深孔预裂爆破在综放工作面坚硬顶板控制中的试验研究

摘要

Aiming at the problem that it is easy to cause mine disasters because of the large roof caving step of hard roof coal face in the early mining,selecting the 8935 working face of Xinzhouyao Coal Mine as the research object,the method of deephole pre-splitting explosion weakening roof is proposed.According to the related blasting theory and the theory of mechanics,in combination with the practical condition of 8935 working face,through the analysis of the mechanism of deep-hole pre-splitting explosion weakening roof,the parameters for deep hole pre-splitting blasting are optimized,and the field tests are carried out.Experimental results showed that mine pressure appear is not sharp during the first weighting,the first caving step of immediate roof is about 13 m,and the first weighting step of basic roof is about 34 m;support working resistance slightly increases after blasting,the concentration of CH4 and CO increases for a short period of time;when the top coal falls down in time,it can recycle 33.2 m long coal.Tests show that deep hole pre-splitting blasting plays an obvious role in weakening of roof and can reduce related disasters and increase the top-coal recovery efficiency.%针对坚硬顶板工作面由于回采初期顶板垮落步距大而易引发矿井灾害的问题,选取了忻州窑煤矿8935工作面作为研究对象,提出了采用深孔预裂爆破弱化顶板的方法.依据相关爆破理论和力学理论,结合8935工作面的实际条件,通过分析深孔预裂爆破弱化顶板的机理,对深孔预裂爆破试验参数进行了优化,并实施了现场试验.试验结果显示,初次来压期间矿压显现不剧烈,直接顶初次垮落步距约为13m,基本顶的初次来压步距约34 m;放炮后支架工作阻力稍微增大,瓦斯与CO浓度存在短时间的微增;项煤垮落及时,可多回收33.2 m长的顶煤.深孔预裂爆破对顶板的弱化作用明显,可降低相关灾害的发生性,增加顶煤回收效益.