Classify Plastic Soils Based on Undrained Shear Resistance in the Remolded State

Clasificar Suelos Plásticos con Base en la Resistencia al Corte no Drenado en Estado Remoldeado

Abstract

It is shown that the absolute value of the slope, m, of the log(Su)-log(w) line is closely related to the plasticity of the soil while the position of said line in the log(Su)-log(w) space ) is controlled by the content of non-plastic fines. On the other hand, it is also established that for any value of the Liquid Limit (LL), the value of, m, increases drastically as the Plasticity Index (PI) decreases while, for any IP the value of, m , increases slowly as the Liquid Limit increases. Consequently, it is possible to generate in the Plasticity Chart representative curves of the locus of soils with the same value of, m. On the other hand, it is established that the LL is related to the moisture content for the undrained shear resistance of the remoulded soil of 1.5 kN/m2. All these facts allow us to propose an alternative method to classify plastic soils based on the locus of the value, m, in the plasticity chart and the humidity at which the soil has a shear resistance of 1.5 kN/m2. It is good to note that the classification obtained with this method is identical to that obtained with conventional ASTM methods for Atterberg limits. Finally, it is also demonstrated that the content of non-plastic fines allows the value of m to be correlated with potentially liquefiable plastic soils.