The analysis of the total stress strain response of an expansive clay subgrade at macalister, Queensland

Attempts to characterize materials for mathematic analyses and design of road pavements using the results of repeated loading triaxial tests have previously considered the recoverable and irrecoverable behaviour as separate and independent phenomena. This is not so in practice and this paper shows how the irreversible total stress strain response of the materials can be characterized and modelled using hyperbolic relations derived from repeated loading triaxial test data. The experimental work was carried out on an expansive clay subgrade material from macalister, Queensland, which exhibited non linear moisture dependent stress strain response. These responses could be modelled closely by the hyperbolic relations used in finite element analyses of the repeated loading triaxial tests themselves. When a typical pavement structure was analysed, the recoverable and irrecoverable responses calculated from the total response were not significantly different from the separate and independent analyses of these responses. This suggests that the methods previously used, and that proposed in this paper would give similar results in this case.