Whole-Life Geotechnical Design: What Is It? What's It For? So What? And What Next?-Paper

Paper

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Whole-life geotechnical design assesses a structure using the actions and soil resistance present at each stage of its life, rather than pairing the largest expected load with a single conservative minimum resistance. Earlier loading can change seabed strength, stiffness and geometry through consolidation, cyclic hardening or softening, sediment movement and scour, affecting the response to later events.<br /><br />The paper focuses on consolidation in soft clay. Loading and subsequent dissipation of pore pressure can strengthen soil and increase foundation resistance; repeated loading and consolidation can also alter stiffness and cause settlement. Critical-state-based models, supported by finite-element analyses and centrifuge tests, can represent these evolving responses and help predict performance over time.<br /><br />Applications include fixed and sliding subsea foundations, pipelines, piles and conductors. Examples show that accounting for consolidation can substantially reduce required foundation size—by around half in some cases—and that a tolerably mobile foundation may be smaller still. Whole-life analysis can also predict accumulated settlement, changing operational capacity and potentially high retrieval loads at decommissioning. More broadly, it can inform fatigue assessment, asset monitoring, reuse, life extension and end-of-life decisions, and can support a geotechnical digital twin.<br /><br />Routine adoption will require better site-characterization methods for measuring soil changes over repeated loading and drainage, fuller histories of design actions, accessible and validated analysis methods, field or model-test evidence, and explicit guidance in standards. The central conclusion is that tracking how actions and ground conditions evolve can produce more realistic and efficient designs while improving lifecycle safety and management.

Keywords

whole-life geotechnical design

consolidation

soft clay

seabed strength

pore pressure dissipation

foundation resistance

cyclic loading

settlement

subsea foundations

critical-state models