Evaluation of pile driveability predictions in sand

Pile driveability is a critical component of pile design process to ensure that the selected impact hammer has sufficient energy to drive piles to final depth, without refusal, and acceptable fatigue damage during driving. Pile driving records often show considerable scatter because of variations in soil conditions and behaviour, pile dimensions, and set up during interruptions in driving. However, representative pile drivability prediction remains a challenge. Over the past decade, Seaway7 have installed numerous foundations for offshore wind turbine generators. Recent Seaway7 experience in North Sea revealed that pile driveability predictions still have room for improvement installation feasibility. This paper considers pile driving records from different offshore campaigns in North Sea to cover a range of subsea applications including varying pile properties, impact hammers, geographical locations, and sandy soil conditions. Driving records have been backanalysed with as-installed blow count and hammer energies to assess the offset of existing in-house prediction model.