| 摘要 |
A method according to the invention for installing an underground pipe uses a ground piercing tool having an elongated tubular tool body, a striker disposed for reciprocation within an internal chamber of the body to impart impacts to an impact surface for driving the tool forwardly through the ground, and an expander having a diameter greater than that of the tool body. The method includes the steps of securing a tubular shroud to the expander so that the ground piercing tool is disposed inside of the shroud, operating the tool in forward mode over a run so that the impact tool and shroud move forward, fitting a front end of a replacement pipe into sliding engagement with a rear end of the shroud, and pushing the replacement pipe from a rear end portion thereof in a manner sufficient to insure that a front end of the replacement pipe remains in sliding contact with the shroud as the tool moves forward.
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