竖井大直径空孔掏槽爆破的振动效应分析

Analysis of vibration effect and optimization of blasting parameters for large diameter empty hole blasting in shaft

大直径空孔对掏槽爆破及其振动效应有复杂的影响。以青岛地铁5号线沾化路竖井工程为背景,借助数值模拟与现场试验相结合等手段,揭示了直孔掏槽时大直径中空孔孔径和装药孔与中空孔距离的比值K对掏槽区破岩效果和地表振速响应规律的影响。研究结论表明:掏槽区爆破破岩和减振效果与K值之间存在显著的正相关性,且K值为1时大直径空孔掏槽爆破效果最为合理;采用大直径中空孔(Ф80 cm)掏槽,基于数码电子精确延时的逐孔起爆方式,可将实际工程地表质点峰值振速精准控制在0.3 cm/s以内;现场试验监测与数值模拟结果误差在8%左右,表明研究方法是合理可行的。研究结论能为城市闹市区地铁及竖井爆破振动有害效应精准控制提供依据和参考。

The large diameter empty hole has a complex influence on the cutting blasting and its vibration effect.Taking Zhanhua Road Shaft Project of Qingdao Metro Line 5 as the background,by means of numerical simulation and field test,the influence of the diameter of large-diameter hollow hole and the ratio K of the distance between charge hole and hollow hole on the rock breaking effect and the response law of surface vibration velocity in the cutting area is revealed.The results show that:the hollow zone blasting rock breaking vibration damping effect and K value is significantly positively correlated with the Kvalue of 1 for the large diameter hollow hole cavitation effect is the most reasonable;the use of largediameter hollow hole(Ф80 cm)hollow,combined with the digital electronic precision delay based on thehole-by-hole detonation can be accurately controlled in the peak vibration velocity of the surface plasma in the 0.3 cm/s;field test monitoring and numerical simulation results The error is about 8%,indicating that the research method is reasonable and feasible.The conclusions of the study can provide a basisand reference for accurately controlling the harmful effects of urban subway and shaft blasting.