发耳高瓦斯公路隧道开挖爆破技术

贵州水盘高速公路发耳隧道为煤与瓦斯突出隧道,高瓦斯工区瓦斯涌出量大,施工必须采取爆破开挖。通过总结非电(导爆管)爆破与电雷管爆破的区别,分析导爆管爆破和电雷管爆破在大断面隧道爆破中的适用性。依据发耳隧道现场爆破实践,从隧道成形、超/欠挖现象、堆碴抛投情况、循环周期和安全系数等方面对比高段别毫秒导管爆破和煤矿许用毫秒延期电雷管爆破的效果。结果表明:高段别毫秒导爆管爆破方式明显优越于煤矿许用毫秒延期电雷管爆破方式。为大断面隧道爆破开挖提供了理论参考,对提高施工安全以及取得较好的社会效益和经济效益有所裨益。

Excavation Blasting Technologies for Fa’er Highway Tunnel with High Gas Concentration

Fa’er tunnel on Shuicheng Panxian highway is a tunnel with coal and gas outburst risk. Blasting excavation has to be carried out in the tunnel section, where there is serious gas emission. In the paper, the difference between Nonel blasting and electric detonator blasting is summarized, and the applicability of Nonel blasting and electric detonator blasting in large cross section tunnel are analyzed. Comparison and contrast is made between the blasting effect of millisecond delay electric detonator and that of high stage millisecond Nonel in terms of tunnel shape, overbreak/shortbreak, mucks, cycling time and safety coefficient, with the blasting excavation of Fa’er tunnel as an example. The results show that the high stage millisecond Nonel blasting is superior to the millisecond delay electric detonator blasting. The paper can provide theoretical reference for blasting excavation of other large cross section tunnels in the future.