Modeling of the Soil-Water Characteristic Curve—Case Study in Bom Brinquedo Hill’s, Antonina, Brazil

In this paper, we present a modeling of the soil-water characteristic curve for residual and sedimentary soils of BomBrinquedo Hill’s, located in Antonina, Brazil. This mountain range region is characterized as a natural disaster risk area, requiring continuous research related to the stability of the area. To obtain the soil-water characteristic curve, undisturbed samples of residual and sedimentary soil were collected, followed by suction testing using the filter paper method. Considering the bimodal characteristic presented by the soil, LABFIT software was employed for curve fitting using the generic formulation “Harris + C”. The results of the tests indicated that the phenomenon of hysteresis had a greater influence in situations with higher suction levels. When comparing the residual moisture values of the macropores between residual soil and sedimentary soil, the former exhibited the lower value. This suggests that the residual soil has a coarser grain size and larger pores, which facilitates the release of water retained in the soil’s macropores.