电子雷管在岩巷爆破中掏槽孔微差时间试验研究及数值模拟

Experimental Study and Numerical Simulation on Micro-difference Time of Cutting Hole of Electronic Detonator in Rock Roadway Blasting

为研究直眼掏槽爆破掏槽孔与辅助孔间延期时间对掏槽爆破效果的影响,通过电子雷管的模型试验对不同延期条件下的槽腔形成过程和特点进行了研究。试验采用高速摄影仪对试块槽腔的形成过程进行观测,并利用有限元分析软件ANSYS/LS-DYNA对槽腔裂纹扩展进行了数值模拟分析。结果表明:①在本模型试验条件下,延期时间为1~3 ms时掏槽孔与辅助孔之间的爆炸能量相互作用最紧密,并为辅助孔起爆提供了新自由面,降低了辅助孔起爆受到的夹制作用,爆破效果最佳。②同时起爆时,相邻掏槽孔与辅助孔之间的岩体比掏槽孔包含的槽腔岩体破碎更充分。延期1 ms起爆时,掏槽孔与辅助孔之间的岩石受辅助孔爆炸冲击波作用瞬时移动速度达到最大,辅助孔起爆产生的裂隙范围也最大,掏槽效果最佳。③掏槽孔起爆超过1 ms后对槽腔岩体的影响逐渐消失,此时起爆辅助孔不利于掏槽孔与辅助孔之间爆炸能量相互叠加,降低了掏槽爆破效果。

In order to study the effect of the delay time between the cutting hole and the auxiliary hole on the cutting blasting effect,the model experiment of electronic detonator was used to study the formation process and characteristics of the cavity under different delay conditions.In the experiment,the high-speed camera was used to observe the formation process of the block cavity,and the finite element analysis software ANSYS/LS-DYNA was used to carry out the numerical simulation analysis on the crack propagation of the cavity.The results show that:①Under the experimental conditions of this model,when the delay time is 1~3 ms,the explosion energy interaction between the cutting hole and the auxiliary hole is the closest,and provides a new free surface for the auxiliary hole initiation,reduces the clamp production used in the auxiliary hole initiation,and the blasting effect is the best.②The rock mass medium between adjacent cutting holes and auxiliary holes is broken more fully than the rock mass medium in the cavity contained in the cutting hole.When the initiation time is delayed by 1 ms,the instantaneous velocity of rock movement between the cutting hole and the auxiliary hole under the blast wave of the auxiliary hole is the largest,and the crack range generated by the initiation of the auxiliary hole is the largest,so the cutting effect is the best.③The influence on the rock in the cavity gradually disappears after the initiation of the cutting hole exceeds 1 ms,and the initiation of the auxiliary hole is not conducive to the superposition of the explosion energy between the cutting hole and the auxiliary hole,which reduces the blasting effect of the cutting hole.