爆破动载下强冲击危险巷道锚杆轴力定量损失规律的试验研究

针对目前冲击地压矿井卸压爆破参数常不合理导致支护损伤，降低防冲效果的问题，采用锚杆无损检测系统在井下强冲击危险巷道进行现场原位试验研究，定量化分析了爆破动载下锚杆轴向工作阻力的定量损失规律。通过分析，获得了不同药量的爆破导致锚杆轴力损失的影响程度及空间范围。发现了爆破药量不小于6 kg时，随至震源距离的增大锚杆轴力的平均损失率基本呈乘幂关系衰减，但也存在局部突增的可能。同时爆破下锚杆轴力损失是与锚杆方位相关的，距震源越近与锚杆方位的相关性越显著。随着爆破药量的增大锚杆轴力损失率升高，药量越大升高速度越快。通过分析发现，众多影响因素中至震源的距离和锚杆方位只是表层因素，而爆破药量和煤体性质才是核心因素，并且核心因素间也存在相互影响。综合考虑爆破下锚杆轴力损失规律以及煤层爆破的卸压效果，优化了内蒙某矿强冲击危险巷道爆破卸压参数，现场应用效果理想。由此建立了冲击地压矿井煤层卸压爆破参数优化的现场原位试验方法。

Experimental research on axial force quantitative loss law of anchor boltin blasting in high impact danger roadway

In terms of the problem that in rockburst mine the pressure release blasting with unreasonable parameters presently leads to support damage,and reduces the effect of rockburst prevention,using bolting quality non-destructive testing technology,the axial force quantitative loss law of anchor bolt in blasting in high impact danger roadway was quantitatively analyzed.The analysis revealed the scope and extent of bolts axial force loss caused by blasting with varying doses of explosive.And when blasting dose is equal to or greater than 6 kg,axial force loss attenuates exponentially with the distance from the explosive center,but there are also possible that partial loss suddenly increases.Axial force loss rate in blasting is associated with anchor position,which is more obvious when the distance between source and anchor position is shorter.With the increase of explosive charge,the axial force loss rate of bolt anchor increases,which is faster when the charge is larger.Considering the axial force loss law of the anchor of blasting and the effect of blasting pressure relief in coal seam,the result of blasting parameter optimization is 12 m hole depth and 6 kg charge in the high impact danger roadway of a mine of Inner Mongolia,the effect of its application is ideal.Also,the in-situ measurement method of pressure relief blasting parameter optimization in coal mine was established.