Geotechnical Characterization of an Unsaturated Soil in the Barreiras Formation, Pernambuco — Brazil

This paper presents a geotechnical characterization of an unsaturated soil from the "Barreiras Formation", in Pernambuco state, Brazil. The investigated area encompasses a slope under erosive process located in the forest reservation of Horto de Dois Irmão, in Recife. The purpose of the study was to elaborate an executive project for the recuperation of the eroded area. The geotechnical investigation program presented, borehole with Standard Penetration Test (SPT), hydraulic conductivity test, undisturbed and disturbed sampling, laboratory testing for soil-water characteristic curve, assessment of soil erodibility, direct shear test both conventional and with controlled suction. The results were in accordance with the type of soil and the literature. The proposed solution consisted of an alteration in the slope geometry, recomposition of vegetation cover and implementation of a superficial drainage system. A slope stability analysis was performed considering some suction effect on the shear strength of the soil.