Improved Formulation of the Hardening Soil Model in the Context of Modeling the Undrained Behavior of Cohesive Soils

Abstract

The analysis of an important drawback of the well known Hardening Soil model (HSM) is the main purpose of this paper. A special emphasis is put on modifying the HSM to enable an appropriate prediction of the undrained shear strength using a nonzero dilatancy angle. In this light, the paper demonstrates an advanced numerical finite element modeling addressed to practical geotechnical problems. The main focus is put on serviceability limit state analysis of a twin-tunnel excavation in London clay. The two-phase formulation for partially saturated medium, after Aubry and Ozanam, is used to describe interaction between soil skeleton and pore water pressure.

On consistent nonlinear analysis of soil–structure interaction problems

“…It has also some certain drawbacks such as unlimited shear strength for soils exhibiting dilatant behaviour in shear, but also ' 3 σ based stress dependency in definitions of the initial and the unloading-reloading stiffness moduli. Problems with the unlimited shear strength appear at larger strains, which is not the case in the considered class of problems, unless the global ultimate limit state (ULS) is analysed; however, this problem can easily be removed by coupling the shear and volumetric mechanisms in the model, as shown by Truty and Obrzud [9]. The second aforementioned model deficiency is important in the case of cohesionless soils, where ' p , the stiffness stress dependency, represents soil behaviour in a definitely more accurate manner.…”

Influence of bedding and backfill soil type on deformation of buried sewage pipeline

“…Calculations were performed using the finite element commercial software ZSoil,[ [7], especially intended for performing numerical analyses in geotechnics. [ [8,9]. Plain strain and elastic-perfectly plastic constitutive model of soil were assumed in the considered case.…”

Selected aspects of designing deep excavations

“…14),  effective friction angle for two clay layers was assumed  = 30 and  = 32, respectively, where as effective cohesion was assumed equal to c = 0 kPa,  no dilatancy has been assumed for cohesive material following the discussion in Truty and Obrzud [18], a) b) Fig. 12.…”