze and study the fracture movement of overburden rock and the pressure law of working face. The results show that: (1) In the fracture movement of overburden rock, the large 'vertical separation space' and 'bottom-up' sequential alternate collapse of multi-layer thick and hard roof breed the space-time basis of 'high + low-level combined fracture' of roof. The 'high and low layer roof combination fracture' is the key inducement of 'large period' weighting enhancement; at the same time, the spatial and temporal evolution of coal pillar stress is controlled by the fracture and collapse of multi-layer thick and hard roof. (2) In terms of mine pressure appearance, the average shrinkage under the 'large cycle' pillar of the working face can reach 945mm, the continuous distance is 12.10m, and it can be composed of 2~5 consecutive strong pressures; the stress concentration factor of roadway coal pillar reaches 1.80 ~ 2.30, and the influence range is 126 m in front of the working face to 471.3m in the rear, which has obvious characteristics of 'high strength, large range and long rising period'. Aiming at the prevention and control of strong mine pressure under this condition, the technical ideas of 'weakening low roof, optimizing fracture structure' and 'weakening high roof, changing fracture sequence' are put forward respectively, and good application results are obtained.