Method and apparatus for replacement of pipelines

摘要

A method and apparatus for replacement of an existing non-frangible pipeline includes creating open access to opposite ends of an pipeline and threading a cable having a wedge mounted thereon through the pipeline so that the wedge is positioned proximate one of the ends of the pipeline. The wedge is pulled through the pipeline from the other end of the pipeline so that the wedge slits the pipeline to form a slit pipe in a borehole. The slit pipe is removed from the borehole and a rear end portion of the slit pipe is attached to a front end portion of the replacement pipe . As the slit pipe is pulled out of the borehole, the replacement pipe is drawn into the borehole. The boring apparatus has a braided cable and a boring head having an expander sleeve and a lengthwise bore of sufficient diameter so that the cable can pass therethrough. An insert is disposed inside a loosened, enlarged diameter portion of the braided cable so that braids of the cable are wound about the insert, forming a stop portion of the cable having a diameter insufficient to pass through the bore of the boring head, so that the boring head can be towed through the ground by the cable with stop portion of the cable in contact with a rear portion of the boring head. The boring heads have cutting edges in a variety of sizes and the boring heads can be interchangeably mounted on the cable and the stop. The pulling machine has a portable pulling device with an elongated stake configured for insertion into the ground, a winch including the pulling cable and a fixture for mounting the winch so that the winch can operate to exert a horizontal pulling force with the cable and is secured against movement when the lower end portion of the stake is inserted into the ground.