| 摘要 |
<p>PURPOSE:To safety and effectively dismantle an existing pipeline CONSTITUTION:An existing pipeline 100 is surrounded by sheaths 3, 6. The natural ground 200 outside of the existing pipeline 100 is excavated by a cutter 13, and the sheaths 3, 6 are advanced. A joint bolt of a segment l01a is removed by a core removing device 34. In the existing pipeline 100, a plurality of ring- form coupled blocks 71 of a covering rupture device 70 are separated from one another using a jack for pressing and protruded in the radial direction. All segments 101a and secondary coverings 102 situated the backmost are pressed and ruptured by these blocks 71 from their insides in a lump. The ruptured segments 101a and secondary coverings 102 are held from outside by a ring-shaped ruptured covering holding part 17. Accordingly the segments 101a and secondary coverings 102 can be ruptured as a large lump in the condition with falling prevented.</p> |
