Particle loss: An initial investigation into size effects and stress-dilatancy

McDougall, John; Kelly, Darren; Barreto, Daniel

Abstract

Drained triaxial tests have been performed to explore the effect of particle loss on shearing behaviour and critical states in granular mixtures. The mixtures comprise Leighton Buzzard sand (d50 = 0.8 mm), to which was added 15% by mass of salt particles of different nominal sizes: 0.063 mm, 0.25 mm and 0.5 mm. Shearing behaviours before and after particle loss (by dissolution) were compared. A good fit is observed between the test data and a stress-dilatancy relationship for the post-dissolution tests, highlighting the ability of the stressdilatancy analysis as a means to interpret the effects of particle loss on shearing. It was noted that critical state strength parameter M is determined by the post-dissolution grading regardless of size of removed particle. However, the duration of contractant volumetric strain increased with the larger removed particles (0.25 mm & 0.5 mm) even when initial specific volumes were virtually identical. It is suggested that a loose volumetric state is reached if the sand particle network is initially disrupted by the amount and/or size of salt particles, which following dissolution results in structural or fabric phenomena that are not reflected in scalar volumetric measures such as specific volume.

Citation

McDougall, J., Kelly, D., & Barreto, D. (2019). Particle loss: An initial investigation into size effects and stress-dilatancy. Soils and Foundations, https://doi.org/10.1016/j.sandf.2019.03.002

• Journal Article Type: Article
• Acceptance Date: Mar 5, 2019
• Online Publication Date: Apr 27, 2019
• Publication Date: 2019-06
• Deposit Date: Mar 15, 2019
• Publicly Available Date: Apr 28, 2020
• Journal: Soils and Foundations
• Print ISSN: 0038-0806
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1016/j.sandf.2019.03.002
• Keywords: Soluble soils, particle loss, laboratory testing, triaxial testing, stress-dilatancy
• Public URL: http://researchrepository.napier.ac.uk/Output/1568493
• Contract Date: Mar 18, 2019