基于LS-DYNA模拟的准直眼掏槽爆破技术研究

为了选出较好的爆破效果方案,有效提高巷道掘进速度,利用有限元分析软件对准直眼掏槽爆破技术进行数值模拟。通过控制药量多少和有无中心孔,对槽腔内和自由面上的有效应力比较得到:有中心孔和增大药量均可提高爆破有效应力;依据此装药结构和爆破工艺条件,炮孔中存在一个距孔底约1.25m高度的影响爆炸有效应力分布的高度阈值;两楔形孔连线上越靠近孔口连线中点,自由面上有效应力越来越小,与双孔爆破应力叠加理论模型分析给出的结论吻合。据炮孔底部有效应力等值线分布得到,准直眼掏槽更加适用于岩石硬度较大、炮孔深度较深的掏槽爆破。

Research on Quasi-parallel Cutting Blasting Technology Based on LS-DYNA Simulation

In order to select a better blasting effect scheme and effectively improve the roadway excavation speed, the finite element analysis software was used to numerically simulate the quasi-parallel cutting blasting technology. By controlling the amount of dosage and whether or not there is a central hole, the effective stress in the cutting cavity and on the free surface is compared: the center hole and the increase of the dosage can increase the effective stress of the blast; According to the charge structure and blasting process conditions in this paper. There is a height threshold value about 1.25m from the bottom of the hole in the blasthole, affect the distribution of effective stress of the explosion; Near the midpoint of the connection line, the effective stress on the free surface is getting smaller and smaller, which is consistent with the conclusion given by the theoretical model analysis of the double-hole blasting stress superposition. According to the distribution of the effective stress contour at the bottom of the blasthole, the quasi-parallel cutting is more suitable for the blasting of rock with a larger hardness and a deeper blast hole.