| 摘要 |
A method and apparatus for producing a bore hole lining from a number of pre-formed shells is described. The shells are assembled on a lower frame which is lowered into the bore hole by a predetermined distance in a series of steps, each step being of a length corresponding to the depth of each shell loaded, the frame being lowered after each shell is assembled thereon. The frame and batch of assembled shells so formed is then lowered to the lowest unlined portion of the bore hole. Grout is poured around the shells and allowed to set and the lower frame is detached from the batch and withdrawn. This method and apparatus allows relatively long bores to be lined.
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