| 摘要 |
PURPOSE:To quickly and easily perform laying operations of a covering sheet by a method in which plural ropes are laid at an adequate interval between dams facing each other, a covering sheet is sent from the top end to the inside of the dams, and the ropes are loosened to lay the sheet on the bottom. CONSTITUTION:Plural piles 3a and 3b are driven at an adequate interval in dams 2a and 2b facing each other, and ropes 4 with pulleys 6 are laid between the piles 3a and 3b. A covering sheet 7 is sent from the top end 2c onto the ropes 4, long sheets 8 are joined in order, and both ends 7a and 7b of the sheet 7 are folded upwards. At the same time, ropes 11 are connected to beams 9 provided to the tip end 7c of the sheet 7, and the sheet 7 is pulled by a dragger 12 through the ropes 11 and laid. The ropes 4 are then loosened, the sheet 7 is landed on the bottom 5, and both ends 7a and 7b of the sheet 7 are extended and fixed to the top ends 2a and 2b. |
