| 摘要 |
<p>PURPOSE:To perform the inspection, replenishment and compaction of a sand foundation under a safe environment by projecting an overhang section including a space opened vertically into the upper half section of the rear section of a frame. CONSTITUTION:A messel shield machine is furnished with a front frame 10 and a tail frame 20 which are high in stiffness, and is also equipped with an intermediate jack 30 connecting both of the frames 10 and 20 together. The tail frame 20 is provided with a hanging section 21 and an overhang section 22 projected backward above the hanging section 21. A sand foundation 50 is lined up onto an existing pipe 40 located down below the overhang section 22, the sand foundation 50 is concurrently filled up over the circumferentail surface of the existing pipe. In the second place, both of the frames 10 and 20 are moved with jacks 31 and 32 contracted. When the tail frame 20 is advanced, a cavity is formed in a place where a vertical post 26 has passed. As a result, a part of the sand foundation 52 flows in the cavity, so that the sand foundation 50 is lowered. In this case, the sand foundation 50 is replenished while a work space within the overhang section 20 is being utilized. A space is formed behind the overhang section 22 with both of the frames 10 and 20 advanced, and the space is thereby filled with back filled soil 60.</p> |
