| 摘要 |
The present invention relates to a vertical drain construction method for riprap layers, aiming to create excavation holes using a perforation device and fill the holes with sand or soil in installing a vertical drain in flimsy grounds with a riprap layer, thereby letting the inserted vertical drain remain in a more stable status. The method for constructing a vertical drain in flimsy grounds with a riprap layer according to the present invention includes a perforation step (ST 1) in which the perforation process is conducted using a perforation device with a rock-digging bit on its lower part to penetrate the riprap layer while a casing is inserted along with the rock-digging bit; a filler filling step (ST 2) in which the perforation holes are filled with sand or soil; a casing drawing step (ST 3) in which the casing, which was inserted in the perforation step, gets pulled out when the sand or soil filling is done; and a vertical drain inserting step (ST 4) in which a vertical drain is inserted in the sand or soil using a drain type device. [Reference numerals] (AA) Perforation hole; (BB) Sand filling; (CC) Casing drawing; (DD) Vertical drain inserting |
