Abstract
Bifurcation analysis considering variation of aspect ratio was carried out to investigate the influence of soil parameters on bifurcation behavior of normally consolidated cohesive soils under plane strain undrained compression loadings and its application to the prediction of slip surfaces. The soils exhibited plasticity indices of 10, 30, and 50.
The results indicate that bifurcation behavior of the soil with lowest plasticity index occurred at larger stress ratio and smaller axial strain than those with higher plasticity indices. Forms of slip surfaces can be predicted by distribution of maximum shear strain and stress states. We suggest that the soil with lowest plasticity index is brittle. In the case of the soils with higher plasticity indices, failure phenomena arrive from strain localization at slip surfaces through initiation and propagation of shear bands.
