| 摘要 |
The invention relates to a method of forming a cavity in the casting of preferably parallel earth walls, said method comprising embedding and use of a sleeve which comprises an essentially tubular male part and an essentially tubular female part, wherein the outer wall of the male part has outer threads which are in engagement with corresponding inner threads of the female part, and wherein mutual rotation of the male part and the female part causes the male part to be displaced relatively to the female part. New aspects are inter alia that the male part and/or the female part comprises a means intended for breaking through the surface of the earth walls for forming an engagement with it, said means being rotated so as to saw a ring-shaped hole in the earth wall. The invention moreover relates to a sleeve which is suitable for embedding in concrete, and which is essentially tubular and has a variable length. The ends of the sleeve are provided with means for engagement with the preferably parallel earth walls formed for the casting, said means being intended for braking through the surface of the earth wall for arrangement of the means at a certain depth in the earth wall. |
