Avaliação do parâmetro Ru de solos compactados em barragens de terra

Abstract

The construction of earth dams is a common practice in the history of humanity, however, even though construction techniques have evolved, these works are still subject to failure. The analysis of slope stability is the design phase that assesses the dam safety. In this type of construction, this analysis must be performed for different requests; the end of construction condition is one of them and considers that the filling of the dam has not yet occurred. In this condition, the generation and excess of neutral pressures due to the increase of vertical loads during the execution of the soil layers must be considered, since these requests reduce the staility. For a better evaluation of the slope stability conditions, the Ru parameter, which represents the ratio of the increase in poropressure in relation to the increase in vertical stress, must be considered in the calculation methods. Thus, this research evaluated the the development and factors that influence the parameter, in addition to checking the consistency of the Ru values used in projects in the state of Ceará (Brazil) for compacted soils of earth dams, in the condition of final construction. It is concluded, from the analysis of the tests and literature data, that the parameter has a high variability of behavior and that it tends to be sensitive to soil lithology and its classification. In addition, it was also possible to verify that the values ​​usually adopted in projects in Ceará (Brazil) may not adequately consider the development of neutral pressures in the massifs.