The dead water device null a which is used for the revised manner and its revised manner of artesian ground directly under the existing

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently improving the ground on a foundation slab concrete by sealing underground water right under the foundation slab concrete to prevent the water from being discharged. ;SOLUTION: A lower water seal member S, which can be closed by sliding and moving a shutter plate 2 supported by a support plate 1, is set on a toundation 12 of an existing structure on the ground 14, in which underground water is confined. And an upper water seal member P, in which a plurality of water seal rubber packings 3 having therein an insertion hole 4 having a smaller diameter than the diameter (w) of an excavation pipe 1 are stacked through washers 5 in a case 6, is set on the member S. And the pipe 7 is inserted into the hole 4 and in the watertight conditions sealed with the packings 3, a through hole 15 is formed in the foundation 12 by means of the pipe 7 and after excavating the ground 14, injection agent is injected into the hole 15 to improve the ground as far as the foundation 12. The pipe 7 is lifted and the plate 2 is moved by sliding it to close the through hole 15.;COPYRIGHT: (C)1998,JPO