城区隧道电子雷管起爆错相减震机理分析

Mechanism analysis of fault-phase vibration reduction for tunnel blasting initiated by electronic detonators in city area

降低爆破振动是城市隧道爆破的关键技术问题,采用时-频分析方法对隧道爆破振动的一般特征进行了分析,结果表明:爆破地震波是多列爆炸波叠加的结果,采用毫秒延期电雷管起爆时,由于雷管段数的限制,起爆网络经常被分成几个时段,对爆炸波的叠加方式缺乏控制,往往出现若干个振速峰值。通过工程试验,研究了采用电子雷管起爆时的减震效果,结果显示采用电子雷管起爆时,如果技术措施合理,能使爆破振动速度峰值显著降低。根据电子雷管起爆延时精度高的特点,并借鉴干扰减震的思想,提出并讨论了错相减震机理。实际城市隧道爆破工程应用反映了错相减震爆破设计达到了理想的减震效果。

Reducing vibration is a key problem for tunnel blasting in city area. Here, a time-frequency analysis was performed to analyze general features of tunnel blasting vibration. The results showed that the blasting seismic wave is formed with multiple-series blast waves superposition; the initiation network is often divided into several sections at millisecond delay blasting due to limiting of the detonator number, and the superposition manners of blast wave show a lack of control, so the waveform always has several peak vibration velocities. The vibration mitigation effect was studied with engineering tests during initiation with electronic detonators. If the reasonable technical measures were adopted, the blasting vibration peak velocities decreased significantly. Moreover, the mechanism of fault-phase vibration reduction was proposed and discussed by means of high precision of delay initiation of electronic detonators and by using the thought of blasting vibration reduction induced by waveform interference for a reference. The engineering application of tunnel blasting in urban area showed that the blasting design with fault-phase vibration reduction has an ideal effect on vibration reduction.