Analysis of the shear strength of expansive clays

The swell of an expansive soil is always accompanied by a substantial reduction of its shear strength. The results of a large laboratory experimental research are taken as a basis to analyse the shear strenght of compacted soils subjected to different physico-chemical conditions. A comparison is made between the swell characteristics measured in a consolidometer on one hand and the shear strength given by a sing shear apparatus on the other hand. We show an important influence of the physico-chemical conditions on the swell behaviour as well as on the shear behaviour of the soils analyzed. We propose some interesting phenomenological relations between swell and shear behaviours of expansive clays.