Intermediate till soil properties and distinctive features

Abstract

All the sediments discharged from the Quaternary glaciers differ in their granulometric and mineral composition. Tills, sands, and clays cover unevenly sized areas in various places. However, during engineering geological and geotechnical investigations, the most found types of till soil are sandy low plasticity clay (saClL), sandy low plasticity clay-silt (saClL-SiL), and clayey sand (clSa). The last two mentioned are intermediate till soils which are mostly assigned as Medininkai glacial deposits. The analyzed intermediate glacial till deposits are distributed in the eastern part of Lithuania, where the biggest and the most complex buildings are being designed. During the research, about 80 moraine samples from the entire territory of Lithuania were investigated. Several samples were analysed using an SEM microscope. From all the obtained data a database was created, where all the data was summarized and analysed in P.K Robertson’s graphs with SBT (Ic) zones. After research, intermediate till soil is characterized by low natural moisture content and high natural density, and it practically always has low plasticity, so the porosity rate of these soils is relatively low. This soil is less compressible. Investigated soil during this study mainly takes the position into P.K Robertson’s graphs zones 4 (Silt mixtures) and 5 (Sand mixtures) mixtures where the Ic zone is 2.60. After research with an SEM, it can be stated that clay mineral mixtures (illite-smectite) and not clay minerals predominate in the investigated soils’ clay fraction.