Geotechnical behaviour of different organic matter on clayey soils

摘要

The geotechnical behaviour of organic clayey soils is always unpredictable as it depends on various parameters like organic matter, organic percentage, soil type, aggregate stability and environmental conditions. A substantial change in the plasticity characteristics on drying is also one of the major concerns of geotechnical engineers. In this paper, an attempt has been made to study the effect of organic matter (Urea, compost, and starch), organic percentages (5%, 10% and 15%), soil type (clay content 20%, 40% and 60%) and aggregate stability on geotechnical properties of soil. Various Laboratory tests like unconfined compressive test, Atterberg limit and one-dimensional consolidation tests were conducted on artificial organic clays to understand the influence of each parameter. The test results reveal that the behaviour of organic content in soil is complex. The plasticity index decreased with increase in organic content. The shear strength of soil varied with soil type and organic matter. It is noted that the strength of the artificial organic soil greatly depends on the aggregate stability of the organic matter. Consolidation settlement of soils increased with the organic content and the effect depended on the type and amount of organic content. These effects were confirmed by the physio-chemical characterisation of the organic clayey soils.