Application of Transformed and Normalized Models for Hydraulic and Mechanical Characterization of Granite Residual Soils

The behavior of unsaturated soils is predominantly controlled by variations in matric suction, with its effects analyzed based on the water retention curve, which depends on chemical and physical factors such as the void ratio, zero point of charge (PCZ), pH etc. Studies show that the relationship between the logarithm of suction (in centimeters of water column) and the void ratio results in a unique behavior, enabling analyses under unsaturated conditions. This study evaluates a model of transformed and normalized characteristic curves, considering hydraulic properties derived from retention curves and mechanical properties obtained from cohesive intercepts (τvs ua – uw)) under compacted and natural (intact) conditions. The hydraulic model revealed different pore distributions and its applicability in estimating initial saturation as a function of the void ratio. On the other hand, the mechanical normalization model demonstrated accuracy, with a determination coefficient (R2) of 0.83. These results highlight the feasibility of normalization for analyses of unsaturated soils, specially for estimating hydraulic and strength parameters across varying void ratio.