长短孔爆破控制超欠挖技术研究

Technology Study on Controlling Over-excavation and Under-excavation by Blasting Long and Short Holes Alternately

针对目前地质复杂、大断面隧道钻爆法施工中超欠挖问题引起的工期延误、成本增加、安全质量问题,结合既有传统爆破技术,在隧道施工中提出隧道爆破炮孔长短孔结合技术、周边眼精确定位技术,分析总结出软弱围岩、中硬岩、硬岩在周边眼的钻孔最佳角度选择,长短孔搭接长度及装药方式,减少了隧道施工中由爆破引起的超欠挖问题,节约了成本,确保了工程质量,对隧道同类工程的施工具有指导意义。

In the paper,aimed at the problems of project delay,cost increase and safety quality caused by over-excavation and under-excavation from the drilling and blasting construction of complex geology and large-section tunnel,the combination technology of long and short holes in tunnel blasting and precise positioning technology of peripheral holes are proposed in tunnel construction in combination with the existing traditional blasting technology.And then,it is concluded that the best drilling angle choice was made about soft surrounding rock,medium hard rock and hard rock in peripheral holes as well as overlapping length of long and short holes and charging method,which could reduce the problem of over-excavation and under-excavation caused by blasting in tunnel construction,save costs and ensure the engineering quality.It is of guiding significance for the construction of similar tunnel engineering.