RECENT QUICK-CLAY STUDIES .7. SENSITIVITY OF ARTIFICIALLY SEDIMENTED ORGANIC-FREE ILLITIC CLAY

A series of experiments with artificially sedimented illitic clay was carried out with the purpose to investigate if quickness could be produced by leaching of a clay deposited in salt water. In order to reduce the influence of such factors as organic constituents, a high silt content or a particular mineral composition, a fine-grained organic-free illite clay and an artificially produced salt water were used. The elimination of organic substances was obtained by a prolonged treatment with hydrogen peroxide of the dry clay material. It was found that the organic matter was very firmly bound to the mineral phase. No marked sensitivity change was caused by the leaching. It was concluded that leaching may no be a sufficient condition for the formation of quick-clay. This is in direct contradiction with the results from similar tests by Bjerrum and Rosenqvist (1957). The discrepancy is discussed with special reference to the fact that Bjerrum and Rosenqvist used a clay material which was known to be a quick- clay in its natural state. Such a material may have an organic content which governs the remoulded shear strenght in the leached state. © 1969.