| 摘要 |
PROBLEM TO BE SOLVED: To provide a tunnel construction device and a tunnel construction method capable of varying a tunnel section on the way without using an intermediate shaft. SOLUTION: This tunnel construction device constructs a small sectional tunnel T2 connecting to a large sectional tunnel T1. In that case, it is equipped with an erector 3 assembling a segment S with a large diameter in order to construct a large sectional tunnel T1 in a shield frame 1 of a shield boring machine 2 and, at the same time, assembling the segment S with a small diameter in order to construct a small sectional tunnel T2, a machine side cover member 22 provided to the rear end of the shield frame 1 in a detachable manner, removed in the case the large sectional tunnel T1 is constructed and mounted in order to close between the shield frame 1 and small sectional tunnel T2 in the case the small sectional tunnel T2 is constructed, and a tunnel side cover member 20 mounted to an opening section of the large sectional tunnel T1 in order to close a space between the large sectional tunnel T1 and small sectional tunnel T2 in the case it is switched from the large sectional tunnel T1 to the small sectional tunnel T2. |
