| 摘要 |
PROBLEM TO BE SOLVED: To provide a shield excavation and assembly simultaneous construction method which enables shortening of a construction period and reduction in cost spent for a propelling jack.SOLUTION: A length 2L of a segment assembly part between the front end of a tail seal and the furthest receding position of a shield jack is made to be twice a width L of a segment, and each stroke of the shield jack is made to have at least two or more lengths. The minimum stroke is set to "(the width of the segment)+(a K-segment insertion margin)+(an assembly allowance)" or more and the maximum stroke is set to "2×(the width of the segment)+(the assembly allowance)", and a second hydraulic circuit 50B is provided which divides the shield jack into one or plural groups, hydraulically controls, makes the position of a target point of application of force which is a resultant force point of respective propulsive forces arbitrarily controllable, and expands and contracts each shield jack during excavation. A segment assembly is started as soon as a space allowing the segment assembly to be performed is formed between the furthest receding position of a shield jack and an existing segment, and the segment assembly of one ring is completed during excavation. |
