The changing strength of soft soil around subsea infrastructure

This PhD thesis studies the changing strength of soft fine-grained soils in response to cyclic loading and consolidation in order to advance current design practise. A standout feature of the research are experimental data, obtained mainly from geotechnical centrifuge experiments, that consistently demonstrate significant soil strength increases following both low and high level cyclic loading, due to dissipation of excess pore pressure. Results from the centrifuge tests formed the basis for developing a new effective-stress framework, using critical state soil mechanics, that quantifies changes in soil strength considering the balance between undrained cyclic loading and consolidation.