Physical modelling to explore foundation response to soil strength changes – within and beyond the laboratory and at different scales

1. Home
2. Publications
3. Online Library
4. Physical modelling to explore foundation response to soil strength changes – within and beyond the laboratory and at different scales

There is growing recognition of the importance and benefit in accounting for the changes in soil strength that occur over the design life of a structure. Such strength changes occur because of the competing effects of strain softening and consolidation hardening. Beneficial effects of consolidation-induced hardening are recognised in some areas of offshore geotechnical design. For instance, the remoulding of the soil that takes place at the pile wall interface during installation (either by driving or with the assistance of suction) recovers with time, and this setup effect of axial pile capacity is typically allowed for in design. Other examples where consolidation-induced improvements in foundation capacity are allowed for in offshore design include the increase in bearing capacity of shallow foundations due to consolidation under their self-weight, and drag anchor capacity increase between installation and hook-up. This paper provides examples from physical modelling that explore the response of foundations to both reductions in soil strength, which is beneficial for foundation installation as it lowers the risk of installation refusal, and increases in soil strength, which improves foundation capacity over the design life. Each example links the (changing) strength mobilised by the foundation to the changes in soil strength that can be measured in different types of penetrometer tests. Additionally, and in recognition of the more muted strain softening response of reconstituted soils to that of natural soils, this paper also extends beyond physical modelling in the laboratory to include reduced scale modelling in the field providing an example of how this step-out in scale and to a natural soil adds value to the initial physical modelling performed in a centrifuge, ultimately facilitating a more rapid take-up of the research outcomes in practice.

4th Asia-Pacific Conference on Physical Modelling in Geotechnics (ACPMG2024)

Keynotes