SANISAND-MPL: Toward a Unified Framework for Offshore Soil Behavior under Undrained Loading
SANISAND-MPL: Toward a Unified Framework for Offshore Soil Behavior under Undrained Loading
Offshore foundations are increasingly deployed in regions with highly variable soil conditions and are subjected to complex environmental and seismic loading. Depending on the soil's hydraulic conductivity and loading characteristics, the response can span fully drained, partially drained, and undrained regimes. To advance a unified framework for simulating offshore soil behaviour, this study introduces SANISAND-MPL, a constitutive model designed to capture state-sensitive liquefaction response with enhanced volumetric plastic flow. The new model enables realistic representation of both medium and dense sand behaviours, encompassing flow liquefaction and cyclic mobility mechanisms, thereby satisfactorily simulating the pre- to post-liquefaction responses. In this extended abstract, an undrained cyclic triaxial test on medium-dense Karlsruhe fine sand specimen was simulated to assess the models ability to reproduce key responses. The analysis highlights the critical role of the plastic flow rule in simulating excess pore water pressure generation, critical state slopes in triaxial extension and compression, and shear strain accumulation. Results show that incorporating realistic cyclic dilatancy and contraction behaviour enables SANISAND-MPL to accurately capture both the onset of liquefaction and its subsequent effects across a range of relative densities.
Junyu Zhou; Merita Tafili; Amin Barari; Nazanin Irani; T. Wichtmann; Lars Bo Ibsen
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Special Session 5: Combination of numerical and physical modelling
https://doi.org/10.53243/ICPMG2026-304