An atmospheric chamber for the investigation of the effect of seasonal moisture changes on clay slopes

摘要

It has been theorised that seasonal pore water pressure cycles play a significant role in the progressive failure of clay embankments. This paper presents the development of an atmospheric chamber to build on the recent advances in techniques for matric suction measurement and texture-based image analysis of deformations to model these cycles in the centrifuge. The systems for regulating the relative humidity boundary condition are described, and the importance of a near-zero moisture loss environment emphasised. Through control of the relative humidity boundary condition, idealized seasonal pore water pressure cycles have been successfully created in the centrifuge. The resulting deformations observed over two years of modelling of an overconsolidated clay slope are presented. These results indicate that, although most of the deformation is normal to the soil slope, seasonal moisture cycles cause small, yet irrecoverable downslope displacement components.