Undrained shear strength and stiffness behavior of natural stiff, geologically aged, plastic clays after undrained cyclic loading
File(s)
Accepted version
Author(s)
Pan, K
Shi, ZH
Yang, ZX
Jardine, RJ
Cai, YQ
Type
Journal Article
Abstract
The degradation of clay deposits under cyclic loading significantly affects slope and foundation stability, necessitating consideration in practical design cases. While the cyclic degradation behavior of postglacial soil is well-studied, understanding the impact on older, stiff, plastic clays is lacking. This study investigates undrained shear behaviors of three UK stiff clays deposited between the Eocene and upper Jurassic periods. Triaxial compression tests on K<jats:sub>0</jats:sub>-consolidated samples subjected to prior undrained loading cycles reveal reduced post-cyclic shear strength and secant Young’s modulus, with stiffness being more affected than strength. Compared to Holocene soft clays, these stiff clays exhibit substantial strength loss. Correlation between degraded strength/stiffness and cyclically induced pore pressure or applied cyclic stress ratio underscores the role of effective stress conditions resulting from prior cycling. The findings highlight the complexity of cyclic degradation in older, stiff clays and its implications for slope and foundation stability in engineering practice.
Date Issued
2025-06-23
Date Acceptance
2025-05-07
Citation
Canadian Geotechnical Journal, 2025, 62 (1), pp.1-17
ISSN
0008-3674
Publisher
Canadian Science Publishing
Start Page
1
End Page
17
Journal / Book Title
Canadian Geotechnical Journal
Volume
62
Issue
1
Copyright Statement
© 2025 The Authors. Published by Canadian Science Publishing. 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
Date Publish Online
2025-05-08