Modelling high-velocity pile uplift in saturated sand in laboratory tests
Modelling high-velocity pile uplift in saturated sand in laboratory tests
Dynamic tensile loading frequently affects piles in offshore environments, where rapid loading conditions, such as vibrodriving, facilitate suction at the pile tip. While soil deformation beneath the pile tip during vibratory driving has been investigated using particle image velocimetry (PIV), this method cannot directly resolve cavity formation during rapid uplift, which therefore remains insufficiently understood. This study presents a laboratory test setup that enables the investigation of high-velocity pile uplift in fully saturated sand. Three representative upward motions are selected based on field tests and approximated to define a simplified laboratory input signal. The field tests use a model vibrodriver and are evaluated to characterise pile uplift motion during vibratory driving. The laboratory test stand enables extraction tests on model piles at velocities up to 3 m/s to reproduce the three representative upward strokes. The experimental setup includes sensors to measure the extraction force and the total and pore pressures directly beneath the pile tip. Results demonstrate laboratory reproduction of the upward motions observed in the field and show that rapid extraction reduces the pressure beneath the pile tip below hydrostatic equilibrium, while tensile force increases with extraction acceleration and velocity. The proposed approach provides a controlled basis for further laboratory-scale studies to better understand processes at the pile tip during vibratory driving and their implications for pile resistance.
Mechthild Cramer
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Session 6: Onshore and offshore foundation systems
https://doi.org/10.53243/ICPMG2026-169