Effects of temperature and relative humidity on a clay embankment: centrifuge modelling

Abstract

Climate change studies have increased in recent years focusing on the complex interactions at the soil–atmosphere interface. This note describes a new centrifuge environmental chamber, which is capable of separately controlling temperature and relative humidity (RH) as climate boundaries, to investigate the de-coupled influence of temperature and RH as atmospheric boundaries on a clay embankment. Temperature changes are imposed through convection cycles and radiation, while vapour diffusion is employed for RH cycles. Generally, it is found that temperature cycles induce more significant shrink–swell behaviour compared with RH cycles. This is because effects of changes in temperature on volumetric strains of soil occur more rapidly in the short term compared with RH. Compared to convection, imposed heating through radiation results in 50% more heave for the applied range of radiation. This is because higher temperatures and a deeper influence depth associated with radiation heating leads to increased thermal expansion of the soil.