光面爆破是超长山岭隧道掘进常用的一种爆破技术,本文以深圳市东歌区间隧道施工为工程背景,针对相关爆破参数对光面爆破效果的影响,构建了不同线装药密度下的数值模型,通过对模拟结果的分析,确定了适合本爆破工程的最佳线装药密度。结果表明:炮孔两侧光爆层区域和围岩层区域的主裂纹长度会随着线装药密度的增大而增大,在线装药密度为0.08 kg/m时,炮孔连线上裂纹贯穿效果不好,存在部分欠挖现象,线装药密度为0.12 kg/m时,爆破过程中裂纹长度最长,对周边岩体的损伤较大;通过数值模拟多次分析计算,确定线装药密度为0.10 kg/m时爆破效果较好,光面爆破轮廓线较为整齐,半孔痕率较高。研究成果可为同类工程提供借鉴。

Smooth blasting is a commonly used blasting technique for the excavation of ultra-long mountain tunnels. This paper takes the construction of the Dongge section tunnel in Shenzhen City as the engineering background. It investigates the effect of relevant blasting parameters on the smooth blasting effect. Numerical models with different linear charge densities were established. Through analysis of the numerical simulation results, the optimal linear charge density suitable for this blasting project was determined. The results indicate that: The length of the main cracks in the smooth blasting layer on both sides of the blast holes and in the surrounding rock mass increases with the increase of linear charge density. At a linear charge density of 0.08 kg/m, the effect of crack penetration along the blast hole alignment is not good, with partial under-excavation observed. When the linear charge density is 0.12 kg/m, the crack length during the blasting process is the longest, resulting in greater damage to the surrounding rock mass. Through multiple analyses and calculations using numerical simulation, it was determined that a linear charge density of 0.10 kg/m yields better blasting effects. The outline of the smooth blasting is neater, and the half-hole rate is higher. Theoretical derivation and calculation results can provide reference for similar engineering projects.