SLOPE SAFETY IN ANTHROPIC OCCUPATION SITUATIONS: CRITERIA FOR ANALYSIS AND EVALUATION OF GEOLOGICAL RISKS

Abstract

Geological hazards on slopes primarily refer to gravitational mass movements, which involve the detachment of part of the weathering mantle covering the uppermost rock layer. The material—comprising residual soils and possible rock fragments—detaches and subsequently slides down the slope. Landslides have multiple causes, but they occur most frequently during intense rainfall events due to internal forces acting as pore water pressure. The damage caused by such geological events is significantly greater when human occupation exists on the slope, particularly in the form of informal or irregular residential settlements. Assessing slope stability against gravitational phenomena involves complex engineering processes that rely on diverse parameters and data, often subject to significant uncertainties. In practice, when instability is identified, corrective intervention is implemented. These interventions are categorized as: extensive actions, applied to low-to-moderate risk scenarios through preventive measures; or intensive actions, employed in high-risk situations through structural engineering works. Among these, structural (singular) interventions demand the most rigorous engineering analyses, as they are defined by deterministic methods guided by technical standards. This study evaluates the standard methods used to determine the safety of slopes and soil-interacting structures under serviceability and ultimate limit states, highlighting the difficulties and uncertainties that may affect the results.