J. Pestana, A. Whittle, A. Gens
The undrained response of cohesive soils is of paramount importance in geomechanics and it has beenmodelled extensively for the last 50 years. In comparison, drained behaviour of clays has received onlymodest attention. Drained and undrained behaviour is signi¿cantly affected by past consolidation stresshistory. This paper evaluates the capabilities of the MIT-S1 effective stress model, described in acompanion paper, for predicting the anisotropic stress–strain–strength behaviour of clays. The paperillustrates the selection of model parameters for Lower Cromer Till, using data from standard types oflaboratory tests. Comparison of model simulations with measured response for Lower Cromer Till andBoston Blue Clay illustrate model capabilities. The work focuses initially on comparisons of modelpredictions with measurements from undrained triaxial and plane strain tests on initially K0-consolidatedspecimens. Comparisons with measured data from undrained shear tests performed in different modes ofshearing for LCT and BBC show that the model: (a) gives excellent predictions of maximum shear stressconditions and accurately describes the non-linear shear stress–strain behaviour; (b) accurately describesthe anisotropic shear stress–strain–strength conditions for different consolidation stress histories; and(c) gives realistic description of mobilized friction angles, especially at large OCR’s. The paper then focuseson the effects of consolidation stress history for isotropically consolidated specimens of resedimentedLower Cromer Till and Boston Blue Clay. Finally, the paper compares model predictions for drained sheartests on K0and isotropically consolidated specimens with overconsolidation ratios, OCR410; used toevaluate particular aspects of the critical state framework of soil behaviour. Overall, the model givesexcellent predictions of the effect of initial anisotropy and overconsolidation stress history on the shearstress–strain and volumetric behaviour of clays.
Published on 01/01/2002
DOI: 10.1002/nag.238Licence: CC BY-NC-SA license
Views 1Recommendations 0
Are you one of the authors of this document?