ABSTRACT
Offshore piled foundations are typically installed using an impact hammer. Increasingly, more attention is being given to use of vibratory hammers due to added benefits of prolonged pile life, reduced installation noise, and reduced risk of observing pile-run. This paper considers a case study in the North Sea, consisting of six positions where piles are installed in layered sands and clays. The Cone Penetration Test (CPT) data for the positions have been used in calculating the Soil Resistance to Vibratory Driving (SRV) as part of the Vibdrive method, from Holeyman (2002). This method has been compared with the SRV calculated using the non-CPT based β-method, from Jonker (1986). By varying the SRV used in driveability predictions, the results can be compared with the available driving records. It was found that the CPT based Vibdrive method consistently produced more representative results while still maintaining a conservative prediction.
