A cyclic p-y model for the whole-life response of piles in soft clay

• Published in: Computers and geotechnics Vol. 141; p. 104519
• Main Authors: White, D.J., Doherty, J.P., Guevara, M., Watson, P.G.
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01-01-2022; Elsevier BV
• Subjects: Clay; Conductors; Consolidation; Cyclic loading; Cyclic loads; Lateral loading; Materials fatigue; Model testing; Modelling; Piles; Soft clay; Soil mechanics; Soil strength; Stiffness; Lateral loading; Piles; Consolidation; Soft clay
• ISSN: 0266-352X; 1873-7633
• DOI: 10.1016/j.compgeo.2021.104519

It is evident from model testing, field studies and theoretical considerations that the strength of a soft clay can reduce and then recover – potentially to above the initial value – as a result of cyclic loading followed by consolidation. For piled foundations and well conductors, these changes in soil strength and the resulting lateral resistance affect their stiffness, capacity and fatigue. This paper introduces a new model for the cyclic lateral ‘p-y’ response of a pile in soft clay, using concepts from critical state soil mechanics, combined with a parallel Iwan model to capture the hysteric response. Example analyses show that the model can capture the general forms of behaviour observed in model tests, and is rapid and simple to implement. The model provides a new basis for whole life modelling of piles and well conductors, allowing changes in stiffness and capacity to be simulated, as well as improved modelling of fatigue accumulation. This approach allows more reliable design, quantifying the benefits and risks associated with evolving soil strength.