Abstract:

West Qingling tunnel is constructed by TBM tunneling method assisted by drill and blast method. The stepping of TBM through the tunnel section constructed by drill and blast method is presented. The mode of stepping with arcshaped slide way and thrust cylinder and the mode of stepping with integral support frame and electrical motor drive are described in terms of technical features, key control points and operation methods. The two stepping modes are compared in terms of advantages and disadvantages. Finally， the mode of stepping with arcshaped slide way and thrust cylinder is chose.

Key words: West Qinling tunnel, TBM, arc shaped slide way, electrical motor drive, stepping technology