Relationship Between Undrained Shear Strength with Atterberg Limits of Kaolinite/Bentonite – Quartz Mixtures

Abstract

The main purpose of this study was to investigate the relationship between the undrained shear strength and the Atterberg limits of quartz clay mixtures using the falling cone test and the Casagrande method. As a result, the penetration depth obtained from fall cone test, which determines the liquid limit close to the value obtained by the Casagrande method, was changed by the presence or absence of fine grained soils. It was shown that same clay type with a much higher quartz content concluded smaller undrained shear strength values. The undrained shear strength value with a small amount of quartz was the lowest; increasing with the increase in fines content. The relationship between the undrained shear strength and the Atterberg limits for all the samples depend on three parameters: (1) quartz / clay (kaolinite or bentonite) mixtures ratio, (2) type of clay (plasticity; high - low plasticity), and (3) plastic limit value. Finally, an equation for the fall cone test used to determine the Atterberg limit of quartz clay mixtures, was proposed based on the undrained shear strength and initial water content.