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Lookup NU author(s): Dr Peter Helm,
Professor Stephanie Glendinning,
Dr Mohamed Rouainia
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2020 The Author(s). This paper details development of a numerical modelling approach that has been employed to forecast the long-term performance of a cut slope formed in high plasticity clay. It links hydrological and mechanical behaviour in a coupled saturated and unsaturated model. This is used to investigate the influence of combined dissipation of excavation-generated excess pore water pressures and seasonal weather-driven near-surface cyclic pore water pressures. Deterioration of slope performance is defined in terms of both slope deformations (i.e. service) and factor of safety against shear failure (i.e. safety). Uniquely, the modelling approach has been validated using 16 years of measured pore water pressure data from multiple locations in a London Clay cut slope. Slope deterioration was shown to be a function of both construction-induced pore water pressure dissipation and seasonal weather-driven pore water pressure cycles. These lead to both transient and permanent changes in factor of safety due to effective stress variation and mobilisation of post-peak strength reduction over time, respectively, ultimately causing shallow first-time progressive failure. It is demonstrated that this long-term (90 year) deterioration in slope performance is governed by the hydrological processes in the weathered near surface soil zone that forms following slope excavation.
Author(s): Postill H, Helm PR, Dixon N, Glendinning S, Smethurst JA, Rouainia M, Briggs KM, El-Hamalawi A, Blake AP
Publication type: Article
Publication status: Published
Journal: Engineering Geology
Print publication date: 01/01/2021
Online publication date: 16/11/2020
Acceptance date: 05/11/2020
Date deposited: 07/01/2021
ISSN (print): 0013-7952
ISSN (electronic): 1872-6917
Publisher: Elsevier B.V.
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