METHOD AND APPARATUS OF EXCA-VATING VERTICAL TUNNEL

摘要

A large diameter vertical tunnel can be excavated efficiently, with excavating earth and sand gathered and discharged easily. A large diameter casing (75) is pressed in the ground by the unidirectional rotation or reciprocating rotation or these combination. The holder and bucket (45) excavator is placed in the ground. Opening the cap (45) and lowering backet (27), the front of the cap digs into earth and sand. And with the cap closed, earth and sand is gathered into the bucket.