低透气性煤层双孔预裂爆破增透数值模拟

Numerical Simulation of Increasing Permeability by Double Hole Presplitting Blasting in Low Permeability Coal Seam

煤层深孔预裂爆破增透技术可以有效解决低透气性煤层瓦斯难抽采问题,通过研究不同爆破方法对煤体破坏范围的影响进而确定合理的爆孔半径对提高瓦斯抽采率具有重要的意义。以潞安矿区漳村煤矿3#煤层为研究对象,采用数值模拟的研究方法研究了双孔连续爆破应力波的传播过程及对煤层影响的范围。研究结果表明:单孔爆破模型应力波的传播特性以及爆破影响范围与双孔爆破模型存在明显差异,双孔爆破应力叠加破坏煤体的范围要远于单孔爆破对煤体的影响;通过钻孔间距为5 m、8 m和10 m的两孔连续起爆模拟结果比较,确定漳村煤矿3#煤层预裂爆破两爆破孔的合理间距为8 m。

The deep hole presplit blasting AR technology can effectively solve the difficulty of gas extraction in low permeable coal seam. The influence of different blasting methods on coal body breaking was important to determine the reasonable blasthole radius. The propagation process of the continuous double holes blasting stress wave and the influence range in 3# coal seam of Lu＇an mining area were studied with numerical simulation. The research resuits indicated obvious differences on the propagation characteristics of stress wave and the blasting influence scope between single hole and double hole blasting model. The superimposed stresses of double hole blasting played more influence on the coal body breaking range than single hole blasting. By comparing the simulated results of the three borehole spacing 5 m,8 m and 10 m,reasonable distance of presplitting blasting of double hole blasting in the coal mine was obtained as 8 m.