Abstract:

According to the unfavorable geological problems, such as fault fracture zone, large deformation of soft surrounding rock, collapse, large slope, water and mud inrush, rock burst, high geothermal, etc., encounter during TBM boring in a tunnel, an open TBM with functions of electrohydraulic mixed jamming release, cutterhead enlargement cutting, shield extension, advance drilling rig, emergency drainage and air cooling device is designed; and functions of screw slag cleaner and steel arch frame jacking are added in practice. By cooperating with dam, advance grouting and pipe roof support, the TBM has successfully passed through the water gushing section with maximum water gushing capacity of 772.57 m3/h, rock burst section of 232 m, alteration section of 445 m, collapse section， and mud gushing section of 60 m. Finally, according to the practical experience, the shortcomings of the targeted design and the improving direction are put forward.

Key words: tunnel engineering, bad geology, open TBM