| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a concrete side ditch block bringing no play in low cost by using a form which does not require high accuracy. SOLUTION: A plurality of laterally protruded streaks 12 are parallelly formed in the upper half part of the curved side face 11 of a side ditch lid 1. A space is left in the longitudinal direction of the side ditch lid 1. A plurality of projections 13 are dotted in the lower half part of the curved side face 11. The weight of the side ditch lid 1 acts on the tips of the protruded streaks and the projections 13 and they are crushed and then, a collapse part 3 is formed. A coarse face is formed on the collapse part 3 and hence, friction is increased. The play between the lid and the side ditch is absorbed by the collapse part 3. The lid is closely attached to the side ditch. Even if an eccentric load acts thereon, the lid generates no play.
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