基于槽波波速层析成像的爆破卸压效果评价方法

Testing method on the effect of blasting releasing pressure based on in-seam wave velocity tomography

工作面上覆采空区遗留煤柱造成的应力异常,给煤矿开采带来极大安全隐患,爆破是消除煤柱应力集中的常用办法,但是缺少对爆破效果进行评价的技术。分析了槽波波速与应力之间的定性关系,上覆煤柱爆破前后进行2次槽波波速层析成像,并计算2次槽波波速差值,对工作面上覆煤柱爆破卸压效果进行评价。将槽波波速成像结果与数值模拟、矿压监测结果以及回采实际情况进行了对比分析。结果表明:工作面内槽波波速与围岩应力状态具有良好的相关性;槽波波速能够有效地反映工作面内应力分布及转移情况,合理评价煤柱爆破卸压效果。

The stress anomaly caused by the coal pillar left over from the overlying goaf on the working face results in great hidden trouble to the coal mining.Blasting is a common method to eliminate the stress concentration of the coal pillar,but it lacks the technology to evaluate the blasting effect.The qualitative relationship between the wave velocity of in-seam wave and the stress is analyzed.The twice wave velocity tomography is performed before and after the overlying pillar blasting,and the difference of the wave velocity is calculated to evaluate the pressure relief effect of the coal pillar blasting on the top of the working face.The wave velocity imaging results are compared with numerical simulation,ground pressure monitoring results and actual mining conditions.The results show that the wave velocity of in-seam wave has a good correlation with the stress state of surrounding rock in the working face,and the wave velocity can effectively reflect the stress distribution and transfer,reasonably evaluate the pressure relief effect of coal pillar blasting.