Modelling pile driving in chalk and calcarenite soils using a hybrid continuous-discontinuous method

PhD student

Fei Liu

Supervisors

Prof Yinghui Tian	Dr Shubhrajit Maitra	Dr Hongyuan Liu University of Tasmania	Dr Tingfa Liu University of Bristol

Project Start Date: March 2024

Project Details

Offshore piles have become more than 80% of the offshore wind power foundation market due to their ease of installation and low cost. The wide distribution of chalk and calcarenite soil has made them the focus of recent pile performance studies. Compared to traditional soils and rocks, the strength of this type of soft rock varies considerably during pile driving. In addition, current common design codes have been shown to provide very limited guidance for driving large diameter piles in such weak rocks and/or very hard soils. In particular, the problem of extrusion around the pile ends requires more rigorous investigation. A better understanding of pile driving in soft rock has the potential to significantly optimize pile design and reduce installation risk and cost.

This project aims to model pile driving in such soils by using a hybrid continuous-discontinuous method that combines the advantages of state-of-the-art continuous methods (i.e. finite element method) with the most advanced discontinuous method (i.e. discrete element method) to address the challenge of transition from continuum to discontinuity through fracture and fragmentation.