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Forecasting the long-term deterioration of a cut slope in high-plasticity clay using a numerical model
journal contribution
posted on 2020-12-10, 14:27 authored by Harry Postill, PR Helm, Neil Dixon, S Glendinning, JA Smethurst, M Rouainia, KM Briggs, Ashraf El-HamalawiAshraf El-Hamalawi, AP BlakeThis paper details development of a numerical modelling approach that has been employed to forecast the longterm 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.
Funding
Assessment, Costing and enHancement of long lIfe, Long Linear assEtS (ACHILLES)
Engineering and Physical Sciences Research Council
Find out more...History
School
- Architecture, Building and Civil Engineering
Published in
Engineering GeologyVolume
280Publisher
Elsevier BVVersion
- VoR (Version of Record)
Rights holder
© The authorsPublisher statement
This is an Open Access Article. It is published by Elsevier under the Creative Commons Attribution 4.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/Acceptance date
2020-11-05Publication date
2020-11-16Copyright date
2020ISSN
0013-7952Publisher version
Language
- en