At LKAB:s crushing plant in Svappavaara, Sweden, a thickening plant is under construction. In order to reinforce the ground for the sedimentation basin, two large foundations are being constructed.
The foundation needs to withstand stress from tension load, therefore steel piles are being anchored to the bedrock, some 6-7 meter below surface and 8 meter into bedorck. Casing in the dimension 193 mm (6”) were set all the way down to bedrock. As the drilling took place very close to the crushing plant itself, no pressurizing of the ground could be allowed.
Mikael Creutz, Foundation Engineer at the consulting company Golder Associates, recommended water-powered drilling as it was considered the only feasible drilling technology. A total of 135 m (455 ft.) was drilled in this highly sensitive environment.