Simulation of Offshore Piling Using Advanced Dynamic Material Point Method (MPM)-Paper

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The paper investigates offshore pile installation using the Convected Particle Domain Interpolation (CPDI) method, an advanced form of the Material Point Method (MPM) designed to handle the large soil deformations that can undermine conventional finite-element simulations. CPDI represents material points as deforming domains, reducing numerical oscillations as particles cross the computational grid.<br /><br />The formulation is validated against analytical and experimental results for strip-footing bearing capacity and sand-column collapse. It is then applied to a two-dimensional axisymmetric pile-driving model. Sand behavior is represented with a hypoplastic constitutive model that includes small-strain stiffness, while pile–soil contact is handled using a penalty method. A simplified two-phase formulation is used to model saturated sand by accounting for hydrostatic and excess pore pressures.<br /><br />For dry sand, CPDI predicts pile penetration broadly comparable to an ABAQUS simulation, although the results differ because the models use different numerical approaches and dimensions. Under the reported hammering conditions, the pile reaches 3.3 m in dry sand and 4.7 m in saturated sand after 20 blows. Increased pore pressure in saturated soil reduces effective stress and interparticle friction, lowering resistance to penetration.<br /><br />The authors conclude that CPDI is promising for simulating pile driving and studying soil behavior during installation. However, the simplified saturated-soil model may not capture highly dynamic behavior or liquefaction reliably, and numerical oscillations can occur at low stress levels. Future work could use a multi-velocity two-phase formulation and improved constitutive models.

Keywords

CPDI

Material Point Method

offshore pile installation

pile driving

hypoplastic constitutive model

sand behavior

saturated sand

pore pressure

soil deformation

pile-soil contact