【摘要】 玉溪煤矿1301首采工作面老顶为一层坚硬厚实的中粒砂岩,在工作面切眼内实施工作面回采前深孔预裂爆破,通过对顶板预裂前后老顶断裂极限跨距的理论分析、回采初期顶板垮落情况、工作面综采支架工作阻力等的综合分析,发现顶板爆破有效缩短了初次来压步距,减小了悬顶面积,防止了大面积垮落时工作面瓦斯超限,减弱初次来压对支架的冲击破坏性。更多还原

【Abstract】 The main roof of the 1301 first working face in Yuxi Coal Mine is a layer of hard and thick medium-grained sandstone, through the theoretical analysis of the fracture limit span of the main roof before and after the roof pre-crack, the comprehensive analysis of the roof collapse at the initial mining stage and the working resistance of the fully-mechanized support in the working face, the roof blasting effectively shortens the first weighting step, the utility model reduces the overhanging roof area, prevents the gas exceeding the limit in the working face when the large area collapses, and weakens the impact destructiveness of the first weighting on the support.更多还原