Salt in Swedish clays and its importance for quick clay formation. Results from some field and laboratory studies
Swedish title: Salt in Swedish clays and its importance for quick clay formation. Results from some field and laboratory studies
Author Rolf Söderblom
Series: SGI Proceedings
This report deals mainly with the importance of salt in Swedish clays. Especially the relationship between salt and sensitivity has been investigated. Methods have been developed by which the salt content in Swedish clays can be determined rapidly. A special instrument, "the salt sounding tool", has been used in the field to determine the approximate salt content in a clay. Rapid chromatographic methods have been developed and used to study the ionic composition of the pore water in clays. The salt conditions in clays from different parts of Sweden are discussed. It has not been possible to correlate the sensitivity of Swedish clays with the total salt content. There exists, however, a correlation between the ionic composition of the pore water of a clay and the sensitivity. Quick clays have an ionic composition which is not in accordance with the simple Donnan effect condition due to the presence of organic material in the clay. The investigation also shows that the strength properties of extracted samples of quick clay change with time. A method has been developed to detect slip surfaces in slides from salt soundings. The report also includes a study of the diffusion processes in clays as well as a laboratory investigation of the leaching processes.