Numerical modeling of pullout tests in an extremely soft, sensitive, and thixotropic clay

Resumo

Three usual challenges related to numerical modeling of geotechnical problems are addressed in this
paper - large distortions of finite element meshes, the soil-structure interface, and calibration of soft clay
parameters. The objective of this paper is to obtain a reliable numerical model to reproduce experimental results
and perform parametric analysis. The paper presents the approaches and techniques adopted to numerically
simulate pullout tests of mini piles submitted to large displacements in extremely soft, sensitive, and thixotropic
clay. A two-dimensional finite element model was assumed, considering the axisymmetric condition, to simulate
the fluid coupled analysis in Abaqus/CAE software, taking into account two conditions: saturated clay and
pullout undrained loading. Considerations and conclusions on the mobilization mechanisms of the total pullout
force, base resistance and shaft resistance, and the influence of the parameters were presented and discussed. The
validity of the approaches and techniques used was highlighted by the good agreement between the numerical
and experimental results. The quality of the parametric results corroborates the conclusion that the numerical
model is reliable and the software is a powerful tool to analyze complex interface problems related to piles
embedded in very soft clay.