Associated and non-associated visco-plasticity and plasticity in soil mechanics

Abstract

The visco-plastic model is established as a realistic general description of soil behaviour as well as a computationally convenient fiction for solving any properly formulated plasticity problem. The Paper focuses attention on simple elastic-ideally plastic formulations in which both associated and non-associated forms of behaviour are assumed. In the non-associated form the usual bounding theorems are not applicable and it is of interest that in some cases collapse situations significantly different from those given by limit theorems are predicted. Also, some problems of strain-dependent plasticity are solved to demonstrate the flexibility of the viscoplastic algorithm. Le modèle viscoplastique constitue une description générale et réaliste du comportement du sol aussi bien qu'un modèle facilement calculable pour résoudre tout problème de plasticité convenablement formulé. L'étude concentre l'attention sur des schémas (ou modèles) où les deux types de comportement (élasticité simple et plasticité idéale) sont pris en compte simultanément ou séparément. Dans les schémas (ou modèles) où les deux types de comportement ne sent pas associés, les théorèmes limites ordinaires ne sont pas applicables et il est intéressant de noter que dans certains cas on prévoit des situations de rupture très différentes de celles données par les théorèmes limites. Il y a également quelques problèmes de déformation plastique qui sent résolus afin de démontrer la flexibilité de l'algorithme visco-plastique.

Bearing Capacity Evaluation of Footing on a Layered‐Soil using ABAQUS

“…in Terzaghi's equation soil is assumed to be perfectly plastic while in current finite element analysis soil is an elasto-plastic material. The results found in the current study are in good agreement with the results achieved by other researchers in the past [12] [13]. It should be noted in this section the dilation angel is assumed to be 4° which is equal to ϕ-34° [14].…”

Non-Associated Plasticity for Soils, Concrete and Rock

“…The fact that even limit loads may depend on the dilatancy characteristics of the granular material is known, but has as yet hardly been demonstrated by examples. Davis (1968) presented an example of compression between rough platens, and this example was also used by Zienkiewicz et al (1975). New examples are given here.…”

High-Order FEM Formulation for 3-D Slope Instability

“…where, [19], and is further extended to achieve the safety factor for the slope instability assessment by different researchers (e.g., [20][21][22][23][24][25]). In this technique, an application of gravity loading is followed by a systematic reduction in soil strength until failure occurs, which is achieved using a strength reduction factor (SRF), to the frictional and cohesive components of strength in the form of factored frictional f  and cohesive compo- …”