Capturing strain localization in reinforced soils

Abstract

Lade's single hardening soil model with Cosserat rotation embodied in the finite element method is employed to investigate the behavior of geosynthetic reinforced soils with special attention to the development of shear banding. The ability of the finite element model to detect shear banding in a reinforced soil is examined against three high quality small-scale laboratory plane strain tests on Toyoura sand with and without reinforcement. These three tests were chosen because of the clear failure surfaces that developed in the soil during loading. The FEM analyses were able to reasonably simulate the plane strain laboratory tests including both unreinforced and reinforced cases. The FEM analyses gave reasonably good agreement with the experimental results in terms of global stress-strain relationships and shear band occurrences. Furthermore, and based on FE analyses of a hypothetical geosynthetic reinforced soil (GRS) retaining wall, it is shown that the geosynthetic reinforcements are very effective in hindering the formation of shear bands in GRS retaining walls when small spacing between the reinforcement layers was used. When used properly, the geosynthetic reinforcements made the soil behave as a truly reinforced mass of considerable stiffness and strength.

Effects of periodic fluctuations of micro‐polar boundary conditions on shear localizations in granular soil–structure interaction

“…It is widely accepted that post‐bifurcation behavior can be well captured by micro‐polar (Cosserat) continuum models as a powerful way to eliminate the limitations of classical continuum in problems involving shear localization. Among the works, in which the Cosserat continuum models were used as the regularization approach in order to analyze shear strain localization problems, are contributions of Mühlhaus 57, De Borst 42, Tejchman and Wu 58, Tejchman 59, Steinmann 60, Ehlers and Volk 61, Gudehus and Nübel 62, Manzari 63, Li and Tang 64, Khoei et al 65, Alsaleh et al 66, Alshibli et al 67, Arslan and Sture 68, 69, Kitsabunnarat et al 70, Khoei and Karimi 71, Alsaleh et al 72 who adopted a micro‐polar elasto‐plastic approach, and by Tejchman 55, Bauer and Tejchman 73, Tejchman and Bauer 74, Bauer and Huang 75, Tejchman and Gudehus 76, Bauer and Huang 77, Huang et al 78, Maier 79, 80, Tejchman and Bauer 81, Bauer et al 82 who adopted a micro‐polar hypoplastic approach.…”

Reinforced Soil Wall Analysis under Working Stress Conditions Using a Two Phase Model with the Introduction of a New Design Parameter

“…De Buhan and Sudret [2], Sudret and De Buhan [3], Hassen and De Buhan [4], and De Buhan et al [22] simulated rockbolted tunnels and piled-raft foundations using two phase approach and perfect bonding hypothesis. Ling et al [23], Kitsabunnarat et al [24], Zarnani et al [25], and Yang et al [26] assumed perfect bonding in discrete modeling of reinforced soil structures under static and seismic loading. All the mentioned researchers concluded that the assumption of perfect bonding between the soil and inclusions in reinforced soil structure analyses has a very minor effect on the results.…”

Nonlinear Dynamic Analysis of Railway Wagon End Wall under the Action of Granular Media

“…The key issues to consider are the nonlinear constitutive relation of the granular media, the simulation of contact relationship between granular media and end wall, and the simulation of the boundary condition to set up the finite element model of the end wall. We define the height ratio of the granular media = / , by introducing the theory of finite element modeling of the retaining wall structure; we considered the special contact relationship (e.g., see [14][15][16][17][18][19][20][21][22]) between granular media and continuum and set up finite element models with different ; the FEM model is shown in Figure 8. Deformation of granular media relates to current stress state and loading process because granular media are anisotropic material and do not follow Hook's law.…”