Estudo de estabilidade de talude semi-submerso, localizado à margem do rio Itacaiúnas, no município de Marabá

Abstract

The extraction of aggregates used in civil construction each day will be consolidated in the mining, which reflect in a local economy. In Maraba, the extraction of this mineral is done along the Itacaiúnas River, limited by extension and considerable height slope soil. Being an environment susceptible to geological and geotechnical changes, there was a need to conduct a study of stability in a slope. A preliminary study of the area was conducted, both by geological maps and research in situ, through the recognition of geological parameters. With respect to geology, it was found that the geology of the area of “Itapecuru” formation - sandstones interbedded with siltstones and mudstones- and “Sedimentary Cover” of the Araguaia, Tocantins, Itacaiúnas, Vermelho and Sororó Rivers - consisting of silts, clays, sands and gravels. In situ investigations it was found that the slope had circular failure, typical of soil slope, which enabled the back- analysis methodology for the determination of geotechnical parameters of interest: friction angle and soil cohesion. Thus, the factor of safety was adopted equal 1,0, in keeping the condition of collapse and by deterministic methodology was found numerically the friction angle and soil cohesion. Five experiments were performed to characterize physical getting as a result typical silty- sand soil, rock mass density equal 18,0 kN/m3 and humidity around 27,0%. From the results obtained, carried out the verification of the parameters needed to stabilize the slope, and thus found the slope angle according ground water conditions, in order that the slope is semi-submerged and submerged in Itacaiúnas River.