坚硬顶板切顶卸压无煤柱开采技术研究

为解决唐山沟煤矿留煤柱开采存在的巷道掘进率高、煤炭资源浪费严重、留设煤柱造成应力集中存在安全隐患等问题，采用数值模拟和现场试验的方法，对坚硬顶板条件下切顶卸压无煤柱开采技术的切顶高度、切顶角度、爆破钻孔间距等关键参数进行研究。数值模拟结果表明：采用双向聚能爆破技术可以起到顶板卸压作用，而且随着切顶高度的增加，其切顶卸压效果更为明显；切缝存在明显的角度效应，不但能够影响采空区顶板垮落，还能够影响应力增高区分布。现场爆破试验表明，当钻孔间距为600 mm时，爆破孔贯通效果最好，对围岩的破坏最小。采用切顶高度6 m、切顶角度15°、爆破钻孔间距600 mm的技术参数，在唐山沟煤矿8820工作面回风巷进行沿空留巷现场试验取得了良好效果。

Research on Pillarless Mining Techenique by Top-cut Pressure Relief of Hard Roof

In order to solve the potential safety problems of high roadway drivage ratio, serious coal resources waste and the strss concentration in coal pillar mining in Tangshangou Mine, study was carried out in this paper on some key parameters such as the top-cut height, the top-cut angle and the blasting hole spacing of the pillarless mining technology by top-cut pressure relief of the hard roof through the numerical simulation and on-the-spot tests. The numerical simulation results showed that the bilateral cumulative blasting technology can play the roof pressure relief effect, and with the increase of the top-cut height, the top-cut pressure relief effect became more obvious; the cut slot has an obvious angle effect, which can not only affect the caving of the gob roof, but also affect the distribution of the stress concentration zone. The field blasting tests showed that when the hole spacing was 600 mm, the penetrating effect of the blasting hole was the best, and the damage to the surrounding rock was minimum. Under the conditions of the top-cut height of 6 m, top-cut angle of 15° and hole spacing of 600 mm, tests were carried out in the gob-side air-return way drivage of 8820 working face in Tangshangou Mine, and good results were achieved.