EPB Tunnel Boring Machine

EPB (Earth Preasure Balance) Tunnel Boring Machine

EPB (Earth Pressure Balance) tunnel boring machines support the face with the pressure exerted by the earth inside the excavation chamber, which is evacuated by means of a variable speed auger to control the extraction of the material.

Tunnel boring machines initially designed for clayey soils, with the use of foams and polymers it has been possible to extend their field of action to other types of soils:

EPB TBMs use the excavation spoil located in the extraction chamber to maintain pressure on the face in order to avoid subsidence at the surface. The muck is transported to the shaft by conveyor belt or wagon.

The extraction of the material from the extraction chamber is carried out by means of an auger. By acting on the speed of the screw and on the force of the thrust cylinders, we can maintain a constant pressure on the face that allows the construction of a tunnel without affecting the surrounding surface infrastructure.