Initial Moisture Content Bias In The Shrink-Swell Test Maintained

Nathan McDougall and Nick Rogers

Abstract

Following our presentation to the NZGS (Rogers and McDougall, 2020), a paper was published in Australian Geomechanics titled “On the Common Criticism of Initial Moisture Content Bias in the Shrink-Swell Test”, which sought to defend the shrink-swell test against our conclusion that it is flawed (Fityus and Burton, 2020). The present paper is offered by way of response.

Fityus and Burton offer interesting ideas related to the role of suction, and the variability of soil. However, our data analysis, since published in full (Rogers et al., 2020), still raises important concerns which have not been satisfactorily addressed. This is especially so with respect to the break-down of contributions from each of the shrink and swell strain components which readily show that in all cases (including Australian datasets) there is not an inverse relationship between the swell strain and the initial moisture content, which would be necessary for the shrink-swell test to properly remove the initial moisture content bias.