Construction manner null of shielded tunnelling machine and

摘要

PROBLEM TO BE SOLVED: To establish an outer shell preceding type shield tunnel construction method in which the shell part is in advance excavated in a ring form and a lining is provided in this part for supporting the earth pressure and water pressure from the natural ground reasonably, whereby it is possible to effectively erect the lining and make use of the excavated section. SOLUTION: This shield excavating machine concerned is composed of an outer steel shell 1 and an inner steel shell 2, wherein the outer shell 1 is furnished on the whole periphery with a mildly curved surface in convex form over the whole circumference while the inner shell 2 is positioned confronting the outer with a prescribed spacing reserved in between and has a curved surface 5 swelling inward in four places. In this part, working shaft is formed, and segments carried in therefrom are assembled along the inner surface of the outer shell 1 so that a lining is formed having a mildly curved surface convex outward. Segment(s) for the working shaft is attached to the inside of this lining in the zone with the working shaft and removed along with excavation of the inside of the lining.