STRAIGHT FORWARD DRILLING Ground stabilization by jet grouting columns using LKAB Wassara Single pass jet grouting at Bergendahl Foods, Skåne, Sweden May-July 2013

Bergendahl Foods

Ground stabilization by jet grouting Bergendahl Foods in Skåne is expanding their storage capacity by construction of a new 32 m high automated storage building in Skåne For the first time in Sweden, it was realized with the LKAB Wassara Single-pass Jet grouting hammer Two of the lines of jet grouted columns

Ground stabilization by jet grouting Warehouse floor: 100 cm thick concrete basement… …lying on 288 columns Columns with OD 800 mm/ average depth 5,5 m Floor must withstand a load of 10 800 tons

Shortening the production time Average production capacity was 15-20 installed columns per day, or… …~ 20-30 min per hole, i. e., ~ 7-8 min for the drilling down and ~ 14-15 m for the grouting-up sequence Drilling ROP (down): 1 m/min Jet grouting ROP (up): 2 m/min “The realization of this project would have been close to impossible without the water-powered jet grouting hammer from LKAB Wassara and in addition estimated production time savings was about a factor 2-3”, says Drilling Manager Fredrik Toresson and Site Manager Dag Karlsson at PEAB.

Shortening the production time The pattern of 288 holes of 153 mm was drilled and jet grouted during a period of two months with an average production time of 15-18 installed columns per day Traditional operations would – if possible – have doubled (at least) the production time Column center distance 3 m

Difficult geological conditions Sand - friction soil - sand - rock The downward drilling stopped once reaching 30-40 cm down into homogenouos rock (nozzle just below top of the rock ) LKAB Wassara Single-pass jet grouting system – an indispensable tool Reasons for choosing the technology from LKAB Wassara: - Requirements of having no settlements Excavated and pressure tested column of OD 800 mm

Next steps On-going tenders for jet grouting projects in: Växjö, also ground stabilization Bergen, temporary impermeable walls Together with PEAB: Elaboration of an cost model for the LKAB Wassara part of the project

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