FOCUS: Intelligent Fibre Optic Monitoring to Inform the Construction of Underground Services

Lead Research Organisation: University of Oxford
Department Name: Engineering Science

Abstract

UK construction is a multi-billion pound industry. While it is the most vital cog in the UK economy for creating physical assets, it is widely regarded as slow to innovate. High risks and the significant cost of mistakes promotes a level of conservatism which is much greater compared to other industries. Change therefore tends to be iterative and cautious. Supported by the UK Government through the implementation of various construction initiatives, such as 'Construction 2025' and 'Transforming Construction', the industry is beginning to embrace technology in a transformative way. The technological revolution is already under way for 'above-ground' construction activities, with modular construction and building information modelling being primary examples. One of the biggest obstacles to underground construction making similar gains is uncertainty surrounding how structures interact with soils during construction operations i.e. 'soil-structure interaction' (SSI). Soil-structure interaction plays a critical role in underground construction operations yet the tools that are used to predict them remain remarkably over-conservative. This is because predictive models for SSI are non-existent, over-simplified or are calibrated against measured data obtained from model-scale replicas of the process in the laboratory, essentially representing an 'ideal' soil-structure interface.

The work described in this proposal will develop the underpinning engineering science for SSI design applied to underground construction. Laboratory testing and numerical modelling will be used to elucidate the mechanics of soil-structure interface behaviour such as the role of strain level, stress level and time on the development of soil-structure contact stresses and pore water pressures. Intelligent monitoring systems will be developed to measure and monitor soil-structure contact stresses on live construction projects to provide (i) field data for rigorous validation of developed design methods and (ii) real-time, automated feedback to site engineers to inform construction processes and provide 'early warning' of adverse responses. Recent advances in fibre optic sensing will be exploited to develop novel multi-directional contact stress sensors. The new sensors will alleviate limitations associated with traditional transducers such as excessive sensor flexibility (which actually influences the soil stress field the sensors are intended to measure) and immunity to electromagnetic noise and water damage. A multi-directional interface shear apparatus will be developed to validate the contact stress sensors and provide additional insight into the behaviour of an 'ideal' soil-structure interface in the laboratory. The monitoring system will employ machine learning algorithms in the form of Bayesian non-parametrics such that prior data from previous construction projects may be synthesised with newly-acquired data to provide a robust data-driven decision-making process. The monitoring system will be deployed on live construction projects in the UK alongside industry partners. A suite of new design methods tailored specifically for underground construction operations will be developed, informed by the field monitoring, laboratory testing and numerical modelling. Embracing the innovation and technology developed in this project will allow the construction industry to obtain and utilise intelligent and actionable data that can save time and money, and improve construction safety. This will contribute to the UK becoming a global hub for the rapidly growing market for construction-related services throughout the world.

Planned Impact

The potential to translate research outcomes into economical, societal, and environmental benefits are very substantial. The construction industry would benefit significantly from the proposed SSI design methods and monitoring systems. These methods and systems will reduce the uncertainty associated with soil-structure interaction during underground construction, leading to improved project outcomes. For example a build-up of soil-structure interface friction will be identified early on in projects, thereby allowing preventative action to be taken, avoiding work stoppages and project delays. The development of an underground construction research group at Oxford will also produce the next generation of construction professionals to revitalise the industry.
The public sector will benefit from this research because a reduction in underground construction risks are associated with lower construction costs as a result of reduced contingency in project budgets and more reliable project timelines. Construction activity is one of the cornerstones of the UK's economy and contributes significantly to economic growth. It reflects dynamic growth in other industries and is itself a core provider of jobs. Beyond the construction activity itself, construction also drives demand for various building materials. Often perceived as being behind the curve, it is critical that the construction industry embraces innovative technology to guarantee UK prosperity.
The PI will also personally benefit as the research leader of FOCUS by further developing his skills and expanding his research team. The research team will benefit from the valuable training in state-of-the-art facilities offered by the industry partners. They will also benefit from a number of career development opportunities including outreach events and a very wide range of courses run by the Mathematics and Physical Life Sciences Division at Oxford. In the long-term, the PI intends to integrate 'Construction Engineering' into the undergraduate curriculum which is, perhaps surprisingly, not currently taught at Oxford. The Oxford engineering undergraduates will therefore also benefit from both a new course and the inclusion of cutting-edge research being conducted by the PI's group.
The construction industry is the single largest global consumer of resources and raw materials, so even a 1% reduction in construction costs would save society huge sums globally. Value therefore lies in improving construction practice, leading to efficiency gains and reduced consumption of materials. Society as a whole will experience a major benefit from significant reductions in CO2 emissions on planned construction projects. Driving down both the economic and environmental costs of construction will boost the resilience of the UK infrastructure sector.
The construction industry is generally perceived by the public as an old-fashioned, wasteful and male-dominated industry which has, in part, contributed to a major skills shortage in the UK construction sector. Attracting young engineers and tradespeople into construction has become increasingly challenging. Inevitable retirements of experienced UK construction personnel means the UK skills shortage is likely to worsen. The public engagement / outreach activities outlined in 'Pathways to Impact' will increase public awareness of modern underground construction practice. They will also highlight the huge variety of construction related careers. For the industry to begin appealing to those who currently view it as very static, it is crucial that young people are made of aware of these opportunities and developments.

Publications

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Sheil B (2020) Machine learning to inform tunnelling operations: recent advances and future trends in Proceedings of the Institution of Civil Engineers - Smart Infrastructure and Construction

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Sheil B (2022) Bearing capacity of open caissons embedded in sand in Géotechnique

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Sheil B (2022) Prediction of Pipe-Jacking Forces Using a Bayesian Updating Approach in Journal of Geotechnical and Geoenvironmental Engineering

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Templeman J (2021) Cutting shoe design for open caissons in sand: influence on vertical bearing capacity in Proceedings of the Institution of Civil Engineers - Geotechnical Engineering

 
Description One of the key objectives of this research grant was the development of a novel sensor to be able to measure soil contact stresses exerted on underground structures. This has now been achieved and is currently being commercialised in the form of a spinout company.

The second objective was to develop holistic real-time monitoring systems to inform underground construction processes. This has also been achieved and our research has shown that timely feedback of key information on site can have a significant influence on the safety and efficiency of construction operations.
Exploitation Route The main pathway to impact for our research is through the strong industry network established for this grant. We will use these connections to convince key industry players to take up the new sensing technologies and monitoring systems. Commercialisation of the sensing technology is also being pursued to achieve more widespread take-up.
Sectors Construction

URL http://oxfocus.co.uk/
 
Description New design methods that have been developed for this research have been used for the design and construction of two major water and wastewater projects in Ireland, specifically in Blanchardstown and Arklow (includes microtunnelling and large diameter caisson shafts). The arklow wastewater treatment plant also made use of the new sensing and monitoring systems developed by our research team to inform the construction processes
First Year Of Impact 2021
Sector Construction
Impact Types Societal,Economic

 
Description EPSRC Impact Acceleration Account
Amount £71,500 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 01/2021 
End 12/2021
 
Description NERVE: Novel embedded and robust optoelectronics to value engineer precast manufacturing
Amount £62,500 (GBP)
Organisation University of Southampton 
Department Future Photnics Hub
Sector Academic/University
Country United Kingdom
Start 11/2021 
End 07/2022
 
Description Royal Academy of Engineering Proof of Concept Scheme
Amount £49,700 (GBP)
Funding ID PoC2021\20 
Organisation Royal Academy of Engineering 
Sector Charity/Non Profit
Country United Kingdom
Start 01/2021 
End 12/2021
 
Description Royal Commission for the Exhibition of 1851 Industrial Fellowship
Amount £95,500 (GBP)
Organisation Royal Commission for the Exhibition of 1851 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2020 
End 10/2023
 
Description iDRIVE: Intelligent driveability forecasting for offshore wind turbine monopile foundations.
Amount £125,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Department Supergen
Sector Public
Country United Kingdom
Start 09/2021 
End 09/2022
 
Description Inside concrete - Cambridge University 
Organisation University of Cambridge
Country United Kingdom 
Sector Academic/University 
PI Contribution This collaboration led to a successful application to internal funding at Cambridge to provide a one year postdoctoral researcher to work on fibre optic monitoring of underground concrete structures. I provided guidance and advice on the fibre optic monitoring and the expected loads experienced by buried underground structures (e.g. tunnels).
Collaborator Contribution University of Cambridge provided funding for a one year postdoctoral researcher. Professor Janet Lees at University of Cambridge provided her expertise and access to state of the art equipment and testing facilities for the development of concrete test specimens. Professor Martynas Beresna provided expertise on optical fibres and optical interrogators.
Impact This collaboration is on-going so there is no outputs yet
Start Year 2020
 
Description Inside concrete - Cambridge University 
Organisation University of Southampton
Country United Kingdom 
Sector Academic/University 
PI Contribution This collaboration led to a successful application to internal funding at Cambridge to provide a one year postdoctoral researcher to work on fibre optic monitoring of underground concrete structures. I provided guidance and advice on the fibre optic monitoring and the expected loads experienced by buried underground structures (e.g. tunnels).
Collaborator Contribution University of Cambridge provided funding for a one year postdoctoral researcher. Professor Janet Lees at University of Cambridge provided her expertise and access to state of the art equipment and testing facilities for the development of concrete test specimens. Professor Martynas Beresna provided expertise on optical fibres and optical interrogators.
Impact This collaboration is on-going so there is no outputs yet
Start Year 2020
 
Description Low-cost optical strain sensing 
Organisation University of Southampton
Country United Kingdom 
Sector Academic/University 
PI Contribution We have provided expert on how strain sensing might be used in civil infrastructure sensing to back analyse parameters of interest such as applied forces. This has included a combination of numerical analysis, laboratory testing and machine learning
Collaborator Contribution Southampton have been working on the development of a novel low-cost FBG interrogator to achieve a step change in FBG sensing
Impact This work is still in progress. Initial progress has formed the basis for commercialisation of our research in the form of a spinout company: Jenkin Technologies Ltd
Start Year 2021
 
Description ML to inform tunnelling 
Organisation Colorado School of Mines
Country United States 
Sector Academic/University 
PI Contribution This was a collaboration to review the state of the art in machine learning to inform tunnelling operations. This involved my expertise and intellectual input and I wrote a co-authored journal paper which summarised this work
Collaborator Contribution Professor Michael Mooney (Colorado School of Mines) and Professor Hehua Zhu (Tongji University) provided their expertise and intellectual input
Impact An output of this collaboration was a co-authored journal paper
Start Year 2020
 
Description ML to inform tunnelling 
Organisation Tongji University
Country China 
Sector Academic/University 
PI Contribution This was a collaboration to review the state of the art in machine learning to inform tunnelling operations. This involved my expertise and intellectual input and I wrote a co-authored journal paper which summarised this work
Collaborator Contribution Professor Michael Mooney (Colorado School of Mines) and Professor Hehua Zhu (Tongji University) provided their expertise and intellectual input
Impact An output of this collaboration was a co-authored journal paper
Start Year 2020
 
Description Monitoring from Space - Satellite Applications Catapult 
Organisation Satellite Applications Catapult
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution I am supervising an employee of the Satellite Applications Catapult (Ms Maral Bayaraa) as a doctoral student at Oxford. I provide expert advice and training on geotechnical and numerical modelling for the prediction of tailings dam collapse for the mining industry.
Collaborator Contribution This collaboration involved an application for an 1851 industrial Fellowship which involved a part contribution from the Satellite Applications Catapult. The awarded doctoral student is co-supervised by one of the principals at the company who provides expert advice on satellite monitoring techniques.
Impact This collaboration has only recently started so there are no outputs or outcomes to list yet.
Start Year 2020
 
Description Strain sensing using optical frequency combs 
Organisation Aston University
Country United Kingdom 
Sector Academic/University 
PI Contribution we have been providing specialist expertise and laboratory equipment for high-precision strain and temperature sensing for underground construction applciations
Collaborator Contribution the aston team have been developing a completely novel approach involving the use of optical frequency combs to measure strain and temperature independently
Impact This collaboration has just started. We have submitted an EPSRC grant application
Start Year 2022
 
Description Website development 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact We have developed a website to promote our research to the general public and to promote our research to industry to maximise the chances of industry take-up of our monitoring systems. I advertise this website at all talks I give and my email signatures
Year(s) Of Engagement Activity 2020
URL http://oxfocus.co.uk