| 摘要 |
PROBLEM TO BE SOLVED: To provide a river fish protecting artificial reef that are made of concrete and can release the flow velocity of the river, as the production cost and the installation cost are saved, further can prevent the protecting artificial reefs from moving or falling. SOLUTION: In the river fish protecting artificial reefs 1 that comprises a concrete block 11 having an inner space 112 and holes 12 having a diameter so that fishes can pass there through from individual outer faces 111 into the inside of the concrete block, the concrete block 11 has a profile of regular hexahedral shape, not connected to the inner space 112, and has a flowing through-hole 13 through which fish can pass is bored from one side of the outer face 111 to the other wherein the entering holes 12 are bored on the outer face 111 of individual tetragonal blocks, and the entering hole 12 and the flow-through hole 13 has the same positional relashionship, thus all of the reefs can take the same standing position even if they are set so that any outer face 111 of the tetragonal block is positioned at the bottom face of the river. COPYRIGHT: (C)2007,JPO&INPIT
|
