Analysis of the influence of suction on shear strength

Abstract

The Barcelona Basic Model, BBM, is one of the most used elasto-plastic models for unsaturated soils. A briefly presentation of the BBM is made and some aspects are discussed. Its mathematical formulation is summarily presented and the influence that some parameters have on the model is evaluated. Some limitations, such as the stress state variables, the hysteretic hydraulic behaviour, the shear strength increase with suction, the soil collapse and the strain-softening are succinctly discussed. At the end, the evolution of shear strength along suction reduction paths, associated to collapse phenomenon, is analyzed. In some suction reduction paths, softening type behaviour is observed.