Mechanical behaviour of compacted scaly clay during cyclic controlled-suction testing

Scaly clays are stiff and highly fissured soils due to their complex geological history. Owing to these characteristics, they may be placed and compacted as excavated, to obtain a material with adequate engineering properties, suitable as core material in earth dams and in waste isolation fills. With reference to these engineering applications, an exhaustive experimental programme is developed to characterise the hydro-mechanical behaviour of this compacted material under a variety of controlled-suction paths. This paper presents selected test results, focusing on the interpretation of specific behavioural features of the volume change of this complex material; namely, the strain accumulation and the volumetric irreversible features developed during suction cycling at different stress levels.