Modeling wheel-induced rutting in soils: Indentation

The analysis of indentation of rigid cylindrical wheels into frictional/cohesive soils is presented. Three- and two-dimensional numerical simulations were performed using the finite element code ABAQUS to assess the influence of soil strength parameters, dilatancy, and wheel geometry on the relationship between the indentation force and wheel sinkage. The effect of three-dimensionality in the indentation process is studied in detail. Three-dimensional effects were found to be minor for clays though significant for sands. An approximate analytic approach is also presented, which relates indentation force and wheel sinkage for given wheel geometry and material parameters. Theoretical results are compared with preliminary experimental data obtained from small-scale indentation tests, and satisfactory qualitative agreement is shown. The results described in the paper are regarded as reference for numerical and analytic modeling of wheel rolling, to be presented in a separate paper.