This project is funded by the EPSRC and forms a unique opportunity uniting 6 academic institutions and coalesce their field, laboratory and computing facilities; with a large cohort of PhD students and experienced stakeholder community in close collaboration as iSMART project partners we undertake world leading science and create a long-term legacy.
Individually, the partners in this proposal, in collaboration with key infrastructure owners and engineering companies, have been responsible for the instrumentation of 15 cut slopes and embankments, the development of numerical models which couple hydrological and geotechnical effects, and the development of laboratory and filed testing to provide parameters to populate these models.
These studies have helped to define the type of problem that is being faced and begin to understand some of the interactions between weather, soil and vegetation. However, further research is required in order to better understand
- material behaviour (particularly the composite behaviour of soil, water, air and vegetation);
- slope system behaviour (particularly the effects of temporal and spatial variations of material properties)
- and the relationships with environmental effects and engineering performance.
Furthermore, the integration of the material and slope behaviour with that of the behaviour of the infrastructure network as a whole has thus far not been possible.
It is important for the sustainable management of infrastructure slopes (assessment, planning, repair, maintenance and adaptation) to have models that can assess the likely engineering performance of infrastructure slopes, both now and in the future. Recent model development has started to consider the input of weather patterns, and can therefore model the potential effects of future climate. However it has become clear that these models are sensitive to the way in which a number of the physical processes and properties are incorporated, many of which are complex and difficult to quantify directly. A better understanding of the interactions between earthworks, vegetation and climate is required to formulate robust guidance on which maintenance approaches should be adopted and how they should be applied.
iSMART will use a combination of field measurements, lab testing and development of conceptual and numerical models to investigate the uncertainties and knowledge gaps enumerated above and to visualise the complex interactions taking place over time and space. This knowledge will help the managers of the UK's transport infrastructure to identify problem sites, plan and prioritise maintenance activity, and develop assessment and adaptation strategies to ensure future safety and resilience of geotechnical transport infrastructure.
Our contention is that understanding water movements in slopes is the key to understanding material (property) and structural behaviour and thus unlocking our ability to design effective and sustainable asset management systems for a resilient infrastructure.
Our vision is to create a (4D) visualised dynamic model of transient water movement in infrastructure slopes under a range of current and future environmental scenarios which can be used to create a more reliable, cost effective, safer and more sustainable transport system.
Our hypothesis is that by developing a fundamental understanding of earthwork material and system behaviour we will be able to provide the sustainable engineering assessment, maintenance and adaptation tools and strategies needed to maintain future infrastructure resilience, reliability and safety.
Our aims are to understand materials (particularly clay fills) and system behaviour (the soil-water-vegetation system of a single slope (scale 1) and the systems of slopes (scale 2) that make up a transport network (scale 3)) under current and future, forecasted weather event sequences and to be able to integrate the understanding across these 3 scales. In particular the differences in cyclic material behaviour resulting from wetting/drying in clay soils/fills, the impact of vegetation type and coverage, and the influence of the large regional variations in geology and climate (and how the climate will change). Our aim is also, through collaboration with the key asset owners, to use this scientific understanding to inform advanced inspection, monitoring, maintenance and repair regimes. Furthermore, the legacy of this project will be a co-ordinated community of researchers and stakeholders equipped with a virtual research centre (field sites, advanced models, data sets) to continue to meet the challenges of providing sustainable infrastructure.
Delivering these objectives requires the integration of: laboratory testing (to provide critical understanding of material behaviour and property relationships); extensive field monitoring (to understand mass material and slope system behaviour, the implications of construction, vegetation and other near surface features, and to validate numerical models), and numerical simulation (to inform advanced asset management procedures and forecast infrastructure capacity reduction).