| 摘要 |
PROBLEM TO BE SOLVED: To provide an intermediate pushing device capable of preventing a seal from being crushed due to soil load and enhancing water cut-off performance of the seal. SOLUTION: This intermediate pushing device 5 is arranged halfway among a plurality of steel shells 4 arranged between an excavator for excavating the natural ground and a base pushing device arranged at the start of a vertical shaft. The intermediate pushing device includes: a front wall 6 connected with a rear end of the steel shell 4 in the front; a rear wall 7 connected with a front end of the steel shell 4 in the rear; a front part outer cylinder 8 mounted on the front wall 6; a rear part outer cylinder 9 mounted on the rear wall 7 and overlapped on the front part outer cylinder 8 across a clearance A; a front part inner cylinder 10 mounted on the front wall 6; a rear part inner cylinder 11 mounted on the rear wall 7 and overlapped on the front part inner cylinder 10 across a clearance B, the seal 28 blocking the clearance B; and an intermediate pushing jack 12 bringing the front wall 6 and the rear wall 7 closer to each other or separating them from each other. Soil load is received by the front part outer cylinder 8 and the rear part outer cylinder 9 to prevent soil load from being applied on the front part inner cylinder 10 and the rear part inner cylinder 11 and prevent the seal 28 from being crushed. COPYRIGHT: (C)2011,JPO&INPIT |
