| 摘要 |
PURPOSE:To save the cost of construction as well as prevent the occurrence of damage and incident by a method in which a riverside pit is provided at the upper part of revetment and a pipe through which air is supplied to or discharged from a bag, a water level detector tube for dam, a dewfall remover for the bag, etc., are provided inside the pit. CONSTITUTION:When a rising and falling dam 4 is raised, air sucked up by a strainer 11 provided to the main pipe 8 through which air is supplied or discharged is supplied into a bag 5 from an upper air supply and discharge port 19 through a rotary blower, a overpressure preventive safety valve 13, a check valve 14, an air supply valve 15, and a check valve 22 provided in a riverside pit 18 by means of a motor 10 in an operation chamber 9. And, the air is also supplied into the bag 5 from a lower air supply and discharge port 21 connected to a lower drain pipe 20 through s branch pipe 8c and an air-water separation cyclone 23. When reaching a design water level, the float 32 of a detector tube 31 goes up to actuate an automatic falling pilot valve 33, and thereby a discharge valve 17 is opened to discharge air inside the bag 5 through an air discharge pipe 8a to the outside. Thus, the bag 5 is fallen down. |
