Smart Bridges

Fibre optics that give remote and real-time assessment of structural health.

Last updated: 5th January 2022

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Innovation Lead: Dr Jennifer Schooling

Website:
www-smartinfrastructure.eng.cam.ac.uk/


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Summary

The Centre for Smart Infrastructure and Construction (CSIC) has created two of the first ever smart bridges in the UK. Fibre optic sensors monitor everything about the bridge's performance throughout its entire life, from manufacture and construction to operation and maintenance. These two new smart bridges are more than just passive masses of concrete and steel – they act as self-sensing structures that will update asset managers and engineers of their changing condition. They will create a real-time picture of the bridge's performance so maintenance can be scheduled when and where needed, rather than relying solely on infrequent visual inspections that can be prone to error, hazardous and costly. And because this level of monitoring is unprecedented, it acts as a living lab to capture insights that could change the future design of our bridges, and create a smart infrastructure that better supports the services it delivers and the people who use it.

Innovation type: Digital
Organisation type: Construction tier 1 contractors, Private sector client, Research centre

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Project pioneers

The Centre for Smart Infrastructure and Construction (CSIC) is an Innovation and Knowledge Centre (IKC) funded by Innovate UK and EPSRC. It is hosted at the National Research Facility for Infrastructure Sensing (NRFIS) at the University of Cambridge, along with the Laing O’Rourke Centre for Construction Engineering and Technology (LORC). Together they accelerate industry adoption of sustainable smart infrastructure solutions.

The problem

Bridges are critical, complex structures that connect communities and form a key part of our national infrastructure. Many UK bridges are ageing and nearing the end of their service life, carrying significantly more vehicles than originally expected and exposed to harsh environmental conditions due to the effects of climate change. Maintenance and repairs can be costly. According to an annual survey by RAC Foundation and ADEPT the one-off cost of the maintenance backlog for 71,505 council-managed road bridges in Britain is £5.55 billion. Bridges have hard-to-see details making them difficult to inspect. Current practice relies on periodic visual inspections which are qualitative, laborious and costly and often fail to estimate the true strength reserve of bridges. Inspections near busy roads or railways, at height or over water bring additional risk and require protective equipment and apparatus such as mobile elevating work platforms. These manual approaches are often infrequent and inefficient and can lead to costly repairs, disruption to transport networks or even loss of life.

Vision

Creating smart bridges with fibre optic monitoring systems starts to show what is possible for remote, real-time condition assessment over the lifetime of a structure. The high levels of data they produce gives owners and operators a more accurate picture of the condition and structural health of our bridges and the effects of the environment around them - without the costs and hazards associated with on site visual inspections. Asset managers can then schedule timely maintenance and make better informed operational decisions. The more robust and reliable data can then lead to more efficient and effective asset management plans across the industry which ultimately improve the whole-life value of our bridges - letting our infrastructure do what it does best and connecting people and places without disruption.

Key Insight

With increasing levels of passengers and freight, the West Coast Main Line was set to reach capacity in the next decade. To mitigate this, the Stafford Area Improvement Programme in 2014 led to the formation of The Staffordshire Alliance to deliver improvements. This major upgrade involved, among other things, the construction of 10 new bridges which created an opportunity to test new methods and technologies to monitor the structural performance of the bridges and improve the way bridges are maintained and designed in the future. 

First step

As leading experts in fibre optic sensing and data analysis, the Centre for Smart Infrastructure and Construction (CSIC) was brought on board to embed monitoring instruments into two of the 10 bridges. These intelligent bridges and the innovative data analytics and modelling programmes that followed created a living lab that could capture unprecedented insights and understanding of the whole-life performance of these assets.

Barrier

Traditional visual inspections to inform repair and maintenance programmes for bridges are limited. As well as being prone to human error, they only support a short-term, periodic picture of the structure which limits the possibility of proactive maintenance schedules. This snapshot can result in unseen costs and delays further down the line. Longer-term, detailed and continuous data about a structure will transform these traditional approaches to proactive condition monitoring and predictive maintenance. But the industry needs evidence-based case studies to demonstrate value and build confidence in change.

Process innovation

The structural configurations of the two monitored bridges are common types that exist on the UK transport network; one is a precast prestressed concrete bridge with cast-in-situ concrete infill deck slab and the other is a composite bridge with steel girders and cast-in-situ reinforced concrete deck slab. The fibre optic sensor cables were installed into the prestressed concrete beams offsite at Laing O'Rourke's Explore Manufacturing facility to enable faster installation of the densely instrumented monitoring systems that will measure the whole-life performance of the bridges. Instrumented modular elements enabled sensors to acquire data on the manufacturing process itself and on the integrity of the components during transportation and installation. Measurements taken at the critical construction stages allowed tracking structural response and comparison against nominal design values.

Digital Innovation

CSIC is working with data scientists at the Lloyds Register Foundation, the Alan Turing Institute Data-centric Engineering Programme (The Turing) and data scientists from the Department of Mathematics at Imperial College London. They are developing innovative analysis systems to process the reams of continuously-collected data, captured by two types of fibre optic monitoring systems (one a Brillouin Optical Time Domain Reflectometry and the other a point-based system using fibre Bragg gratings) that measure changes in thermal strain in real time. This real time data is stored securely on a BIM model in the cloud system, using Microsoft Azure, so the data scientists at The Turing can perform high level integrated data analytics, which are then assessed and modelled by structural engineers at Cambridge. The data gathered provides a rich source of information – each bridge has the potential to generate up to 12GB data per day. Part of this project will be to identify which of the data collected are important to retain and which can be discarded, developing automated techniques for culling unimportant data. The important data will be interpreted using integrated algorithms to provide additional insights into the site-specific conditions. Based on the data collected so far, the CSIC team is witnessing structural behaviour that has previously not been captured, such as the real-time dependent behaviour of pre-stressed concrete girders and sleepers; the development of thermal and concrete shrinkage strains in bridge decks; and the effect of staged construction traffic on the overall bridge response. Digital twin models of the bridges – the live digital representation of the physical assets – will help simulate various 'what if?' scenarios around the damage or deterioration of the bridge. Owners can then make accurately-informed decisions whether to decommission or repair, potentially extending the life of the bridges. The data and insights will also support better outcomes for our national infrastructure and has the potential to transform the structural health monitoring and asset management, and inform future design to better address zero carbon, resource constraint and resilience.

Whole life innovation

These intelligent bridges are the first of their kind. Faced with an increased demand on our transport infrastructure and more extreme weather events, this integrated monitoring system gives a better understanding of the real performance of structures in the UK. The whole-life structural health passport that the data delivers helps clients compare structural behaviour measurements to visual inspections and design expectations. So rather than replace visual inspections, the data will enhance them and make maintenance more efficient and effective. Insights from the data analysis will also optimise future designs of similar assets, creating a closed loop asset life cycle. Looking to the future, as part of the UK’s National Digital Twin programme, digital twins connected across the rail network will unlock value for all stakeholders and support better outcomes for services delivered by infrastructure for society.

Collaborators

CSIC is an Innovation Knowledge Centre (IKC) funded by Innovate UK and the Engineering and Physical Sciences Council (EPSRC), and hosted at the National Research Facility for Infrastructure Sensing (NRFIS) at the University of Cambridge. It is a founding partner of the UK Collaboratorium for Research on Infrastructure and Cities (UKCRIC) and collaborates with partners to accelerate industry adoption of sustainable smart infrastructure solutions. The Laing O’Rourke Centre for Construction Engineering and Technology (LORC) is also based at Cambridge University and aims to transform the construction industry through innovation, education and technology. Together they were invited to work with the Staffordshire Alliance, a collaboration between Atkins, Laing O'Rourke, Volker Rail and Network Rail. CSIC industry partner Network Rail, provided access to the bridges to install the equipment and funded the installation of power supplies to the sensing equipment and the provision of ongoing power. Network Rail continues to support CSIC’s research work on the smart bridges.  CSIC works with Lloyds Register Foundation and the Alan Turing Institute (The Turing) and data scientists from the Department of Mathematics at Imperial College London to design and deploy the long-term mixed-sensor monitoring systems.

  • Atkins
  • Centre for Smart Infrastructure and Construction (CSIC)
  • Department of Mathematics at Imperial College London
  • Laing O'Rourke
  • Lloyds Register Foundation
  • Microsoft
  • Network Rail
  • The Alan Turing Institute
  • Volker Rail

Lead support

Core funding from Innovate UK and EPSRC helped to establish CSIC as an Innovation Knowledge Centre (IKC) specialising in cutting edge sensing and data analysis models. Additional funding from the Centre for Digital Built Britain, part of the Construction Innovation Hub, has allowed CSIC researchers to continue work on the smart bridges to deliver real time data analytics and digital twin models that will enable better decision-making for asset management.

Long Term Vision

The creation of smart infrastructure will give owners and operators the greatest confidence in their decisions around the management, maintenance and repair of critical assets. The high volumes of data will improve understanding of the condition and structural health of these bridges and the effects of the environment around them. The whole-life structural health passport stays with the structure even if the asset owner or manager changes, and can be used to inform more sustainable future design. Continuous data also helps identify a baseline for assessing long term behaviour and establishing trends. Looking to the future, as part of the National Digital Twin programme, digital twins connected across the rail network will unlock value for all stakeholders and support better outcomes for services delivered by infrastructure for society. More robust and reliable data can lead to more efficient and effective asset management decision-making which ultimately improves the whole-life value of our bridges and structures – letting transport infrastructure do what it does best and connecting people and places without disruption.

Human Stories

Collaboration between academic researchers and industry has led to delivery of the most comprehensively instrumented new rail bridges in the UK. The monitoring systems improve the safety of surveyors and asset managers as they reduce the need for manual, visual inspections that can be hazardous, especially if bridges are in hard to reach places that are difficult to inspect. The huge volumes of data captured from these smart bridges help simulate various 'what if?' scenarios around the damage or deterioration of the bridges, helping improve the safety and integrity of the structures and services they deliver.

Powerful Processes

Offsite manufacturing processes at Laing O'Rourke's Explore Manufacturing facility were used to install the fibre optic sensor cables into the main prestressed beams, steel girders and concrete sleepers, aiding faster installation. The sensors then gather data on the manufacturing process itself and the integrity of the components during transportation and installation. The data and advanced data analysis helps engineers and statisticians, and asset owners and managers, assess the performance of the bridges with greater accuracy and frequency. Going forward, the data is being used to create a digital twin model of the bridges. Digital twin models of the bridges – the live digital representation of the physical assets – help simulate 'what if?' scenarios around the damage or deterioration of the bridge so asset owners can decide whether to decommission or repair, potentially extending the life of the bridges.

Fascinating Facts

The data gathered provides a rich source of information - each bridge has the potential to generate up to 12GB data per day.

Benefits

Safety
Providing long term performance monitoring using fibre optic sensors will present a far lower health and safety risk than visual inspection of bridges, especially for those structures in hard-to-access locations. The accuracy of the data sent from the monitoring systems will help identify damage and deterioration and lead to more proactive repair and maintenance programmes. In the long term, this will improve the whole-life resilience, performance and integrity of the structure.

Whole-life Value
The whole-life monitoring of these Staffordshire bridges will provide data to inform future design, construction, operation and maintenance of bridges and wider infrastructure. Looking to the future, as part of the National Digital Twin programme, digital twins connected across the rail network will unlock value for all stakeholders and support better outcomes for the UK's infrastructure. Asset owners can decide whether to decommission an asset based on information acquired from measured data or repair and maintain it, potentially extending the life of the bridges.