Characteristic Curves in Erodible Soils on a Slope in Cabo De Santo Agostinho/Brazil

Several studies focus on the characteristic curve of the soil, which plays a fundamental role in the mechanics of unsaturated soils and is also an important indicator of the physical quality. Therefore, the objective of this research was to determine the characteristic curve of the soil by the methods of Filter Paper, Richards Pressure Chamber, and Haines Funnel on an erodible slope in the Metropolitan Region of Recife, in the state of Pernambuco, Brazil. The curves were designed by the models of van Genuchten, Fredlund & Xing, Seki, and Dunner. In the suction x humidity ratios, during the wetting and drying processes, the experimental points were very close, making it difficult to define the hysteresis effect. The Richards Chamber and Haines Funnel methods allowed the complementation of the characteristic curve for low suction values, indicating that the techniques can be used simultaneously. The statistical analysis resulted in a numerical model with a significance value greater than 97%.