Pipe jacking excavation method is done either mechanically, by hand or both. The manshield method is used when there are high uncertainties in the ground. The pipes are jacked into ground using powerful jacks driven by hydraulic power packs from the jacking shaft while the face of the tunnel is being excavated. The soils are usually removed on a chart and lifted out off the shaft by a crane.
Excavation by hand at tunnel face Jacking in the sleeve pipe Inside view of tunnel