岩巷切缝药包楔形掏槽爆破模型试验与分析

为了研究合理的掏槽方式改善岩巷掏槽效果差、炮眼利用率低的问题,采用水泥砂浆模型对切缝药包楔形掏槽爆破进行了试验研究。共设计了4组对比试验,每组试验分别在6组不同强度的水泥砂浆模型上展开,模型炮孔数目均为6个,每个炮孔装一发8号电雷管起爆。试验结果表明,切缝药包装药结构提高了炮孔利用率、增大了槽腔体积及降低了掏槽碎块的大块率;并得到了不同强度模型最优的掏槽方式,其中80°切缝药包楔形掏槽爆破在不同强度模型下炮孔利用率、槽腔体积及掏槽碎块大块率均相差较小,用于岩性变化较大的岩巷中,可得到较好的掏槽效果。切缝药包楔形掏槽爆破利用切缝对能量的导向作用,实现裂纹的定向扩展,并提高了掏槽效果。

Model Experiment and Analysis of Wedge-Shaped Cutting Blasting with Cutting Seam Cartridge in Rock Tunnel

In order to explore the rational cutting method to improve the poor cutting and the low blasthole utilization in rock tunnel，the experimental study of wedge-shaped cutting blasting with cutting seam cartridge based on cement mortar model is conducted.A total of four sets of comparative tests are designed，and each set of test start on six cement mortar model with different intensity.One model has six blasthole，and each blasthole is charged one No.8 detonator into it.The results show that the structure of cutting seam cartridge improves the utilization ratio of blast holes，increases the cutting cavity volume and reduces the boulder yield of cutting rock fragment.The optimal cutting method for different intensity model is obtained，among，the 80° wedge-shaped cutting blasting with cutting seam cartridge has small change in different intensity of model on blasthole utilization，cutting cavity volume and the rate of chunks of cutting rock fragment.A good cutting effect can be obtained when it is used into rock tunnel with large lithology changing.The wedge-shaped cutting blasting with cutting seam cartridge can guide the direction of energy，and achieve crack growth directionally and improves cutting effect of cutting seam.