The impacts of climate change on expansive soil movements in Australia

The effect of climate change on expansive soil movement has long been the greatest global challenge for built infrastructures. Numerous lightly-loaded residential buildings constructed on expansive soils are subjected to distortions arising from differential ground movements due to seasonal soil moisture (suction) changes. Thornthwaite Moisture Index (TMI) has been widely employed by geotechnical engineers to quantify expansive soil movement resulted from climatic variation. It is difficult to estimate the patterns of future soil movement due to the inherently highly variable nature of Victorian (Australia) climate, but it is likely that with the collected precipitation and temperature data, the TMI can be derived to infer depth of design soil suction change (H_s) which allows the characteristic ground movement (y_s) to be estimated. This paper outlines an overview of residential footing design in Australia. Three TMI isopleth maps of Victoria are also developed for the convenience of TMI users to infer H_s.