VERFAHREN ZUM ZIEHEN VON AUSSENGESTAENGEN.

摘要

In a method of boring out and pulling double tubing (9, 10) having inner and outer tubing, the boring-out and pulling of the tubing being effected by means of at least one power-driven rotary head (25, 26) traversable on a drill carriage (6), an installed ground anchor is loosened by virtue of the fact that the inner tubing (9) is pulled and the anchor installed before the outer tubing (10) is pulled, that the installed anchor is then secured against pulling-out by inner tubing (9) or a supporting element, and that, when the anchor is secured, the outer tubing (10) is pulled over the inner tubing (9) or the supporting element and that both the inner and outer tubing are deposited together. IMAGE