水力冲孔过程就是煤体破坏剥落,应力状态改变,瓦斯大量释放的过程。水力冲孔的实质就是:首先利用高压水射流破碎煤体在一定时间内冲出大量煤体,形成较大直径的孔洞,从而破坏煤体原应力平衡状态,孔洞周围煤体向孔洞方向发生大幅度位移,促使应力状态重新分布,集中应力带前移,有效应力降低; Hydraulic punching process is the destruction of coal flaking, stress changes, a large number of gas release process. The essence of hydraulic punching is as follows: Firstly, using high-pressure water jet to crush a large amount of coal and break the large amount of coal in a certain time to destroy the original stress equilibrium state of the coal, the coal body around the hole is large toward the hole Amplitude displacement, prompting the redistribution of stress state, concentrated stress band forward, the effective stress reduction;