Result shows that drainage effectiveness of upwardhole has an obvious advantage over that of plumb hole.
结果表明，仰孔的排水效果明显优于铅孔。
2
The paper mainly introduced the construction method for anchor cable with large-angle upwardhole in tailrace surge tank.
介绍了尾水调压室大角度上仰孔锚索的施工方法。
3
The destroy of the roof produced by stress wave of upwardhole side blasting is less than that of the level hole blasting. The work of prizing flexible rock decreased by 58. 3%.