| 摘要 |
<p>PURPOSE:To withdraw existing pipes buried in the ground one by one without breaking them. CONSTITUTION:Tension is given to a guide pipe 4 passing through an existing pipe 3, and a driving pipe 20 is driven forward in the ground by a driving device 14 to take the existing pipe 3 thereinto. A pushing and drawing pipe 22 of the driving device 14 is moved along the peripheral surface of the guide pipe 4. A driving pipe holding device 30 provided to the pushing and drawing pipe 22 is brought into contact with the inside surface of the driving pipe, and a driving direction of the driving pipe 20 is controlled. When the driving pipe holding device 30 is brought into contact with the inside of the existing pipe 3 to retreat the driving device 14, the existing pipe 3 can be drawn inward together with the pushing and drawing pipe 22.</p> |
