Análise geomecânica de encostas em municípios do agreste pernambucano.

Abstract

The occurrence of mass movements, which took place in large numbers in 2022, on the banks of Highway PE-177, the road linking the municipalities of Quipapá and Garanhuns, in the arid zone of Pernambuco, sparked our interest in analyzing the geomechanical behavior of these slopes belonging to the Borborema Plateau, with the aim of investigating the factors that caused these events. The investigation included analyzing the factors according to the literature, as well as collecting samples for laboratory tests. The investigation led us to conclude that the rainfall recorded in the region in 2022 was more than double the historical average, a factor intrinsically linked to the events. Using the Unified Classification System (USCC), we found that the two samples are classified as clayey (CH), with high compressibility, as they both have LL >50. When they were subjected to the direct shear test, the soil decreased as the humidity increased (saturated condition), while the friction angle did not change much. The steepness of the slopes contributes directly to the occurrence of landslides, because the steeper the slope, the greater the increase in density, which reduces cohesion, creating overload and leading to rupture. The vegetation on the slopes also contributes to the landslide phenomenon.