TUNNEL EXCAVATOR

摘要

PROBLEM TO BE SOLVED: To perform excellent lining by a method wherein primary covering is effected such that forms are assembled and concrete is placed in the forms right after excavation at which slackening of an excavated ground does not occur. SOLUTION: A form device 5 for primary covering to effect cast in place concrete lining is movably disposed at the part right preceded by a cutter drive device 14 at the front of a push pipe 3 arranged along the axial direction of an excavator. By extending a form progress and regress jack 24A arranged at a ring frame 23 of the form device 5. A form member 25A is securely pressed against the inner surface of a tunnel. Concrete is placed and cured and in this case, a ring frame 23 is separated away from the push pipe 3. This constitution relieves the generation of vibration of the form member.