Numerical Simulation of Layered Compressible Soils’ Creep Deformation Under Monopile Foundation

Creep deformation, a key issue in foundation stability, is a long-term soil deformation that can cause significant damage and catastrophic failure to various structures. This numerical investigation aims to estimate the creep deformation variation of layered compressible soils under monopile foundation using the PLAXIS 3D analysis software. Accordingly, three-layered compressible soils are considered, and software input layer properties are computed from laboratory tests. Numerical analysis is focused on the influence of soil layer profile, pile embedment length, diameter, and loading on creep deformation. A total of eight models are developed to capture the 3D creep deformation behavior of layered soils under pile loading. Results of numerical simulation indicated that creep deformation behavior is significantly affected by influencing variables. The arrangement of the compressible soil layer, placing CH at the bottom, indicated a drastic increase in creep deformation, providing 230% more deformation with an extreme rate of the creep-to-time curve than MH and ML soils. Creep deformation increases with decreasing pile embedment length and diameter, and vice versa. The analysis also revealed that a small change in loading induces a large magnitude of deformation. A 25% increase in load induced a 240% increase in creep deformation, which revealed that creep is very sensitive to loading. In conclusion, the findings offer practical implications for geotechnical design perspective, showing how layered soil profiles, pile geometry, and loading impact the long-term stability and functionality through creep deformation of pile foundations.