Dilatancy phenomenon study in remolded clays – a micro-macro investigation

Qian-Feng Gao (1) , Mohamad Jrad (1) , Lamine Ighil Ameu (1) , Mahdia Hattab (1) , Jean Marie Fleureau (2)

1 LEM3 - Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux
2 MSSMat - Laboratoire de mécanique des sols, structures et matériaux

The aim of this study is to analyze the influence of stress path on the dilatancy behavior of clays. Triaxial tests were conducted on saturated, remolded clay specimens. During triaxial loading, two different stress paths were considered to bring the stress level to a given point in the (p' - q) plane. After triaxial testing, scanning electron microscopy (SEM) observations and X-ray microtomography (XR-μCT) scans were performed on subsamples. The obtained images were processed using different software and thus the geometric characteristics of pores and cracks were identified. The microstructural characteristics were linked to the dilatancy phenomenon of specimens. The results indicate that dilatancy is influenced by stress path and may be attributed to the evolution of pore geometry and the presence of local open cracks in highly over-consolidated (OC) clays..

Mots clés: Clays; Cracks; Dilatancy; Pore orientation; Stress path

Domaines: Sciences de l'ingénieur [physics]

Qian-Feng Gao, Mohamad Jrad, Lamine Ighil Ameu, Mahdia Hattab, Jean Marie Fleureau. Dilatancy phenomenon study in remolded clays – a micro-macro investigation. China-Europe Conference on Geotechnical Engineering, 2016, Aug 2016, Vienna, Austria. pp.148-152, ⟨10.1007/978-3-319-97112-4_33⟩. ⟨hal-02460157⟩