Research on influence of delay time on the energy release of parallel cut blasting

XU Qinming; CHEN Yequn; HUANG Xinxu; YANG Saiqun; LI Hongwei

doi:10.3969/j.issn.1674-3970.2025.01.005

Abstract：With the widespread use of electronic detonators in blasting projects,delay blasting technology has become a popular research direction.Based on the blasting project of a tunnel excavation in an iron mine in Anhui Province,numerical simulation is used to investigate the influence of delay time on energy release in parallel cut blasting.By ANSYS/LS-DYNA,a parallel cut blasting simulation is conducted to analyze the effective stress distribution at key points,the energy evolution and crack propagation process during blasting,thereby,to optimize the reasonable delay time.Subsequently,field experiments are carried out to select the optimal hole to hole delay time by comparing post-blasting lump rate and total vibration energy.The research results show that when the delay time between holes is 15 ms and 20 ms,the effective stress peak value and the kinetic energy of the rock at the selected measuring point are significantly greater than those at other delay times;MATLAB image processing technology is used to process the rock slice damage diagram obtained by numerical simulation,and it is found that the rock damage shows a trend of first increasing and then decreasing with the increase of the delay time between holes in the parallel cut,and the degree of rock damage is the largest at 20 ms.A comprehensive analysis of the post-blasting lump rate and blasting vibration effect is conducted,and the parallel cut achieves the best effect when the delay time between holes is 20 ms.