针对地下金属矿山深部硬岩强度高，掏槽难度大，掘进效率低下的问题，以首钢杏山地下铁矿巷道掘进项目为背景，基于数码电子雷管精准逐孔起爆，提出针对直眼桶形掏槽爆破的掏槽区孔内分段与孔间、孔内延时相结合的分阶段爆破方案。采用数值模拟以及现场试验方式，在现场原传统方案的基础上，对掏槽区炮孔进行孔内分段、孔间以及孔内微差起爆的分阶段起爆设置。通过LS-DYNA数值模拟软件建立掏槽区三维模型，设置了原传统方案和3种分阶段方案进行模拟计算，对比分析了原传统爆破方案和分阶段方案在掏槽区的有效应力峰值演化情况。数值模拟结果表明：采用孔间短延时分阶段爆破方案能够改变有效应力峰值波动形态，与原传统方案相比，掏槽区沿炮孔方向岩体的有效应力峰值状态提升40%～57%，炮孔底部0～30 cm半径岩体有效应力峰值状态提升幅度在84%～92%。在数值模拟结果的基础上，开展了现场试验验证，现场试验表明：在矿石点位掘进中，采用孔间短延时微差起爆能够改善碎石挤死的现象，采用孔内短延时微差起爆能够提高抛掷能力，改善上段炮孔爆破后产生碎石的抛掷效果，避免影响后续炮孔爆破，在硬岩爆破中二者结合可以明显改善爆破效果，掏槽进尺提高28%；在岩石点位掘进中，采用孔间短延时，孔内长延时设置能获得良好的掘进效果。

In response to the challenges of high rock strength in deep underground metal mines, difficulty in slotting, and low efficiency in excavation, based on the tunneling project at Xingshan Underground Iron Mine of Shougang Corporation, and utilizing precise per-hole blasting with digital electronic detonators, we propose a phased blasting scheme for slotting areas of straight-eye barrel-shaped grooves, combining segmentation within and between holes, as well as delays within each hole. In combination with numerical simulations and field tests, it presents a trench domain gradient detonation configuration with differential detonation in the hole area, between holes and within holes on the basis of the original conventional scheme, builds a three-dimensional(3D) model of the trench domain μsing LS-DYNA numerical simulation software, sets up the original conventional scheme and three gradient schemes for modelling, and provides a comparative analysis of the evolution of the effective peak stress in the dredged-trench zone for the original conventional blasting solution and the staged solution. The results of the numerical simulations show that the μse of short-delay inter-hole blasting can change the fluctuation pattern of the peak effective stress, and compared to the original conventional scheme, the peak effective stress state of the rock in the dredged-trench zone along the direction of the shell hole is increased by 40% to 57%, while the peak effective stress state of the rock in the radiμs of 0-30cm at the bottom of the shell hole is increased by 84% to 92%. In addition to the numerical simulation results, field experiments were carried out to verify the results. It is clear that the combination of short-delay differential detonation between holes can improve debris crowding in mine excavation, and short-delay differential detonation within holes can improve throwing capacity, improve debris throwing after blasting in the upper part of the shell hole, and avoid affecting the blasting of subsequent shell holes. Incorporating the two in hard rock blasting can significantly improve the blasting effect and increase the hollowing progress by 28%. And better results can be obtained in rock point-excavation by μsing short delay between holes and long delay within hole settings. The results of this paper could provide a reference for similar mine production.