In situ undrained shear strength characterization using data from free fall ball penetrometer tests

摘要

Large-deformation finite element analyses (FEAs) employing coupled Eulerian-Lagrangian technique are performed to simulate penetration of a spherical free fall penetrometer (FFP) in clay. FEA results are analyzed following the principle of energy conservation. Although final depth of penetration d(p), varies with penetrometer mass, diameter and impact velocity, bearing capacity factor at depth d(p) is a unique function of d(p) normalized with penetrometer diameter. A simple methodology is proposed for predicting in situ undrained shear strength profile using FFP test data. Shear strength values predicted using the proposed methodology are in excellent agreement with instrumented test data reported in literature.