Influence of the kinematic testing conditions on the mechanical response of a sand

The influence of the laboratory testing conditions on the mechanical characterization of a compacted sand is investigated on the basis of standard triaxial and of plane strain compression tests. The two sets of experimental results lead to the independent calibration of two constitutive models. In fact, while the triaxial tests suggest a perfectly plastic behaviour for the sand, the plane strain results show marked strain softening effects, in particular for the denser samples or for high values of the confining pressure. The perfectly plastic and the strain softening models are then applied to the stability analysis of a cantilever sheet pile. The numerical results enable the drawing of some conclusions on the effect that the material model, chosen and calibrated on the basis of a particular laboratory test, could have on the predicted performance of geotechnical structures.