Using free fall penetrometer measurements to identify near surface soil types and quantify geotechnical properties

Geotechnical site characterisation of near surface seabed is crucial for pipelines, cables, and mudmat foundations. Instrumented Free Fall Sphere (IFFS) provide a cost-effective means of rapid data acquisition in the seabed's uppermost layers, and thereby mitigate uncertainties arising from spatial variability. An existing interpretation framework has been developed for fine-grained soils, which uses the acceleration data to quantify strength profile. However, this approach does not distinguish between soils with similar strengths but with different permeabilities. To address this knowledge gap, a next-generation IFFSu was developed by adding pore pressure transducers(PPTs) to monitor pressures both during and after free-fall penetration.