A simple hypoplastic model for normally consolidated clay

Abstract

The paper presents a simple constitutive model for normally consolidated clay. A mathematical formulation, using a single tensor-valued function to define the incrementally nonlinear stress-strain relation, is proposed based on the basic concept of hypoplasticity. The structure of the tensor-valued function is determined in the light of the response envelope. Particular attention is paid towards incorporating the critical state and to the capability for capturing undrained behaviour of clayey soils. With five material parameters that can be determined easily from isotropic consolidation and triaxial compression tests, the model is shown to provide good predictions for the response of normally consolidated clay along various stress paths, including drained true triaxial tests and undrained shear tests.

Improvement of a hypoplastic model to predict clay behaviour under undrained conditions

“…As outlined by Niemunis [12] and recently by Huang et al [5], one of the limitations of Eq. (1) is that at normally consolidated and slightly overconsolidated states the hypoplastic models do not perform correctly in predicting the behaviour under undrained conditions.…”

“…Niemunis [12] and Huang et al [5] proposed modifications of hypoplastic models to overcome this shortcoming, which are similar from the conceptual point of view. In both cases the tensor L is made bi-linear in D such that…”

“…The model by Huang et al [5] has been developed with the particular aim to predict the behaviour of normally consolidated fine-grained soils. The model is characterised by five soil parameters equivalent to parameters of the model by Mašín [7], and in comparison with this model a clear improvement in predictions under undrained conditions and equivalent and acceptable predictions of drained behaviour have been demonstrated.…”

Influence of initial density of cohesionless soil on evolution of passive earth pressure

“…To increase the application range, hypoplastic constitutive models were extended by an elastic strain range [32] and inherent anisotropy [5,49,51]. Furthermore, particular hypoplastic models were developed for cohesive fine grained materials [7], for soils with low friction angles [21] and for modeling the mechanical behavior of clays [24,28]. For the present numerical investigations of strain localization in a cohesionless sand a hypoplastic model based on a micro-polar continuum is used.…”

Modeling of bearing capacity of footings on sand within stochastic micro‐polar hypoplasticity

“…The hypoplastic models have been extended to increase the application range, small strain [23], anisotropy [24] and viscosity [25][26][27]. It can be also used for soils with low friction angles [28] and clays [29][30][31][32].…”