Verfahren zum Ermitteln der Reichweite eines Hochgeschwindigkeitserosionsverfahrens in einem Baugrund

摘要

A ground boring equipment has a vertical lance (12) pushed into the ground and rotated while an erosion fluid is pumped through the lance and out of radial jets (14). Hollow pipes (18,20) are inserted into the ground at a set spacing from the lance to monitor the reaction force from the jets ie. to determine when the jets have eroded the required diameter. The pipes are slit, or have inlet apertures to monitor the height of the fluid in the pipes and/or the reaction force.