| 摘要 |
An arrangement for establishing an underground passage includes a first line of consecutive pipe sections which are pressed through the ground in a path which deviates from the desired course of the passage whenever the first line of pipe sections encounters an obstruction. A second line of the consecutive pipe sections follows the trailing end of first line, and a planing tool support carrying at least one planing tool is interposed between the trailing end of the first line and the leading end of the second line of consecutive pipe sections. The planing tool extends transversely beyond the planing tool support and removes the excess material between the actual path and the desired course, and the removed excess material is deposited between the previous path and the second line of consecutive pipe sections and cemented therein by the introduction of a cementing material into such deposited excess material. The pipe sections from the leading end of the first line can be removed and transported to the trailing end of the second line to be added thereto as the two lines are advanced. The planing tool support is coaxially mounted at the trailing end of the first line, and anti-friction bearings may be interposed between the planing tool support and the leading end of the second line. At least one cylinder-and-piston unit may extend between the planing tool support and the leading end of the second line.
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