| 摘要 |
PCT No. PCT/DE95/01658 Sec. 371 Date Oct. 8, 1997 Sec. 102(e) Date Oct. 8, 1997 PCT Filed Nov. 20, 1995 PCT Pub. No. WO96/24794 PCT Pub. Date Aug. 15, 1996Disclosed is a method of extracting a hollow member laid in the earth, e.g. a lead pipe, which is accessible at both its open ends. For this purpose a hose which may be internally pressurized, is introduced in an unpressurized condition into the pipe, the hose is then internally pressurized, pressing the hose against the internal wall of the pipe, and then, maintaining the internal pressure, the pipe is extracted from the earth in its longitudinal direction by means of the hose without axial movement between these two. In this way rupture of the lead pipe during extraction is avoided. Behind the rear end of the lead pipe in the direction of extraction, a new pipe can be coupled to the hose or to the lead pipe to be extracted, and which is introduced into the earth simultaneously with extraction of the lead pipe. An additional traction element can be introduced together with the hose into the pipe, which is pressed against the inner wall of the pipe by the hose which is internally pressurized, and which is used either alone or in conjunction with the hose to extract the pipe. |
