As we saw it before, It is the way of pushing pipes in the ground with an hydraulic station pressure. The excavation of the ground is done by either way or manually, or mechanically we are talking in this case of micro-tunneling. This method is usually used for the bigger network diameter that is to say for a diameter upper than 1000.

ADVANTAGES:

• Less expensive.
• Direct contact with the ground, that allow a complet awarness of the unknow and the how we progress.
• reactivity of the technic.

INCONVENIENTS:

• Difficult to use for diameters below 1000.       

 PRECONISATIONS:

• For dry and wet networks, under gravity or under pression.
• Concrete, sandstone, steel, melting and PRV pipes.