Geotechnical properties of residual soils from the North-east of Argentina

North-east Argentina is almost completely covered by residual soils, as well as southeast Paraguay and central and southern Brazil. These residual soils arise as the result of the weathering of basalt. This article present certain mechanical, physical and chemical properties of residual soils from Obera, Misiones, in north-east Argentina based upon tests on specimen from 71 boreholes. Changes in the mineralogical, physical and geomechanical characteristics with depth are related to different degrees of weathering. The correlations between different soil properties are presented and analysed and mean and coefficient of variation of the most significant soil properties is discussed and compared with results reported for similar soils from different places. The results indicate that the studied residual soils have physical, mineralogical and mechanical properties that are highly dependent on the level of alteration. Variability of soil properties increases at higher levels of degradation and chemical alteration.