Organic matter in Swedish clays and its importance for quick clay formation
Swedish title: Organic matter in Swedish clays and its importance for quick clay formation
Author Rolf Söderblom
Series: SGI Proceedings
This report deals wlth the importance of, primarily, organic matter in Swedish quick clays. Particularly, the relationship between dispersing agents and sensitivity has been investigated. A study of a great number of reports in the SGI files showed that varved, fresh- water sedimented quick clays are relatively common in Sweden. The adsorbed double layer as well as the Donnan effect and the chemical equilibrium between double layer composition and pore water composition is discussed. The possibility that organic matter can form a fissured structure in the clay is also treated. Methods have been developed to isolate dispersing agents from Swedish clays and attempts made to analyse these agents. It is found that it is easy to isolate dispersing substances but very difficult to find substances with a known composition. Especially the humic acids are impossible to analyse at present. One group of dispersing substances which can be isolated, purified and chromatographed is the soaps. These are occurring in series of both saturated and unsaturated fatty acids. Another group that can be detected comprises the tensides. It has also been shown that dispersing agents isolated from quick clay can originate from impurities infiltrated in the ground.