分层不掏槽爆破在下山巷道掘进中的试验研究

Test and Study on Slicing No cut Blasting Applied to Heading of Mine Dip Roadway

针对煤矿下山巷道钻爆法掘进中普遍存在的循环进尺小、炮孔利用率低、爆后矸石堆积工作面、留底严重等问题,提出一种分层不掏槽爆破技术。基于高速摄影和掏槽破岩理论,通过试验对比,分析了直眼掏槽、楔形掏槽、不掏槽3种形式的爆破破岩效果优劣;并使用ANSYS/LS DYNAY有限元软件,对实际工程中不掏槽单孔爆破时的炮孔内岩石连续损伤演化累积过程进行数值模拟。在实际煤矿下山巷道掘进施工中,采用楔形加直眼掏槽和分层装药、同时起爆、不掏槽2种爆破方案,进行现场试验。通过对掘进进尺、炮孔利用率、光爆效果、抛渣距离、矸石块度等指标的对比分析,评价设计方案,优选出综合指标最佳的爆破方案。采用此方案,能将月进尺提高13%以上,并能大大提高出矸效率。

According to a small circulated footage and a low utilization of the blasting boreholes generally existed in the drilling and blasting heading of the tip roadway in the coal mine as well as the waste rock pile left in the heading face after the blasting,many rock waste left on the ground floor and other problems,a slicing no cut blasting technology was provided.Based on the high speed photography and the cut blasting rock breaking theory,with the comparison between the tests,the paper had an analysis on the advantages and disadvantages of the three type blasting rock breaking effects with the parallel cut,wedge cut and no cut.The ANSYS/LS DYNAY finite element software was applied to the nume-rical simulation on the continued damage evolution accumulation process of the rock in the blasting borehole during the no cut single borehole blasting of the actual engineering.In the heading of the tip roadway in the actual coal mine,a site test was conducted with two blasting planes of the wedge and parallel cut and layer charge,synchronous detonation and no cut.With the comparison analysis on the heading footage,borehole utilization rate,smooth blasting effect,waste rock throwing distance,waste rock size and other indexes,the design plan was evaluated and the optimum plan with the comprehensive indexes was optimized.With the optimized plan,the month heading footage could be improved over 13%and the waste rock discharging efficiency could be highly improved.