厚煤层坚硬顶板预裂爆破强制放顶技术实践

本文基于伯方煤矿3205工作面开采技术条件,提出切眼爆破强制初次放顶和两巷爆破步距式放顶方案,其中切眼全长布置放顶炮孔14组,上下端头放顶孔为每组3个,其余均为每组2个炮孔;两巷放顶炮孔每组2孔,仰角为50°和70°,水平转角为50°和70°,分2层设计进行爆破强制放顶;现场观测表明,工作面初次来压和周期来压步距分别为39.2m和17.6m,来压强度小,支架阻力富裕较大,表明工作面强制放顶控制顶板具有良好效果。

Practice of Presplitting Blasting Forced Caving Technology for Hard Roof in Thick Coal Seam

Based on the mining technical conditions of 3205 working face,this paper puts forward the scheme of forced first caving by cutting blasting and step-by-step caving by two roadways,in which 14 groups of caving holes are arranged in full length,3 groups of caving holes at upper and lower ends,and 2 holes in each group;2 groups of caving holes in two roadways,50 and 70 holes in elevation angle,50 and 70 holes in horizontal rotation angle,and two layers are designed for blasting.The field observation shows that the initial weighting and periodic weighting steps are 39.2 m and 17.6 m,respectively,with low weighting strength and abundant support resistance,indicating that the roof control by forced roof caving has good effect.