Pipe eating uses a microtunneling type machine to crush and “excavate” the existing pipe together with sufficient surrounding ground to accommodate the new pipe which is simultaneously jacked in behind. The interior volume of the existing pipe can be grouted to provide a more uniform face condition for excavation and to prevent the loss of excavation fluids, or slurry seals added in front of the cutting head. The steering mechanisms for the machine can be used to control the line and grade of the new pipe.
Description published by the International Society for Trenchless Technology.