Abstract: 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: ① Under 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.② The 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.③ The 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.

Key words: mine blasting,straight hole cutting,electronic detonator,delay time,high speed photography,numerical simulation