Enel Greenpower’s 140MW Oyster Bay Windfarm, located in the Eastern Cape province in South Africa.
The project
Foundation piling for 4 no. Wind Turbine Bases comprising of 96 no. continuous flight auger piles up to 24m deep, at the Oyster Bay Wind Farm Project, situated along the South Coast of South Africa.
The challenge
The drilling of CFA piles to a depth of up to 24m required the use of a powerful BG28 piling rig in CFA mode.
The design required the installation of full length steel cages that were slender and prone to buckling, requiring additional stiffening reinforcement for lifting and placing into position.
Severe weather conditions were another obstacle, in the form of strong winds and rain.
The solution
The design was provided by the client and required various quality control measures to confirm the parameters used. These included integrity testing, cross-hole sonic logging and pile compression/tension tests.
The foundation works involved the installation of 96 no. 750mm diameter CFA Piles to varying depths. This method provided a fast and economical piling solution ideal for unstable soil conditions.