riven piles can be severely damaged during driving into soil with high boulder content and can potentially lose their structural integrity, resulting in pile refusal. This can consequently aggravate project cost, delays and environmental impact. Pile drivability assessments during the design stage are frequently carried out by designers or contractors, to ensure that the selected foundation system is suitable for the given soil conditions. Such assessments rely heavily on their expertise regarding specific soil conditions, pile properties and installation methods.

This procedure is often not documented in detail, which can cause disagreements with the client when significant pile refusal occurs. At the tender stage, the type of contract should identify the risk owner for piling design and installation; however, due to the complexity of the problem, the risk is not distinctly quantified and the risk ownerremain unclear for most projects. The urgency to optimize the design and minimize pile refusal in Sweden is evident, as more than 80 % of all the piles in 2021 were installed by impact driving. The intent of the presentation is to show the limitations and the effects of using the current assessment method, and how the research is currently aiming to develop new probabilistic methods. A transparent methodology to support the decision-making in pile design is in fact necessary for a cost-effective driving strategy and optimal design solutions. Results from geotechnical investigation are also discussed, in order to understand their potential contribution in a pile drivability assessment. This presentation is based on the research work of an ongoing PhD project supported by the Swedish Transport Administration through Better Interactions in Geotechnics (BIG) and by SBUF (Development Fund of the Swedish Construction Industry).