Rheological Behaviour in a Clayey Soils

Abstract

Soils are the basis for production of the overwhelming majority of food, natural filers and wood. Most civil engineering operations are founded in the soil. Soil consists of three phases, that is, solids, water and air. It is important to understand the nature of the soil and the rheological properties. Site investigations for structures are focused on the mechanical properties of the subsoil at foundation levels and the corrosiveness of the groundwater. The type of foundation needed for a major structure is directly related to the strength of the underlying soils. Detailed site exploration may be required even at the preliminary design stage. The analytical data offer some values on particle size distribution, compaction, compression, consistence, lower and upper plastic limit, shrinkage limit, resistance to penetration, shearing strength, deformation resistance, and conventional pressure. The paper also presents some analytical data obtained in an experimental field, situated on a similar type of soil, relative to the draft requirement for plowing and the influence of the degree compaction on the level of agricultural production. The type of external force applied, time dependency and number of ploughings, scarifying’s or settlings and rolling’s can change properties down to deeper depths. The survey of soil indexes established for the foundation indicated a normal consolidation, the building plot, a plastic-viscous consistence and a great plasticity. The consequences of soil deformation and agricultural production are minimum in the variant with a double scarifying at 80 cm depth. The main rheological characteristics in the clayey soil from the area of locality Sânnicolau are: clay content varies between 39.8 to 45.9%, lower plastic limit 22.2-23.5%, upper plastic limit 48.9-55.0%, plastic limit 25.4-34.6%, void ratio (e) 0.85-1.00%, resistance to penetration 10-18kg/cm−2, consistency index 0.98-1.14, activity index 0.64-0.75%, shrinkage limit 22.7-15.4, deformation module 12.9-17.2 dan/cm−2, shrinkage-swelling index 0.78-1.01%.