孔底准真空间隔装药的爆破效果试验研究

Experimental Study on Blasting Effect of Quasi Vacuum-decking in Hole Bottom

采用相似模拟试验对孔底准真空间隔装药的爆破效果进行研究。通过高速应变测试、爆破振动测试、爆破漏斗容积测量及块度测量分析爆破效果。相同实验条件下对比水、空气、准真空三种间隔装药方式:准真空所测得的平均峰值最小为1.67με;准真空间隔装药方式爆破引起的爆破震动速度峰值小于空气间隔及水间隔;空气间隔与准真空间隔装药方式爆破后,均能获得比连续装药方式更大的漏斗体积;准真空间隔装药方式爆破时爆出的块度大小集中在块度半径R为10~12.5 mm之间,块度均匀性较其他间隔装药方式好。得到以下结论:孔底准真空间隔装置的使用能延长爆破作用时间,增大爆破漏斗体积,减少大块率且准真空层与埋药深度之比在37.5%~50%范围内,爆破能量利用率大。

The blasting effect of quasi vacuum-decking at the bottom of hole is studied by similarity simulation. The blasting effect is analyzed by means of high speed strain test, blasting vibration test, blasting crater volume meas- urement and fragmentation measurement. Under the same experimental conditions, contrasting water, air, quasi vaeu- um three types interval charging,the minimum average peak of quasi vacuum-decking is 1.67 I.Le. The peak velocity of blasting vibration caused by blasting in quasi vacuum-decking is smaller than that of air gap and water interval. The blasting of air spaced charge and quasi vacuum-decking, both can get bigger crater volume than continuous char- ging. After quasi vacuum-decking blasting, the fi＇agmentation size is concentrated in the block radius R from 10 mm to 12.5 ram, and the uniformity of the block is better than that of other interval charging. The following conclusions are obtained ,the use of the quasi vacuum-decking at the bottom of the hole can prolong the blasting action time, increase the volume of the blasting crater and reduce the lump rate. Furthermore, when the ratio of the quasi vacuum layer to the buried depth is within the range of 37.5% to 50% ,the utilization rate of the blasting energy is large.