2D-plot of relative density versus settlements for back analysis of applied stress [kN/m²] by FEA for a circular plate (d = 0.32 m).

The diagram applies to subsoil conditions of Rhine sand. According to the deformation characteristics illustrated at the top right corner of the diagram, blue curves apply to the flexible loading characteristics of the elephant's foot, and the green curve ( = 350 kN/m² loading step 5) applies to rigid loading characteristics used in the FEA model. The relationship is detailed in the text. The range of stresses that can be back-calculated from in situ conditions of relative density of subsoil (0.3 and 0.47) and measured values of s (20.28 mm, 21.16 mm, and 26.32 mm) is marked by a box.