摘要
针对软岩巷道掘进中爆破扰动诱发拱顶超挖的技术难题,提出预裂-光面协同爆破参数优化方法。基于波阻抗理论分析,揭示了预裂缝与围岩之间因波阻抗差异形成高反射系数界面。当应力波传播至此界面时,其大部分能量被反射,仅少量透射,从而显著衰减了应力波强度。这一过程将原本瞬态的剧烈冲击能量,转化为在毫秒时间尺度上平缓释放的荷载,有效阻断了后续应力波的能量叠加与岩体内的损伤累积,提升了岩体的动态稳定性。数值模拟结果表明:相较于传统光面爆破,协同方案将损伤区限制在预裂缝内侧,拱顶损伤深度降至0.3 m,并显著降低峰值振动速度(PPV),荷载模式由“陡升缓降”转变为上升平缓、峰值滞后的“毫秒级缓释”。现场试验在姑山铁矿-350 m水平高岭土化闪长玢岩巷道进行,应用优化后的协同爆破方案有效控制了轮廓成形,软弱夹层区域围岩保持完整,未发生掉块或垮塌。研究证实预裂-光面协同爆破通过应力屏障效应与参数优化,可显著降低软岩巷道爆破损伤与振动,有效控制超挖。
To address the technical challenge of blast-induced overbreak at tunnel crowns during soft rock roadway excavation,this study proposes an optimized presplit-smooth blasting synergistic method.Theoretical analysis grounded in wave impedance principles demonstrates that the wave impedance disparity between pre-split cracks and surrounding rock creates a high-reflectivity interface,fundamentally altering stress wave propagation dynamics.When the stress wave reaches this interface,most of its energy is reflected,with only a small portion transmitted,resulting in substantial attenuation of wave intensity.This phenomenon transforms the initially transient,intense impact energy into a millisecond-scale,gradually released load,effectively mitigating energy superposition from subsequent stress waves and preventing cumulative damage within the rock mass,thereby significantly improving the dynamic stability of the geological structure.Numerical simulation results demonstrate that the synergistic method outperforms conventional smooth blasting by effectively confining the damage zone within the presplit fracture boundary,resulting in a remarkable reduction in crown damage depth to 0.3 m.Furthermore,this approach substantially decreases peak particle velocity(PPV)while transforming the loading profile from a transient sharp-rise/slow-decay′impact to a more controlled millisecond-level delayed-release′pattern featuring gradual pressure buildup and deferred peak intensity.Field implementation of the optimized synergistic scheme in the kaolinized diorite porphyry roadway at the-350 m level of the Gushan Iron Mine demonstrated exceptional contour control,maintaining intact surrounding rock in weak interlayer zones without spalling or collapse.The study verifies that the presplit-smooth blasting synergistic method,leveraging stress barrier effects and meticulous parameter optimization,achieves a substantial reduction in blast-induced damage and vibration while effectively mitigating overbreak in soft rock roadway excavation.
作者
黄刚
陈焕轩
王亮
陈晨
杨明
黄照玮
HUANG Gang;CHEN Huan-xuan;WANG Liang;CHEN Chen;YANG Ming;HUANG Zhao-wei(School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China;Gushan Mining Co.,Ltd.,Ma'anshan Iron and Mine Resources Group,Dangtu 243181,China)
出处
《爆破》
北大核心
2026年第1期49-57,212,共10页
Blasting
基金
国家自然科学基金资助项目(52109165)。
关键词
软岩巷道
预裂爆破
光面爆破
数值模拟
超挖控制
soft rock roadway
presplitting blasting
smooth blasting
numerical simulation
overbreak control
