To provide a structure for a drain pipe capable of adjusting an amount of drainage accurately and easily and excellent in drainage efficiency.SOLUTION: There is provided a structure for a drain pipe 1 to be installed on a water surface or under the water surface of a water storage region, with an exhaust port 14 formed on a side face 12 of the drain pipe 1. There are two forms of the structure: a door plate opening type and an exhaust port movable type. The door plate opening type drain pipe 1 is configured so that a door plate 15 provided on the exhaust port 14 is brought into sliding contact with a pipe inner surface, and the door plate 15 is slid to adjust a release area 16 of the exhaust port 14, thereby adjusting an amount of drainage. The exhaust port movable type drain pipe 1 is configured so that a side surface 12 in a constant range including the exhaust port 14 serves as an independent movable part 13 and is coupled to a pipe part on an upstream side and/or downstream side, and the movable part 13 is rotatable in a circumferential direction of the side surface 12 to relative the pipe part on upstream side and/or downstream side. Such a rotation operation is performed to change a vertical position of the exhaust port 14, adjusting the amount of drainage.SELECTED DRAWING: Figure 4【課題】排水量の調節が正確かつ容易であって、排水効率に優れた排水パイプの構造を提供する。【解決手段】貯水域の水面又は水面下に配置する排水パイプ１の構造において、排水パイプ１の側面１２に排水口１４が形成されていることを特徴とする。扉板開閉式と排水口可動式の２形態があり、前記扉板開閉式の排水パイプ１は、排水口１４に付設された扉板１５はパイプ内側面に摺接し、扉板１５を摺動させ排水口１４の解放面積１６の調節を行うことにより排水量の調節を行う。 排水口可動式の排水パイプ１は、パイプの、排水口１４を含む一定の範囲の側面１２が独立した可動部分１３として、上流側又は／及び下流側のパイプ部分に連結され、可動部分１３は前記上流側又は／及び下流側のパイプ部分に対して側面１２の周方向に回動可能であって、該回動操作を行い排水口１４の上下位置を変化させ、排水量の調節を行う。【選択図】図４
