为了研究采空区上方突发大面积的顶板垮落现象,结合昊达煤矿采空区顶板不能自然垮落且不具备良好作业条件的情况,提出了一种新的采空区顶板强制放顶方法——地表钻孔预留采空区顶板强制放顶爆破方法,包括采用3项关键技术:从地表向下垂直钻孔,不扩孔进行强制放顶爆破;采空区顶板预留的安全厚度由集中药包爆炸后内部作用裂隙区半径的计算公式算出;炮孔底部装填燃烧过的蜂窝煤碎渣且孔内分3段起爆,减少对炮孔底部岩石的破坏。工程实践证明,地表钻孔预留采空区顶板强制放顶爆破方法可有效预防采空区顶板大面积垮落,降低了人员作业风险,实现了煤矿安全生产。
In order to study the phenomenon of a large area collapse of gob roof,combined with the situation that the roof of the coal mine cannot collapse naturally and have no good working conditions,a new gob roof forced caving method called"Ground drilling reserved gob roof forced caving blasting"is put forward.Three key techniques include drilling from the surface downwards and without forced expansion of the hole,the safety thickness of the gob roof is calculated by calculating the radius of the internal friction zone after the explosion of the concentrated charge and the bottom of the blasting hole is filled with the burned honeycomb briquet slag and the hole is divided into three sections to initiate to reduce the damage to the bottom rock.The engineering practice proves that the " Ground drilling reserved gob roof forced caving blasting" method can effectively prevent a large area collapse of gob roof,reduce the risk of personnel operation and realize the safe production of coal mine.