| 摘要 |
PROBLEM TO BE SOLVED: To form a widening machine in a simple structure, to improve construction work efficiency for widening, to shorten a construction period, to reduce construction cost, to enable widening of a large cross section, to enhance the degree of freedom and stability of a skeleton structure, and to form a segment in a lightweight structure. SOLUTION: This tunnel widening construction method constructs a pre-lining there by excavating the outer periphery of a widening part in a slit shape by its front boring advancing cutter 6 simultaneously with boring advancing of a shield machine after being reversed by overhanging the widening machine 3 from a body part 2 of the shield machine 1 by excavating the natural ground by rotary cutters 4 and 5 by overhanging its side surface. COPYRIGHT: (C)2007,JPO&INPIT |
