Estudo de resistência ao cisalhamento de solos utilizados na construção de barramentos de pequeno porte

Abstract

The present study has objective to investigation the behavior of shear strength as of three till soils, from the Alegrete/RS city, with the purpose to using such materials inth building of barrages of small size dams. For this, firstly collected samples from three distinct soils types, at diferents geological formations. Then, were made tests in the laboratory for geotechnical characterization tests, such as granulometry, specific gravity of the soil grain solids, liquid limit and plastic limit. Also, with in order to get obtain mechanical improvements, was made compactation tests, using the Standard and Modified Proctor. After, with intentionto do shear strength tests, prepared small proof bodies, molding optimum moisture content and maximum dry density of soil, corresponding to compactation tests. After 28 days, the proof bodies were submitted to shear strength tests, using a minimum speed to 0,025 mm/min. The results obtained allowed to verify that the use of higher compactation effort influence on increase maximum dry density of soil and parameters of shear strength. From the data obtained in the laboratory and field, it was possible to generate the typical cross sections of the reservoirs to simulate the slope stability in geotechnical software, considering the properties of the materials with which they were built and the influence of the water level. Analyzes of safety factors expressing slope conditions revealed them to be "unstable" and "stable but not safe" in the standard Proctor effort and "stable and safe" in Modified effort, for downstream and upstream.