Determinação do potencial de liquefação estática de uma areia fina

Abstract

Failures caused by liquefaction have been showing catastrophic consequences all around the world, such failures are more common in mining sector, for instance, in tailings dams, which is why the phenomenon has been widely studied. This rupture is characterized by an abrupt loss of undrained strength, observed after peak. There are several prerequisites for a given soil to be susceptible to liquefaction, among which the following stand out: grain size curve, relative density, saturation, etc. In cases where the phenomenon has been reported, the soil undergoes a change in physical state, starting to behave like a liquid. However, there is some ambiguity in the definition of liquefaction. For some authors liquefaction is characterized by the strain softening process of the soil, that is, by the fragile rupture that the soil presents, while other authors treat as liquefaction materials that presented their shear strength equal to zero, which is observed through stress path that lead to the place where p and q are equal to zero, denominating this as true liquefaction. The present research shows a series of results from undrained triaxial tests on uniform sand with round grains from Rio de Janeiro. Several methodologies for molding specimens of triaxial tests were also studied. In addition was determined the critical state line and the flow liquefaction line. The stress paths obtained from various results of undrained triaxial tests show a tendency of true liquefaction, as observed by tests done on waste from the Stava mine - Italy, despite some trajectories not reaching the origin of their respective axes. However, was observed that the flow liquefaction line was not unique.