Exploring the linkage between mechanical behaviour and particlescale interaction of kaolinite
File(s)
Accepted version
Author(s)
Nakamichi, yohei
O'Sullivan, Catherine
Tangney, Paul
Angioletti-Uberti, Stefano
Bandera, sara
Type
Journal Article
Abstract
The response of clay to mechanical compression is highly dependent on its stress history. Generally, normally consolidated clays exhibit a relatively soft response, while over-consolidated clays exhibit a much stiffer response upon reloading. In the literature this difference has been qualitatively attributed to differences in clay microstructure. This paper uses coarse-grained molecular dynamics simulations to propose that an additional contribution comes from the non-linear, non-monotonic relationship between the inter-particle forces and the separation distances. At large separation distances, clay particles
interact via repulsive non-contact forces when the particles initially become close enough to interact. The strength of the mutual repulsion increases with decreasing separation until a maximum repulsive interaction energy, termed an energy barrier, is reached. Once this energy barrier is overcome, the particle interactions become attractive so that the particles effectively become bonded to each other. This paper uses a new approach to interaction models for particle-scale simulation to show that the compressive forces experienced by particles under engineering stress levels are sufficient to push particle pairs into this
attractive force regime; and that, upon subsequent unloading, these particles remain bonded to each other. The difference in macro-scale compressibility between normally
consolidated and over-consolidated clays can be explained, at least in part, by this attraction and by particles irreversibly bonding together
interact via repulsive non-contact forces when the particles initially become close enough to interact. The strength of the mutual repulsion increases with decreasing separation until a maximum repulsive interaction energy, termed an energy barrier, is reached. Once this energy barrier is overcome, the particle interactions become attractive so that the particles effectively become bonded to each other. This paper uses a new approach to interaction models for particle-scale simulation to show that the compressive forces experienced by particles under engineering stress levels are sufficient to push particle pairs into this
attractive force regime; and that, upon subsequent unloading, these particles remain bonded to each other. The difference in macro-scale compressibility between normally
consolidated and over-consolidated clays can be explained, at least in part, by this attraction and by particles irreversibly bonding together
Date Issued
2026-02-24
Date Acceptance
2025-08-26
Citation
Geotechnique: international journal of soil mechanics, 2026, 76 (2), pp.302-319
ISSN
0016-8505
Publisher
ICE Publishing
Start Page
302
End Page
319
Journal / Book Title
Geotechnique: international journal of soil mechanics
Volume
76
Issue
2
Copyright Statement
© 2025 Emerald Publishing Limited. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Publication Status
Published