The UK uses around 50 GW of energy to heat and cool buildings with only 6% delivered from renewable sources. Heating of buildings represents almost a quarter of UK carbon emissions, while demand for cooling is projected to increase as the climate warms and summers become hotter. The UK Heat and Buildings Strategy is clear that action to reduce emissions is required now to facilitate compliance with legally binding 2050 Net Zero targets. Moreover, the current geopolitical uncertainty has highlighted the risks associated with importing energy. However, heat is challenging to decarbonise due to its extreme seasonality. Daily heat demand ranges from around 15 to 150 GW, so new green technologies for inter-seasonal storage are essential. Geothermal resources offer natural heat energy, very large-scale seasonal energy storage, cooling as well as heating, and steady, low carbon energy supply. Widespread exploitation of urban geothermal resources could deliver a significant component - and in some cases all - of the UK's heating and cooling demand, supporting UK self-sufficiency and energy security. However, barriers remain to uptake of geothermal energy, especially at large-scale in urban areas. There is uncertainty in the size of the underground resource, the long-term sustainability of urban geothermal deployments, and potential environmental impacts. New methods and tools are required to monitor and manage installations to ensure the resource is responsibly used. These knowledge gaps, along with lack of awareness and guidance available for stakeholders and decision makers, result in higher than necessary risks and therefore costs. In this project, we will remove obstacles to uptake by reducing uncertainty about how the ground behaves when used to store and produce heat and cool at a large scale in urban areas. We will focus on relatively shallow (<400m depth) geothermal resources and open-loop systems in which groundwater is pumped into and out of porous, permeable aquifer rocks underground, because these offer large storage capacity and can deliver heat and cool. Shallow, open-loop systems are also deployable in most UK urban areas and have lower investment costs than technologies which require deeper drilling. We will conduct advanced field experiments with state-of-the-art monitoring, supported by laboratory experiments, to determine the response of aquifers to storage and exploitation of heat and use the results to understand how temperature changes over a wide area as groundwater flow transfers heat within the aquifer. We will compare two different aquifers, with contrasting types of underground flow regimes, that can be exploited across much of the UK. We will also determine how temperature changes impact groundwater quality and stress ecological environments and sensitive receptors, as well as understand any risks of ground movement caused by use of the resource. The field data will be used to create calibrated heat flow models, which we can use as a 'numerical laboratory' to simulate and explore the capacity of urban geothermal and how different installations within a city might interact. The results will support planning of future resource use and assess the capacity of geothermal resources to store waste heat from industrial processes and commercial buildings and return it later when needed. We will explore the use of AI-based models that can 'learn' from data provided by geothermal operators to actively manage the resource in a responsible and integrated way. Together, this research will permit regulators to plan and permit installations to ensure fairness and prevent environmental damage, as well as ensuring system designs realistically predict the amount of energy available. Recommendations will be made for resource assessment, safe and sustainable operation and management, to stimulate the widespread development of low carbon, geothermally heated and cooled cities.

Recent years have seen an explosion in the number of large-scale structures such as tall buildings and long span roofs (e.g. all but one of the world's 20 tallest buildings was constructed in the last 15 years, almost all of which are over 400m in height; furthermore, it has recently been estimated that 4 million skyscrapers of 40 stories will be required by 2050 to accommodate worldwide urban population growth). However, currently the forms of such structures are usually identified in an ad-hoc manner, with very limited application of optimization techniques, despite the fact that such techniques are now routinely used in other industrial sectors (e.g. automotive and aerospace). This means that material consumption and associated greenhouse gas emissions will often be far higher than necessary, and novel structural configurations which permit inclusion of energy efficient features such as light wells or atriums will often be overlooked. In this project highly efficient mathematical optimization methods will be developed specifically for large-scale building structures, and used to automatically identify efficient layouts of structural elements. This will enable determination of the 'absolute minimum material reference design' for a given design brief, providing a powerful new means of evaluating the relative efficiency of alternative structural layouts. Methods will also be developed to automatically generate simpler and more practical structural layouts, which consume little more material than the absolute minimum quantity. The methods will be used to identify structurally efficient layouts for a range of applications, including tall building exoskeleton design and long-span canopy roof design. Considering tall buildings, a recent development has been the use of exoskeleton 'diagrids', which give a clear expression of the structural system, and are perceived to be more efficient than conventional solutions. However, the use of any predefined configuration will implicitly inhibit efficiency and vast numbers of alternative layouts will be able to be considered using the tools to be developed in this project. Considering long-span canopy roofs, such as those used in sports stadia, exhibition halls and factories, reducing material consumption by adopting a more efficient layout of elements leads to a 'virtuous circle' since as structural self-weight is reduced, so does the amount of structural material required to support this. The project will result in the development of practical tools and guidance for practitioners, and educational materials for students. Successful delivery of the research can be expected to dramatically improve the ability of engineers to design structurally efficient large-scale buildings.

Explosions are a pressing and pervading threat in the modern world. Terrorist events such as the 2017 Manchester Arena bombing, large-scale industrial accidents such as the 2020 Beirut explosion, and the current conflict in Ukraine, have highlighted a key gap in our knowledge: we do not we do not yet understand how blast waves propagate and interact with multiple obstacles in complex environments. Accordingly, we cannot yet predict the loading from such events, and our ability to determine the consequences relating to risk, structural damage, and casualty numbers, is severely limited. Current numerical tools for predicting blast loads in complex environments are either overly simplistic, or physics-based numerical tools which have been hitherto developed in the absence of experimental validation data. Clearly, progress in this area is limited and will remain so until we have the ability to experimentally measure the output from explosions occurring in settings of varying complexity at varying scales. This proposal will see the development of an ambitious and unique experimental facility, MicroBlast, for ultra-small-scale studies of blast propagation in complex environments, making use of rapid prototyping and 3D printing to generate true replica test specimens. MicroBlast will be a new state-of-the-art apparatus for data-rich, high spatial/temporal resolution, multi-parameter, full-field measurements of blast loading using a combination of pressure sensors, stereo high speed video cameras, and medium-wave infra-red cameras. This facility will be a step-change in our ability to perform rapid, precision experiments in explosive load quantification; the blast equivalent of a wind tunnel or shaking table test. We aim to study the fundamental mechanisms governing blast load development in complex environments, and set the agenda for future research in this area. Are explosions in crowded environments repeatable and deterministic, or are they highly sensitive to small changes in input parameters? What are the consequences for numerical modelling tools and experimental design? We aim to develop the next generation of predictive approaches for blast in urban environments, and to collectively raise the scientific benchmark of load prediction and structural damage assessment.