| 摘要 |
PROBLEM TO BE SOLVED: To improve work easiness by omitting carrying-out labor, by separately carrying in a driving machine and an earth retaining plate, when digging down a tail part, when laying a concrete box body having the height larger than that of another box body arranged side by side the concrete box body. SOLUTION: When a waterway such as a closed conduit is composed of a concrete box body 4 continuously embedded in a plurality of vertical rows and a concrete box body 12 arranged at a proper interval between these concrete box bodies 4 and having a downward projecting part having the height larger than the concrete box body 4, a push-in jack 13 is arranged inside a side plate 1a of the tail part 1c of an open shield machine 1, and an earth retaining sheet pile 14 is connected to a lower part of this push-in jack 13. The push-in jack 13 is extended downward, and the earth retaining sheet pile 14 is pushed in the ground under the side plate 1a, and earth of the side is retained. The concrete box body 12 having the large height is arranged by excavating the inside of the earth retaining sheet pile 14 in this state. COPYRIGHT: (C)2006,JPO&NCIPI
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