Thoughts on residual strength of lateritic soils

摘要

The present work shows the results of ring shear tests performed on some Brazilian lateritic soils. The clay content of these soils is greater than 50%. However the peak and residual friction angles are close. Such behavior is probably due to the aggregate structure of the clay, caused by the laterization process. This aggregate structure begins to collapse after a vertical stress of about 900 kPa is applied in an oedometric test, in dry state. It was observed that the behavior of lateritic soils and pure clays are very different when considering the classical correlations between grain size and shear strength.