Using hardening soil model for describing the behavior of varied density sandunder the load

The authors analyze the Hardening Soil Model possibilities for describing the soil behavior under the load, using numerical simulation of the stabilometric tests for varied density sand.According to the study, the assumption that dilatancy angle stays constant is correct only for the dense soil. On the other hand, for the loose or medium density soil this assumption is unacceptable. For the loose and medium density sands, the calculation error in volumetric strain analysis may exceed 50 %.In order to assess the adequacy of soil behavior description in the calculations using the model of "Hardening Soil" numerical simulations were performed using Plaxis triaxial testing of soil. In deviatoric loading the loose soil consolidants, the dilatancy development in the sand of average density has an alternating pattern, the dense sand deconsolodates. The values parameters of the model "Hardening Soil" were determined by the results of experimental data obtained in the AO «NIIES» in triaxial tests the «Liuberetskii» sand and on the recommendations of the program Plaxis. As the results of numerical studies, the soil model "Hardening Soil" describes quite well the development of volumetric strain with the full compressing the soil and the development of shear deformations in the deviatoric loading.In the case of deviatoric loading the relationship between the centerline and the volume deformation is essentially non-linear (Fig. 3a), in contrast to the theoretical assumption of constancy of the angle of dilatancy. In the dense sand at the approach to the limiting value the increment of volume strain (by absolute value) increases, and in the loose sand decreases