As the runner-up of the 2021 BGA Cooling Prize, GCG’s Dr Riccardo Scarfone was invited by Ground Engineering to submit a paper on the content of his presentation. His article, titled “Capillary Barrier Systems for Prevention of Rainfall-induced Slope Instability” is now published in the March 2022 issue of Ground Engineering Magazine (https://www.geplus.co.uk/digital-edition/march-2022/). It was co-authored with Prof Simon Wheeler (University of Glasgow) and Dr Colin Smith (University of Sheffield).
Slope instability is often caused by decreases in suction due to heavy and prolonged rainfall. In this study, the application of capillary barrier systems (CBSs) for suction control and slope stabilization purposes (i.e. reducing the risk of rainfall-induced slope instabilities) is analysed numerically. Well-designed CBSs have the capacity to limit the percolation of water into the underlying soil and slope and was shown, in the study, to be effective at increasing the minimum values of suction attained in the underlying ground, thereby resulting in improved stability of the slope. The figure illustrates the principal mechanisms involved.