Structural Health Monitoring in civil engineering
Peter Sparkes, AECOM Associate director and co-author of CIRIA guide C788 outlines the importance of monitoring as demands on our infrastructure increase and change.
Covid-19 has given us a temporary glimpse of how attractive the world would be with fewer vehicles and cleaner air. This has stimulated ideas and plans for a different transportation culture, working to hold on longer to the gains we have seen and felt. There are now more options to examine for the direction of our transportation future. In all cases our existing infrastructure will remain to be used to its capacity. Therefore knowing its capacity during its life is essential.
In the House of Lords debate on Post Covid-19 strategies on June 11th 2020, Lord Mair, Head of CSIC (Cambridge Centre for Smart Infrastructure and Construction) extolled that we should “optimize the assets that we already have by measuring and understanding their performance. We should fix them before rushing to build new infrastructure.” He also stated that “all the new infrastructure that we build must be cost-effective and resilient. Covid-19 has forced rapid changes in practice on our society”.
The new CIRIA guide C788 Structural Health Monitoring (SHM) in civil engineering aims to address the increasing importance of knowing more about infrastructure, old and new, to extend its life. If we know more, we can reduce risk and we can make better decisions. We can direct our financial resources with more confidence that it will be money well spent. With appropriate technology we can monitor in real time, and enable our assets to be smart, to inform us of their condition. Many of our mobile phones already contain monitoring devices commonly used in civil engineering – accelerometers. CIRIA guide C764 Hidden Defects in Bridges – Guidance for Detection and Management lit the torch for the new SHM guide by recommending that inspectors and engineers regularly ask key questions of the assets in their care – “What can I see ?”, and “what can I not see ?” applying this both to the review of historic information and the inspection itself and its content. Invariably what we cannot see results in lack of thought over time, resulting in potential closure of the asset or worst still, failure and collapse.
Despite improvements in technology the frequency of unexpected events with severe consequences has not reduced. The Ponte Morandi (Genoa) bridge crash, Whaley Bridge (UK) dam partial collapse, and the Mirepoix-sur-Tarn (France) bridge collapse are all examples of events occurring during the writing of the report. In each case, warnings could have been provided of and failure prevented if more knowledge, the right knowledge, had been gathered and passed to both owner and user, prior to the event.
Covid-19 has highlighted the importance of communication of the condition and vulnerability of our human health, and of the presence of what can attack that condition. The need for communication with the health of what we own in society is little different. We are responsible for what we own and put out for use. This applies to waste, to everything we create, and to everything we inherit. Everything has value, but it has little value if we look after it poorly and know too little about it. Passing on responsibility to someone else is not an option. We are responsible for our society and what it contains. Knowledge and monitoring place an essential part in ensuring that we act responsibly.