岩巷掘进准直眼掏槽爆破模型试验研究

摘要

In order to better apply the technique of quasi-parallel cutting blast, based on similarity theory, the similarity criterion of model test of quasi-parallel cutting is established. The physical model tests of quasi-parallel cutting are carried out. Taking the face spacing, array pitch and angle of main cut holes as the key factors, the orthogonal tests are conducted. The results of range analysis show that: (1) The face spacing of main cut holes has the maximum effect on cut depth, next is the angle, and the minimum is the array pitch. (2) For cavity volume, the face spacing of main cut holes has the maximum effect, next is the array pitch, and the minimum is the angle. The results of variance analysis show that: (1) The face spacing of main cut holes has a very significant effect on cut depth, the angle has a significant effect on cut depth, while the array pitch has no effect on cut depth. (2) The three factors all have very significant effects on cavity volume. Besides, the model tests are conducted under the condition that the angle of main cut holes is greater than 85°. The test results show that the influence of angle of main cut holes on quasi-parallel cutting blast is very apparent. Meantime, the test results prove the analysis of corner span between quasi-parallel hole and the free face. The optimization blast parameters of model test are obtained as following: the face spacing of main cut holes is 150 mm; the array pitch of holes is 70 mm and the angle of main cut holes is 83°. The good blast effects are achieved by using the transformation scheme from the above scheme in field engineering.%为了更好地应用准直眼掏槽爆破技术,基于相似理论,建立准直眼掏槽模型试验相似准则,进行准直眼掏槽方式的物理模型试验.以主掏槽孔孔口间距、炮孔排距和主掏槽孔倾斜角度为主导因子进行正交试验.极差分析结果表明:对于掏槽深度,主掏槽孔孔口间距的影响最大,主掏槽孔倾斜角度其次,炮孔排距影响最小；对于槽腔体积,主掏槽孔孔口间距影响最大,炮孔排距的影响其次,主掏槽孔倾斜角度影响最小.方差法分析结果表明:主掏槽炮孔孔口间距对掏槽深度有极为显著的影响,主掏槽炮孔倾斜角度有显著影响,而炮孔排距无显著影响；主掏槽炮孔孔口间距、炮孔排距和主掏槽炮孔倾斜角度对槽腔体积均有极为显著的影响.此外,开展主掏槽孔倾斜角度大于85°的模型试验,结果表明:主掏槽孔倾斜角度对准直眼掏槽爆破的影响极为明显.该结果同时也验证准直眼与自由面夹角取值范围的分析.模型试验最优爆破参数为:主掏槽孔孔口间距150 mm,炮孔排距70 mm,主掏槽孔倾斜角度83°.现场应用由该模型方案所转化的现场试验方案,取得良好的爆破效果.