A COMPARATIVE ANALYSIS OF THE INFINITE SLOPE MODEL AND A PHYSICALLY BASED MODEL CONSIDERING DIFFERENT DIGITAL ELEVATION MODELS

Slope stability models: a comparative analysis in defining the safety factor

Abstract

The ratio between the rupture force acting on a material and its ability to resist is used to evaluate mass movement processes. Stability assessment methods are based on mathematical equations that predict the exact relationship between the independent variables of shear stress and shear strength. This study aimed to analyze the calculation of the safety factor (SF) based on infinite slope and a deterministic, transient mathematical model, considering two different digital elevation models (DEMs). The experimental area is a basin located in the municipality of Itaoca, São Paulo, which experienced mass movements in 2014. The DEMs were pre-processed, and the SF was obtained using different models. The maps were then examined in comparison to an inventory of landslide scars. The findings indicated that the main difference in the models' responses was due to the scar concentration, suggesting that the transient model produced a higher proportion of cells with low SF than the infinite slope model. The predominant slope within the scars was consistent with the findings of other studies. Rasterizing the scars resulted in the affected areas being resized, a matter that warrants further investigation.