| 摘要 |
PROBLEM TO BE SOLVED: To realize smooth transfer of a box culvert by preventing rotation of itself in a horizontal direction on a sliding surface at the time of sliding on the sliding surface while supporting the box culvert. SOLUTION: This jack 2 is slidably placed on the sliding surface 1 disposed in the inner bottom of a guide ditch 4 extended in the depth direction in an open ditch (or culvert) A, and it supports the box culvert 3 disposed in the upper part of the guide ditch 4 from below when elongated. It is provided with a housing 6 that slides on the sliding surface 1. Furthermore, it is provided with a lifting/lowering mechanism 7 disposed approximately in the central part of this housing 6 to lift/lower the box culvert 3 when it is expanded or contracted, and a traverse mechanism disposed on the side of the housing 6 to control the position of the housing 6 relative to a rising part 4a in the guide ditch 4 when it is operated. COPYRIGHT: (C)2006,JPO&NCIPI
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