An implicit nodal integration-based three-dimensional particle finite element model for simulating dynamic saturated porous media

Abstract

Large deformation analysis of dynamic saturated porous media holds significant importance in accurately describing the life of various geotechnical and geological applications, since they can seamlessly capture the continuous variation of geomaterials with extreme changes in configurations and properties. Many numerical models have been developed, while most of them are limited to two-dimensional scenarios and explicit time integration schemes, which therefore compromise their accuracy and efficiency in studying low- and medium-frequency practical problems. In addition, different stabilisation techniques with tunable parameters are often required when using the efficient linear elements for dynamic analysis. To overcome these hurdles, this work introduces an implicit three-dimensional nodal integration-based particle finite element method (N-PFEM) that combines the advantages of a mixed variational principle, a nodal-based strain smoothing technique, mathematical programming, and the particle finite element method, ensuring the accuracy and robustness in analysing dynamic saturated media. The three-dimensional N-PFEM is thoroughly examined against four numerical benchmarks, for which numerical solutions agree well with reference solutions or experimental data. The model is further applied to simulate earthquake-induced slope failures, which characterises the effect of material property on the initiation and propagation of landslides in a three-dimensional space. The developed model holds important implications for developing numerical approaches and demonstrates strong potential as an effective and practical tool in analysing the hydro-mechanical behaviour of geomaterials in real applications.