ABSTRACT
Expansive soils undergo excessive volumetric deformations during seasonal and annual wetting-drying cycles. Owners of infrastructure take extreme actions to mitigate expansive soil effects, however, the problem can be worsened rather than improved. Physical modelling in a centrifuge environment of expansive soil models allows for several wetting-drying cycles to be applied within a reasonable time period and for direct observation of the development of subsurface strains in response to wetting-drying cycles. This paper describes physical modelling of a road cross-section constructed in expansive soil and subjected to wetting-drying cycles utilising a new atmospheric chamber. This investigation examined the differential vertical subsurface displacement of the distinguishable features of the model including the impermeable road surface, adjacent drainage ditch, and far field. The results indicate centrifuge technology coupled with the atmospheric chamber’s ability to control weather conditions can be used to measure the differential subsurface deformations of the soil-structure when exposed to cyclical wetting-drying events. These preliminary observations will provide the fundamental procedures and understanding to scope future investigations to aid government departments of transportation in optimising construction methods to increase sustainability of infrastructure in expansive soil areas.
