Grout holes with W80, Malmö City Tunnel, Sweden
The construction of the railway tunnel under the City of Malmö in southern Sweden involves drilling of grout holes for ground water screening. The grout holes are drilled in three steps with a final distance between the holes of 1,25 meter. Casing is pushed into the ground to a depth of 11-12 meter with a pile driver. Wassara W80 is then used for drilling the actual hole to a depth of 17-22 meter.
The high groundwater level, 2-3 meter under the surface, and the requirement to avoid damage to the road bed led to the choice of Wassara.
Main contractor: NCC
Sub-contractor: Hercules Grundläggning (Foundation).
The Wassara drilling went well. No damage to the road bed occurred neither was any drilling problem encountered due to the high ground water. The time required to drill one hole was 12-15 minutes.