ON THE RHEOLOGICAL CHARACTERS OF CLAY

This is a report of a theoretical research on the rheological properties of clay. In this paper, the authors indicate that the representation of clay by the complex combination of simple mechanical model units causes the complication on the mathematical treatment, but does not always contribute to the analysis of essential nature of clay, and insist that the solution of Theological behavior of clay should be treated with the theory deduced from the micrometric stand point.From this standpoint, applying the structural viscosity derived from the staistical mechanics on viscosity of clay, a new fundamental formula concerning the deformation or strength characters of clay—such as creep, creep failure or secondary compression is derived. This formula well agrees with the various kinds of experiments—experiments on compression creep, recovery, creep by repetitional load, yielding, failure, secondary compression etc.. Furthermore, results of tests on creep, yielding, failure or thermal effect can be explained micrometically by this formula.Applying the formula and experiments, some important problems on soil structure—such as strength water content relation, relation between yielding value and failure strength, time lapse necessary for failure, variation in strength by creep, final value of secondary consolidation—are investigated and a new measuring method of yielding value of clay is proposed.