This year’s Géotechnique Lecture will consider how to use the benefits of vegetation in geotechnical engineering
Vegetation is often found near infrastructure, including on natural and man-made slopes alongside transport corridors. Plant roots offer potential benefits for use as a low-cost, carbon-neutral natural alternative to conventional ground reinforcement techniques.
iThs topic will be explored by University of Dundee discipline lead for civil engineering Jonathan Knappett during the 13th Géotechnique Lecture in November. Despite the potential benefits plant roots are rarely incorporated explicitly within geotechnical design, principally due to perceived issues of unpredictability in location and variability in biomechanical root properties.
Though earthquakes are rare in the UK, the use of vegetation to improve the seismic performance of slopes will initially be considered. It will be shown how the study of this specific problem is particularly useful when physical modelling is to be undertaken.
Centrifuge testing, combined with a novel use of 3D printing to produce repeatable and highly representative scale model root analogues, will establish that plant roots can be just as effective in improving slope stability as conventional methods.
Knappett will also show how the mechanical reinforcement from roots observed in the centrifuge may be incorporated into routine limit analysis or finite element simulations.
Such analyses demonstrate a fundamentally different mechanism by which roots improve stability, with knowledge of root spread and depth being at least as important as outright biomechanical root strength.
Novel approaches for determining these input parameters using recently developed rapid in-situ testing techniques will be introduced.
Knappett will conclude by exploring how this new insight and modelling approach may be applied to a wider range of practical problems including extending the design life of slopes in seismic areas and under the effects of climate change; the effect of tree removal on stability of railway embankments; use of vegetation in debris-flow protection systems; and understanding wind-throw hazard from storms.
Knappett believes that use of vegetation can become a realistic eco-friendly technique for use in practical geotechnical engineering.
The event will be held at the ICE in London on 14 November and will start at 6.30pm.