Behavior and modeling of silt-clay transition soils

Abstract

Natural soil deposits are often composed of particles of different sizes and base minerals. Such variations generally preclude characterization of natural soils into a single soil type such as a gravel, sand, silt or clay. The mechanical behavior of such soils can vary quite considerably spatially within a soil deposit. The soil formation process involves variable particle size distribution from one location to another. This gives rise to the creation of an array of soils that transition from one general soil type to another within essentially similar deposits. Such materials are thus commonly referred to as transition soils and are very abundant in the world. The effect of non-plastic silt content on the behavior of silt-clay soils is not fully understood. This is due to a lack of laboratory tests that isolate silt content from clay mineral type, pre-consolidation histories, loading direction, and loading rate. This paper gives an overview of the experimentally measured behavior of silt-clay transition soils and their characterization using the Generalized Bounding Surface constitutive model.