Notes on the compressibility of clays

Abstract

The consolidation of an argillaceous sediment may be simply described as the process by which it is compressed from a mud into a clay and finally, if the weight of the overburden is sufficient, into a shale. 1 This process is of importance in the interpretation of geological structure, and on a smaller scale it has an application in the design of foundations for engineering structures, since the weight of a structure founded on clay will cause settlements due to consolidation, and the magnitude of these settlements must be know. The practical aspects of consolidation have been considered in several papers in geological and engineering literature. In the present paper we shall be concerned with a quantitative study of the process of consolidation in argillaceous sediments, and the objects of our investigation will be as follows: (1) to examine the compressibility of a number of different types of clay, as demonstrated in laboratory consolidation tests; (2) to present field data on the compressibility of clays in nature; (3) to compare the ture compressibility of clays in nature with that found in the laboratory tests. The first experimental work on consolidation was published by K. Terzaghi in 1921 and 1923. This was collected together and considerably expanded in the book Erdbaumechanik which was published in 1925 and which formed the basis of the new applied science known as soil mechanics. In 1927 the same author gave results of laboratory consolidation tests on several different clays and showed that the compressibility was greater