高地应力互层软岩隧道爆破控制技术研究

Research on Blasting Control Technology of Interbedded Soft Rock Tunnel with High Crustal Stress

西部山岭隧道施工中,经常需要采用爆破施工作业,而爆破施工也是隧道变形控制的重要环节。为得到高地应力作用下互层软岩隧道爆破施工参数,以甘肃尖山隧道互层软岩段为工程背景,在采用光面爆破的基础上,考虑炮孔直径和炮眼间距两种水平因素,通过改变周边眼的炮眼直径和炮眼间距,分析了五种施工工况下爆破模拟过程,与原隧道设计轮廓进行对比分析平均线性超挖值和最大线性超挖值。结果表明:光面爆破可以更好地控制超欠挖,且本工程中当炮眼直径在40~42mm,炮眼间距在38~40 mm时,对互层软岩隧道的超欠挖控制有较好的效果,可在隧道后期的施工中,更好地控制隧道的变形。

In the construction of western mountain tunnels, blasting construction is often required, and it is also an important part of tunnel deformation control. In order to obtain the blasting construction parameters of the interbedded soft rock tunnel under the action of high crustal stress, taking the interbedded soft rock section of Jianshan tunnel in Gansu province as the engineering background, two horizontal factors of the head hole diameter and the blasthole spacing are considered on the basis of smooth blasting, the blasting simulation process under five kinds of construction conditions is analyzed by changing the blasthole diameter and blasthole spacing of the surrounding holes, and the average linear overbreak value and the maximum linear overbreak value are compared and analyzed with the original tunnel design contour. The results show that: smooth blasting can better control the over-under-excavated value. In this project, when the blasthole diameter is 40~42 mm and the blasthole spacing is 38~40 mm, the over-under-excavated value of the interbedded soft rock tunnel can be better controlled, and the deformation of the tunnel can be better controlled in the later construction of the tunnel.