光面爆破在阿克塔格山输水隧洞软弱围岩中的应用

Application of smooth blasting in weak surrounding rock excavation for the Aketage Mountain water conveyance tunnel

在软弱围岩中实现光面爆破,主要是通过选择正确的光爆参数及合理的支护来实现的.阿克塔格山输水隧洞因开挖面积较小,施工中基本采用全断面光面爆破开挖方法,这有效地减少了隧洞超欠挖,使出渣、回填混凝土工作量均相应减少.该隧洞施工遵循新奥法施工原理,根据围岩的自稳能力,一次支护紧跟掌子面,使围岩变形量得到有效的控制,充分发挥了围岩自身的承载能力及其自身的支护作用,其效果良好.

Smooth blasting in weak surrounding rock excavation has relied largely upon properly selected blasting parameters and rational excavation method.Because of small size of excavated sections,the tunneling has been carried out using the full section excavation method.This permits efficient reduction of the volume of over break and under excavation,as well as that of removed spoil and backfilled concrete.The tunneling follows the principle of the New Austrian Method taking into account the self-stability capacity of surrounding rock with its primary support immediately behind of the working space.The surrounding rock has a controlled deformation to be able to efficiently make the most of its self-bearing and self-supporting capacities.