Some aspects of the compression and collapse behaviour of an unsaturated natural loess

José Munoz-Castelblanco (1) , Pierre Delage (2) , Jean-Michel Pereira (2) , Yu-Jun Cui (2)

1 navier umr 8205 - Laboratoire Navier
2 cermes - Géotechnique

The compression and collapse behaviour of a natural unsaturated loess from Northern France was investigated by running a series of constant rate of strain oedometric compression tests (together with some step loading tests) while monitoring suction by means of a high capacity tensiometer. The reasonably constant suction measured during constant water compression tests was linked to the collapse of the largest dry pores. Time dependent behaviour was also observed, with different responses obtained at different strain rates. In a standard fashion, collapse tests appeared to bring the representative point from the constant water content curve to the zero suction compression curve, indicating the existence of a maximum collapse stress. Data were qualitatively interpreted by using the Loading Collapse (LC) yield curve of the Barcelona basic model. Changes in the LC yield curve inclinations could account for the existence of a maximum collapse value.

Mots clés: natural loess; collapse; unsaturated; suction; loading collapse; time dependent

Domaines: Matériaux et structures en mécanique [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]

José Munoz-Castelblanco, Pierre Delage, Jean-Michel Pereira, Yu-Jun Cui. Some aspects of the compression and collapse behaviour of an unsaturated natural loess. Géotechnique Letters, 2011, pp.1-6. ⟨10.1680/geolett.11.00003⟩. ⟨hal-00655467⟩