GUIDED PIPE JACKING

The technology allows to build gravity sewerage by means of a trenchless technique.  The installation of sewerage vitrified clay pipes in parts of up to 60 meters (from an entry to a receiving chamber),  in depth of up to 6 meters and with a provided inclination is carried out in three basic stages:

 

Stage I – The pilot hole

 

To enter this stage, it is necessary to prepare an entry and a receiving chamber  first. Then a machine is founded at a predetermined ordinate, with a particular inclination and finally, a machine is set in a horizontal position. Afterwards, the regular drilling stage follows. Depending on geological conditions, the first rod gets an ordinary or a widia  ‘pilot’ on. The following pilot rods, screwed with each other are driven one by one into the ground, making a pilot string until it appears in the receiving chamber.  During this stage, all  the direction swerves are immediately observed by a rig’s operator and corrected by means of a pilot movement.  The exact direction of a pilot’s way is marked by means of optical instruments system and a theodolite. All the parameters are transmitted by cameras system and shown on a screen. Such a system guarantees a very precise drilling, with all the parameters provided, and the inclination – with an unfailing precision.  
 

Stage II - Reaming and casing pipes jacking

 

This stage is about  enlarging the existing hole and pushing steel casing pipes in. The reaming is done by means of a head which is suitable for the ground conditions. The borings which appear are carried outside by means of revolving feeding screws. As the progress is made, the following pipes and feeding screws are added and in the receiving chamber the rods are pushed out.

 

 

Stage III - Installing of vitrified clay pipes in and pushing casing pipes out

 

During the third stage, steel casing pipes (in the diameter which is suitable for product pipes)  are replaced by the final vitrified clay pipes.