| 摘要 |
PROBLEM TO BE SOLVED: To provide a construction method for branching and meeting parts between a main line tunnel and a rampway capable of constructing branching and meeting parts between a main line tunnel to be constructed on, particularly, a large cross section and a rampway connecting this main line tunnel with the ground easily. SOLUTION: Branching and meeting parts of a main line tunnel and a rampway C of an outer shell part body A lining inner periphery of the main line tunnel B are constructed by a steel shell which digs and advances to construct the outer shell part body A of the main line tunnel B and lines inner periphery of a single body shield tunnel. Ground retaining walls D are constructed at a predetermined interval in the ground on its upper side, and its lower end part is supported by shearing keys protruding and provided in the outer shell part body A. Next, the ground between the ground retaining walls D and D is digged down to the outer shell part skeleton A. Then, the steel shell in the branching and meeting parts of the outer shell part body A with the rampway C is removed, and a body of the rampway C is constructed between the ground retaining walls D and D. |
