Soilmec's largest rotary rig, the R940, recently completed work in Zurich for Swiss foundation contractor Zschokke Locher.
The redevelopment of an industrial site into a residential complex required about 220, 1,200mm diameter, fully cased piles up to 32m deep. Work also included some 1,500mm diameter piles.
Ground conditions were extremely challenging, with 1m to 2.5m diameter boulders and a layer of very cohesive clay which made extracting casing difficult.
However, the machine was able to cope because it is fitted with a powerful rotary head developing 469kNm torque that can drive and extract casing.