Space Weather disruption of the near-Earth space- and ground-based systems is now accepted as having significant socio-economic impact , and is included in the UK National Risk Register for Civil Emergencies as a medium-high likelihood and medium impact civil emergency. Specifically, the UK National Risk Register identifies that "(c)urrent understanding is that a severe space weather event could have impacts upon a range of technologies and infrastructure, including power networks, satellite services, transport and digital control components" and that any industry relying on satellite services, that "(s)evere space weather can interrupt satellite services including Global Navigation Satellite Systems, communications, and Earth observation and imaging systems by damaging the space-based hardware, distorting the satellite signal or increasing the errors in ground-based receivers." The potential impacts of space weather on technological infrastructures, including power grids, satellite and ground communications and navigation systems, have generated world-wide interest at government levels in developing both forecasting and mitigation techniques and strategies. Indeed, the UK government is now seeking to establish a centre for space weather forecasting within the Met Office, who represent the state-of-the-art in forecasting terrestrial weather and can apply their 150 year heritage in forecasting to the field of space weather. The effects of extreme space weather can only be estimated since we do not know it's full extent. However, the potential total cost of an extreme Space Weather event has been estimated as around $2 Trillion in year 1 in the U.S. alone, with a 4-10 year recovery period . Quantifying the effects of Space Weather in all its forms is therefore of paramount importance. Less work has been undertaken in wider infrastructure sectors i.e. beyond those that coincide with technological infrastructures discussed above such as electricity distribution, communications and aviation. However, other infrastructure sectors exhibit important vulnerabilities to space weather, both being dependent on these technologies (e.g. GNSS, radio communication) through a disturbed ionosphere but also through sector-specific vulnerabilities. For example, Atkins has recently undertaken a study in relation to rail infrastructure, which has specific communication technologies and signal networks that are vulnerable to space weather. Therefore there is a need to consider sector vulnerability in more detail and this is particularly important for critical national infrastructure. Whilst much of this infrastructure has been examined, water is an area which merits increased attention. The water sector has extensive metal pipeline networks and is increasingly dependent on remote information collection and real-time control. The last two years of drought and extensive inland and coastal flooding has demonstrated the importance of effectively managing water. Moreover, the water sector uses UHF radio communication as an integral part of their operations and infrastructure. Since space weather is able to influence the propagation of signals through the modification and disturbing of the Earth's ionosphere, this represents an indirect way by which space weather can adversely influence the water sector operations and infrastructure. Atkins is the main stakeholder for this work, and Atkins is currently liaising with major water company clients on this issue. The wider stakeholder sphere will include the Environment Agency (as an asset manager and regulator), Ofwat, the Drinking Water Inspectorate, all water companies and water company supplies including consultants and the asset supply chain.

High-speed rail lines, at ever increasing speeds and distances, are in development both in the UK and world-wide, but up-front capital expenditure can potentially be a major inhibiting factor both to the client and also in the eyes of the public. Cost reductions for these lines could be achievable if the initial costs of the physical construction, the duration of construction and the land take could be reduced. All three of these costs can potentially be reduced for embankments if the industry were to move towards a novel embankment replacement system. In addition embankment replacement systems could significantly improve the performance of the track structure as the dynamic properties of the contained material can be better controlled. However, such technology requires significant performance evaluation and the development of appropriate design guidance before UK industry can justifiably implement it in a project. This project therefore aims to evaluate and produce design guidance for two novel embankment replacement systems as a means to potentially reduce the cost of constructing new high-speed railway lines (particularly in urban environments) and improve the overall track behaviour and hence passenger experience.

Cement manufacture accounts for about 5% of global carbon dioxide emissions, the single largest contribution of any man-made material. Despite this, research has shown that concrete is generally inefficiently used in the built environment. This fellowship will look to reduce the global environmental impact of concrete construction through a new method for the analysis of reinforced concrete structures that is well suited to producing the optimised designs that have the potential to significantly reduce material consumption. The new analysis method will be considered alongside practical construction processes, building on previous work by Dr Orr in this field, thus ensuring that the computationally optimised form can actually be built, and the research adopted, in industry. Most existing computational methods poorly predict the real behaviour of concrete structures, because their underlying mathematics assumes that the structure being analysed remains continuous as it deforms, yet a fundamental property of concrete is that it cracks (i.e. it does not remain continuous as it deforms). In contrast to finite element methods, this fellowship will develop a meshfree analysis process for concrete based on 'peridynamics'. The term 'peridynamic' (from 'near' and 'force') was coined by Dr Silling (see also statements of support) to describe meshfree analysis methods in solids. This new approach does not presume a continuous displacement field and instead models solid materials as a collection of particles held together by tiny forces, the value of which is a function of each particle's relative position. Displacement of a particle follows Newton's laws of motion, and is well suited to reinforced concrete since: 1) concrete really is a random arrangement of cement and aggregate particles; 2) failure is governed by tensile strain criteria, which is ideal as the only real way that concrete fails is in tension (all other failure modes in everyday design situations are a consequence of tensile failure) and the model can therefore accurately predict behaviour, and 3) since the elements fail progressively in tension, the peridynamic approach automatically models cracking behaviour, which is extremely difficult to model conventionally. A variety of force-displacement relationships can be defined to model the concrete, the reinforcement, and the reinforcement-concrete bond that together define the overall material response. The approach models the material as a massively redundant three-dimensional truss in which the randomly arranged particles are interconnected by elements of varying length. Although an optimal 'element density' has not yet been determined (see Section 2.4.1 in the case for support) proof of concept work has used tens of millions of particles and hundreds of millions of elements per cubic metre of concrete. From the simple rules and properties applied to these elements, all the complex behaviour of concrete can be predicted. Individual element definitions will be determined by laboratory tests and computational analysis, with both historic and new test data utilised. Crucially, the model has been shown in proof-of-concept work to be able to predict the cracking behaviour of concrete, overcoming a key computational challenge. Optimisation routines, in which material is placed only where it is needed, will then be integrated with the new analysis model to design low-carbon concrete structures. Consideration of the practical construction methods will also be given, building on previous work in this area by Dr Orr. The designs that result from such optimisation processes will have unconventional but completely buildable geometries (as evidenced in Dr Orr's previous work) - making them ideal for analysis using the proposed random elements approach.

The United Kingdom has rapidly ageing civil infrastructure. The ability to re-use deep foundation systems and construct new ones more efficiently will pave the way for considerable savings in financial and carbon resources. Geotechnical engineers frequently rely on past records and experience to design foundations. Foundation performance in the stiff deposits in the UK is difficult to estimate and is often reliant on preliminary pile tests to failure being available. If these tests are not available then very conservative design assumptions are used. This research project will provide the UK geotechnical community with an openly accessible database of pile load tests in UK soil deposits. Much of the data for the database will be sourced from the literature and consultants' records. Using the database, different models that can be used to predict pile settlement response will be compared statistically and re-calibrated. Estimates of 'reserve capacity' in UK foundation systems will also be made to search for insights into the potential for foundation re-use in future construction projects. The results of the analysis can also be used to derive improved partial factors for pile design. These can be used in new and updated codes of practice and design guides. A user friendly web-portal will be developed so that designers and researchers can rapidly access the underlying datasets in the database. This will allow others to calibrate their own models for pile behaviour.

In the UK and globally, the slope failures of various sizes are crucially affecting the sustainable development of resilient cities, as its occurrence can significantly threaten the populations, infrastructures, public services, and environment. For example, the British Geological Survey has estimated that 10% of slopes in the UK are classified as at moderate to significant landslide risk, with more than 7% of the main transport networks located in these areas. These slopes may fail during prolonged periods of wet weather or more intensive short duration rainfall events. To date, the public awareness of slope failure risk is high, but our understanding of its fundamental failure mechanism and countermeasures are still very limited. This is mainly due to the difficulties in analysing the multiscale responses and characterize the spatial inhomogeneity of material properties of slopes. Laboratory and numerical investigations with well-developed empirical models can explain the general features of some specific slope failure events but cannot be applied universally. Some challenging issues need to be addressed, such as i) How to develop reliable mathematical models with multiscale modelling capability to analyse the progressive failure of slopes? ii) How to address the spatial variabilities and uncertainties of real slopes, e.g. material property, fractures, fluid permeability? iii) How to accurately estimate the spreading of landslide and its impact on infrastructures? The fundamental scientific issue of these challenges is the weakening mechanism of inhomogeneous slopes at different scales as it determines the slope responses under various geological and environmental conditions. The proposed research aims to explore the fundamental mechanism of progressive slope failure and its impacts on infrastructures via a multiscale and probabilistic modelling approach. It enables the large deformation of slopes to be conveniently analysed by FEM as boundary value problem (BVP), while the local fracturing, cracking, or discontinuous behaviours of soil to be evaluated in smaller discrete subdomains through granular mechanics by DEM. The boundary condition of DEM assembly is derived from the global deformation of FEM meshes. In the analysis, the soil/rock properties (e.g. elastic modulus, friction coefficient, strength, and fluid permeability) will be evaluated as random fields with spatial variabilities. The numerical modelling can effectively bridge the gap between the microscopic material properties and the overall macroscopic slope responses. In the numerical modelling, the contributions of material inhomogeneity and discontinuity to slope failure and subsequence landslide spreading can be effectively investigated. The internal fracture would occur naturally when the loading stress exceeds the particle bonding strength at the microscale, which avoids the use of some phenomenological constitutive laws in conventional continuum modelling. As a multidisciplinary research, this project will involve the subjects of geotechnical engineering, computational geotechnics, geology, statistics, soil/rock mechanics and granular mechanics. The proposed numerical model will benefit all researchers and stakeholders in land planning and management by providing efficient and reliable numerical modelling approaches. This will support the landslide risk evaluation, hazard mitigation and long-term land management, from which the environmental, social, and economic benefits can be achieved. As a result, the decision makers would have greater confidence in slope failure risk assessments on which they are basing their infrastructure investment considerations. Consequently, hazard warning systems, protections and land utilization regulations can be implemented, so that the loss of lives and properties can be minimized without investing in long-term, costly projects of ground stabilization.