A CRITICAL-STATE INTERPRETATION OF SOIL COMPACTION BY ANISOTROPIC CONSOLIDATION

A seven parameter model for the compaction of a soil by anisotropic consolidation has been proposed by Grisso, Johnson and Bailey, and they established the values of the parameters by extensive testing of four soil types. They have developed this model to meet boundary conditions at zero and very high stresses, and suggested that it should be used to replace the conventional two parameter semi-logarithmic representation for specific volume or density. This paper uses their data to show that the semi-logarithmic model is at least as accurate as their more complex model, provided that the two parameters are functions of the ratio of principal stresses imposed during the compaction. It is also shown how Critical State concepts can be used to locate the data in Critical State space, leading to the definition of an alternative two parameter model which is applicable for all stress ratios, and which offers the same accuracy as the seven parameter model. © 1993 Silsoe Research Institute.