Effect of fines content on the monotonic shear behavior of sand-clay mixtures

In most design codes, soils are classified as either sand or clay, and appropriate design equations are used to represent their behavior. For example, the behavior of sandy soils is expressed in terms of the soil's relative density, whereas consistency limits are often used for clays. However, sand-clay mixtures, which are typically referred to as intermediate soils, cannot be easily categorized as either sand or clay and therefore a unified interpretation of how the soil will behave at the transition point, i.e., from sandy behavior when fines are low, to clay behavior for high fines content is necessary. In this paper, the monotonic shear behavior of sand-clay mixtures was investigated by considering changes in fines content and compaction energy, while paying attention to the void ratio expressed in terms of the coarser-grain matrix. It was observed that the monotonic shear strength of sand-clay mixtures is dependent on the granular void ratio.