Abstract:

The application of mucking through muckdropping boreholes in the sinking of the vertical shafts on the branch of No. 6 line of Chongqing Metro is analyzed. Conclusions drawn are as follows: 1) Mucking through muckdropping boreholes can accelerate the shaft sinking and reduce the shaft sinking cost when the vertical shafts are deep, have large crosssection and have underground galleries stretching from the shaft bottoms toward the ground surface; 2) It is rapid, safe and reliable to drill muckdropping boreholes by rotary drilling rigs.

Key words: vertical shaft, muckdropping borehole, mucking, rotary drilling rig