| 摘要 |
PURPOSE:To enable compact stacking of constituent members in transporting by mutually and symmetrically raising both sidewall parts of a main block from both sides of a bottom plate in a tilting manner to the outside at a prescribed angle and providing both engaging parts formed on both ends of the main block with a shape of point symmetry relatively to the central point of the bottom plate part. CONSTITUTION:Sidewall parts (2b) mutually and symmetrically rising in a tilting manner at a prescribed angle are formed in both sides of a bottom plate part (2a) in a main block 2. Since the afore-mentioned bed has the above- mentioned cross-sectional shape, gaps between the adjacent main blocks 2 are extremely small even in mutually stacking the main blocks 2 and can be compactly stacked to effectively utilize a loading space, such as a truck. Hole parts 9 for water drainage ports are formed from the outside in the bottom plate part (2a) leaving thin layers and filling members 10 are engaged with the hole parts 9. Thereby, operation to form the water drainage ports in field assembling can be readily performed simply by operation to remove the filling members 10 and cut the left thin layers with a cutter, etc. |
