| 摘要 |
<p>PCT No. PCT/FI81/00035 Sec. 371 Date Jan. 20, 1982 Sec. 102(e) Date Oct. 20, 1982 PCT Filed May 21, 1981 PCT Pub. No. WO81/03354 PCT Pub. Date Nov. 26, 1981.A procedure for creating a vertical drain by pushing into the ground an insertion tube (7) housing within itself a so-called prefabricated drain (9), by pulling out the insertion tube and cutting off the prefabricated drain. The prefabricated drain is cut off with a cross-cutting means located within the insertion tube (7) at such height, or in such a layer as for instance a sand stratum (3) which accepts the water conveyed by the prefabricated drain.</p> |
