隧道开挖中楔形掏槽施工技术研究

Study of the Techniques for the Slotting Construction in Tunneling

楔形掏槽是斜眼掏槽中较易掌握的掏槽方式,其适用性较强,施工进尺较大,目前凡手持风钻进行爆破开挖的爆破作业,大多采用此方式。楔形掏槽工作方法在实践中有进一步创新,如采用大角度大抵抗线、加大掏槽高度、加大掏槽深度、加大单孔装药量、加大掏槽炮孔同段装药量等,但在应用时需根据地质情况合理加以选用,否则会影响围岩稳定性。介绍了楔形掏槽孔网参数及取值,进行了各种楔形掏槽创新方式的利弊分析,对正确使用楔形掏槽进行爆破作业有参考意义。

The wedge-shaped slotting method is one of the easily-mastered slotting approaches in the diagonally-slotting operation,which has wide applications and is quite efficient in drilling progress.Nowadays,most of the blasting or excavation operations performed with hand-held drills use this method,which is being further creatively improved in practice,for example,the adoption of great angles and great resistant lines,the increase of the slotting height and depth,the increase of the filling amount of explosive for each hole,the increase of the sizes of the holes and the filling amount of explosive for all the holes in the same section,etc.,which should be reasonably applied according to specific geological conditions,and the improper use of which may also result in the instability of the surrounding rock.The parameters of the hole nets,and the right choice of the parameters for wedge-shaped slots are introduced,with both the merits and demerits of each creatively new slotting method analyzed.It may serve as a useful reference for the correct use of the wedge-shaped slotting methods for blasting operations.