Future-proofing our bridges in a changing climate podcast

Transcript

Future-proofing our bridges in a changing climate

Rebecca Torr (RT): Hi, I’m Rebecca Torr and welcome to the Emerald Podcast Series! In today's episode, we’re exploring the world of ageing infrastructure in cities, with a particular focus on bridge infrastructure. Our guest is Dr Stergios Mitoulis, Associate Professor and Head of Structures at the University of Birmingham, and Editor in Chief of the Journal of Bridge Engineering. We'll be discussing the sustainability and resilience of bridges, the role of smart city initiatives, advancements in sensor technology and AI, and much more. Join us as we explore the challenges and opportunities in maintaining and upgrading our vital bridge infrastructure.

Stergios Mitoulis (SM): Thank you very much, and thanks for the invitation. So yes, many bridges designed for cities and urban environments, they were actually built decades ago, and mainly the 60s and the 70s. And thus they're currently reaching or have surpassed their intended life spans, and that leads, obviously, to widespread aging issues. All sorts of problems are now accumulating. So there is key challenges, and that includes structural deterioration, corrosion, material fatigue, which threaten safety and require frequent inspections and repairs. It is not only the deterioration of the materials and the bridges and the impact of climate change on the infrastructure at the same time, bridges and also other infrastructure in our cities and urban environments, they are faced with increased loads and increased demands. For example, the lorries are becoming heavier, the traffic volumes become greater, and at the same time, climate exacerbates hazards such as floods and sea level rise. So all these deteriorated bridges, they also have to face extreme events, extreme threats and stressors, and hence we need to make sure that we proactively strengthen our bridges to avoid failures and destruction in our urban systems. 

RT: I think it's really interesting. And most of us, we go over bridges quite frequently. You know, they connect one piece of land to another, but you know, how important are bridges? And you know, how does that contribute to sustainability and the Sustainable Development Goals? I mean, I was just wondering sort of how they could be designed or upgraded to further support sustainable development.

SM: Yes, thank you for the question. This is a very interesting question, and that brings into my mind an advert of a construction company back in the day that was constructing a bridge along a major highway. There was a big sign at the entrance of the bridge saying, bridges connecting people. And I think that's what it is. Bridges are the structures that minimise the time of commute, help people to go to their jobs and their loved ones faster and safer, and help us cross rivers valleys and other natural obstacles that would be impossible to do otherwise. So yes, bridges are contributors to sustainability and looking at more tangible Sustainable Development Goal-based performance indicators, we know that bridges enable efficient transportation and connectivity. And you know if you have a bridge that is closed, that increases the travel time and the distances and the CO2 emissions that we meet with the environment, so bridges reduce CO2 overall. They are also designed as robust joints within our transportation networks, and hence they enhance climate resilience by making our cities and infrastructure more resilient and more robust against climate change. For example, imagine a network that has been disrupted because a bridge is closed, obviously the network will become less resilient. Whereas if you have more bridges in place, and hence more alternatives to go from A to B, then automatically your system becomes more resilient, and hence more sustainable. 

RT: I think that's really interesting. And when we talk about sustainability, we often talk about smart technologies, and obviously there's been loads and loads of changes recently in terms of, you know how smart technologies can help us build better and it's often connected like that, that something smarter is often better and more sustainable. And that, I mean, that might not be the case. Just because it's a new technology doesn't necessarily mean it's sustainable. But I just wondered, from your perspective, how you see sort of those, those initiatives, those sort of like, those new technologies, and how they intersect with bridge infrastructure and and what role really do smart bridges play in the overall vision of smarter urban environments. Are smarter bridges better? 

SM: That's a very interesting question actually. I'm a fan of technology. I love technology. I love data. I love the new era of artificial intelligence and monitoring and use of satellite imagery for managing and operating infrastructure. So I think in the concept of a smart city, and the initiatives around smart cities, we do need to prioritise data driven infrastructure, and that includes bridges, smart bridges, where sensors are installed and the sensors are part of an Internet of Things, technology to provide, for example, real time monitoring, real time data and information to the end users, to the to the drivers, and also predictive maintenance inside. So it's not only about the end users, but it's also about how managers operate, how managers make decisions for strengthening and adapting bridges to climate change. So the way I imagine it and the way it's happening now, actually, but it's at the very early stages of R and D that smart bridges, they can enhance urban resilience by enabling, for example, just going to give a couple of examples, automated response to natural climatic and human use threats and stressors. Imagine you have a bridge that has a heavy traffic or, you know, an earthquake that strikes a bridge or or extreme temperatures. This is the kind of threats that inflict changes to our infrastructure and to our bridges and these systems, this sensor sensing technologies, they can give us this information so that we can make decisions very quickly as to whether the bridge is safe. And there is also a great area there and a great opportunity to strengthen a more sustainable future, to support a more sustainable future by optimising, for example, traffic flows and reducing congestion and emissions. So yes, we live, we live in in times where infrastructure is strongly interconnected, and, you know, there is strong interdependencies between our infrastructure, our hard infrastructure, and our soft infrastructure. Imagine the data in the ICT systems. And so we need to look into our systems from a cyber physical point of view, which means that cyber systems and physical systems, they all shape that the world as we know it, the cities that we know them these days, these systems are said to be more complex, but at the same time, potentially more resilient, because they give us more opportunity to react and make decisions quickly. So when you have, for example, an alert, some sensors, you can very quickly give an early warning to people so that they don't use the bridge, and hence reduce the risk of accidents, so they reduce the risk of fatalities. But at the same time, technology also comes with some, you know, some challenges, and the challenges are okay, how do we operate our bridges? By using these huge volumes of data, of, you know, multiple sensors. How do we integrate data from different sources, from cameras, from, you know, thermometers, from from devices that measure displacements and traffic. So there's also always a challenge there, and and, of course, a great area for research. 

RT: I think it's a really exciting time, isn't it, to be in this area of research and to see how those smart initiatives and those smart technologies can really make a difference. And as we all know, we've for the last few years, we've all been very much talking about artificial intelligence and and sort of the role that AI can play in, whether it's, you know, in our everyday lives, or it's, you know, we look at construction and infrastructure, sort of the role it can play there. And you know, obviously, you know, you were talking there about sort of understanding what's going on in real time. And I just wondered what AI and sensor technologies can do to help us monitor the health of aging bridges? And are they effective? I mean, perhaps it's early days yet, but do you think they will help us extend the life of bridges? Is that something that's possible?

SM: Yes, I certainly believe so. Not only there is, there is a lot of opportunity out there with the use of AI, data technology, data mining and so forth. So I'm just going to give some examples, because AI and and, you know, bridge management, or infrastructure management, if you like, have already, have only met very recently in the domain of infrastructure management. So imagine you have sensors that can detect stresses, vibrations, temperature, traffic, corrosion, almost in real time, and that would allow you to continuously monitor the health of your bridge. Now, an AI algorithm or a machine learning algorithm or a deep learning algorithm, all being under the same umbrella of artificial intelligence is that it can very quickly, rapidly, almost real time, process data, and that means that you can now bypass the, let's say, analysis stage, where you need to analyse the entire bridge, you know, from A to Z to find out what might be, what might be, you know, a plausible scenario, or a potential outcome from that. So in simple words, even though AI is, you know, we consider it as a black box these days, and we try to make sure that we make it explainable at the same time, it accelerates the decision making and the outputs in our bridges, meaning that we can make decisions very quickly, very efficiently, with very high accuracy. And AI can also help us build meta models and bypass the need to analyse. For example, use finite element software to organise bridges, most of the bridge engineers, you know, traditional bridge engineering has been using finite element modeling. Now they we know that to some extent, this can be bypassed. So these technologies have been proven to be very effective in extending this lifespan, making decisions and enabling timely interventions. And it is really a fascinating area around these technologies. However, we always need to be cautious and we always have to have the engineering angle to our problems. Okay? So whenever we get results from AI or, you know, we get a warning or or a decision based entirely on AI analysis, I would suggest, you know, use your engineering feeling. Use your engineering sense, your feel for the structure, and make sure that the results are interpretable, explainable, and you can actually justify where these results are coming from. 

RT: I think that's excellent advice, because, I mean, all of us have probably experienced, if you've ever used, you know, some of these, you know, like ChatGPT, some of the results that come back, you know, can be fabricated or, you know, I know there's a lot better technologies out there and, you know, but that's just on an everyday level of experience that, you know, it's not necessarily completely accurate. So, you know, it's interesting to hear you explain that. You know, this is not the answer. We need our expertise. We need the people that you know understand how bridges work, you know, from a structural point of view, you know, physically, not just the the intelligence, but yeah, I mean, I guess you know, that sort of brings me on to some of the other challenges around smart technologies for bridges. You know, smart technologies are very costly, and we do have the capability with these new technologies to do great things and but, you know, barriers are what prevents us from sort of just skipping ahead and making everything smart. And perhaps there are barriers related to costs and training and even public perception. You know, perhaps you know what I've just described about, is it, you know, safe, or is it accurate? Are we going in the right direction? So yeah, maybe you can just sort of talk us through the challenges around implementing smart technologies.

SM: Yes. Thank you for the question. This is actually a question that I've been asking myself, and you know, all the researchers in my research group around the cost of these technologies. Is it feasible? Is it justifiable to use this technology? So yes, on the one hand, there is high initial cost for installing sensors and developing data management systems that can limit you know, this can limit the adoption of these systems, especially in cities with budget constraints, managers always deal with budget constraints, so we always need to bear that in mind. So implementing and maintaining these technologies requires at the same time, not only investment financial development, but also specialised knowledge and training. So you need the people the right people in place to, you know, process these data and make decisions based on data. So at the same time, there is public perception with issues that may arise around privacy. And some communities are also, you know, worry about potential disruptions. They, you know, concerns about, as I said, around privacy with smart infrastructure. But at the same time, I have to remind, you know, all those people who challenge digital technologies, the fact that digital technologies could have given us warning in many occasions and avoid, you know, disruptive events such as, for example, the failure of the of the Polcevera, or also known as the Morandi bridge in part of Italy that took the lives of 43 people, or the failure of the Carola bridge, very recently, in Dresden, Germany, and the collapse of another example, the Francis Scott Key Bridge in Baltimore that costs billions and billions of dollars. So I believe using and leveraging data and use it for the right purpose, that you can actually save lives. One of my concerns when I'm using data and these are technologies, is how do I store, how do I federate this data? And as I mentioned before, how do I interpret this data, all these results that we get from AI in in, you know, milliseconds of time, how do we trust this result? And I think the answer here is to, you know, train, a good bridge engineer. Train, you know, good engineers, so that they they have an understanding of that, and they know what to expect from their structure, so that they don't, you know, fully rely on AI results, but rather, you know, also rely on their engineering instinct.  

RT: I think that's really excellent advice. And, yeah, I mean, I think we're still quite early days, aren't we, in what we can achieve, you know, just by relying on AI and other technologies purely on their own, I hopefully it will always be a human interaction with them. And I guess, you know, we sort of looked at, we've looked at smart technologies now. I guess the other key thing is, is policy, it could be in relation to, you know, should there be policy related to sort of data, you know, smart technologies and data, you know, and security and things like that. But yeah, I just, I just wonder, from your point of view, if there were any particular policies that should be implemented to enhance infrastructure resilience, you know, especially relation to ageing bridges. And I don't know if you've seen any gaps, because you've mentioned a few cases there where probably those bridges should have been maintained, or, you know, something should have happened. Perhaps you've you've seen it in your your research and witness where, you know, policy could have made a difference. And what can we do now? We can't help what's happened now, but what can we do looking forward? You know, what policy, what can policy makers do? What should they be paying attention to?

SM: Yes, thank you for the question. That's, that's an interesting one, because that that goes well beyond my, you know, engineering expertise. That's, about policy. However, engineers are also responsible for for policy making and standardisation, which means that we, you know, we develop the next generation of design guidelines for designing bridges, for example. So, yes, one thing that comes to my mind is that there is no good structure without good policy in place and and that applies to any kind of infrastructure assets, any critical infrastructure, any urban environment, any build ecosystem. So cities should adopt policies that mandate regular, for example, bridge inspections and prioritise preventive maintenance and allocate dedicated funding for infrastructure resilience. Now the question here is, how quickly we can, you know, put legislation in place and put policy in place to actually require that from the engineers and from the governments. How quickly can we make decisions to convince governments to allocate more funding for preventing? You know, preventive or proactive, if you like, adaptation measures for bridges that can help us design rational interventions and [protect] bridges against emerging threats in of climate change, for example, because we know that being reactive in case of hazards, for example, strengthening bridges after a flood happens, after a fire happens, is not as efficient as being proactive and at the same time doing things in a proactive way will also save a lot of CO2 emissions, and we will do things, you know, by taking our time and designing appropriately structures and so on and so forth. So the question here is, how much policy we need? How quickly we need this policy? In my opinion, we need this policy as soon as possible. And last but not least, how much funding can we allocate in the near future to bolster, to strengthen our bridges proactively.

RT: Thank you very much. The hot topics around sort of climate change and and how extreme weather is affecting you know, our lives and our cities and our infrastructure. And I think, you know, it makes sense that right now is the time to pay attention to the funding and the policies that will address these issues, because they're not going to stop. They're not, you know, climate change is happening, and it's happening at pace, and it is impacting the way we live. It's impacting our infrastructure and, and it makes sense that now is the time, if we've never done it before, as much as we we should have we should do it now and, and I guess you know, it will be quite interesting from your perspective, how you see climate change impacting our cities, our urban environment. I mean, what do you think are in the near to long term consequences of climate change? What do we need to be doing to to address this? Because obviously, bridges are being affected quite dramatically, as you've described.

SM: Yes, that's correct. So bridges are affected by climate change in a very dramatic way, and we have seen that over the years, with bridges failing more and more frequently over the last, I would say, five to 10 years. And that is not only the accumulation of deterioration of the materials. It's also climate change, obviously. So climate change, at least from the side, of bridges has increased dramatically the frequency of extreme weather events such as flooding, for example, and hurricanes and heatwaves we have seen extreme temperatures a couple of years ago in the UK. And these accelerate, obviously, the you know, the deterioration of the materials, the materials lose their strength gradually. At the same time, we also have seen a shift in the way bridges respond to certain hazards, and that's because, for example, you know, foundations are scoured. Scour is a is an effect of flooding. So the soil is removed around the foundations, the piers are becoming more flexible, and hence more vulnerable to floods. So yes, flooding and erosion as a result of climate change, especially in coastal and river in areas compromise bridge foundations and they pose, you know, high risk to both the stability and the safety of the bridges. So these are some examples of bridge deterioration. Of course, you know, we also know that extreme precipitation and more frequent precipitation leads to faster, you know, corrosion of the reinforcements. The reinforcements is pre stressing, still inside the concrete of bridges becomes rusty very quickly. And this is alarming, obviously, and especially for bridges, because bridges are delicate structures. We don't have them in our minds as being delicate structures, but they're much more vulnerable and much more fragile than common buildings, and that's because they have great lengths. They have less support, you know, less columns than the than the building, which means that small changes in their structural system can lead to collapses. And in fact, the very recent failures have actually proven that point, that bridges are very valuable, very fragile to climate change.

RT: Yeah, it's so interesting, isn't it? And you mentioned, you know, sort of in the last five to 10 years, we're seeing the impacts specifically, you know, intensifying because of climate change. And, you know, more and more bridge failures. And I mean, this isn't going away. So are there any specific technologies you know that we can take advantage of or new materials that really are going to help us to adapt our existing structures to future climate change challenges? Is there something that we can do to fast-track that? I'm guessing it's going to be quite expensive?

SM: Yeah, interesting point that they're not that expensive. I mean, yes, they might be slightly more expensive than the traditional concrete and still, but it's not, it's it's not out of proportion in terms of costs. So yes, there's been, there's been a lot of R and D, research and development around new materials. With high strength concrete, high stress, high strength steel and fiber reinforced polymers, you know, corrosion resistant steel and and all sorts of materials that we use for strengthening our bridges. This is, I would say, the very much like acid specific, traditional methods for strengthening our structures. And these are, these are not very different from the ones that we're using for buildings. For example, maybe the scale slightly different. But overall, I would say these traditional methods could be applied for buildings, could be applied for any kind of infrastructure asset, but for bridges, there is also advanced protective measures for for, you know, for combating climate stressors. So, for example, specialised coating and waterproofing techniques to help protect against corrosion and damage from flooding and salt water. There is also, if we look at, you know, larger scale infrastructure measures, we're looking at cities that implement climate adaptive design, such as elevated structures and resilient foundations to mitigate risks from, you know, extreme weather events. So there is technology in place, with a lot of focus on materials and traditional techniques, but there is also emerging technologies, emerging materials and emerging ideas, if you like. There is a lot of space here for innovation. And if someone looks in, you know, at the international literature, they will be able to support some very, very new research and R and D around, you know, flood resistance and flood strengthening of bridges. However, we do need to remember that it's again, it's more efficient and more cost effective in most of the cases to take some measures and adapt our bridges proactively. So before something happens, we know today that climate changes, if we don't do something today, and you know, a flood happens, or extreme temperature impacts our bridges, we will have to pay much more to strengthen our bridges, and we will do that in, you know, a in, not in the best way, if you like, which means that we will spend more money, more effort, and we will, we will develop something, we will design and construct, something that will be less sustainable than any proactive measure.

RT: So the time to act is now, basically, and I just wonder if I could shift gears slightly, because now that we have you here, and you are the Editor in Chief of the Journal of Bridge Engineering, I wondered, because, obviously, you were immersed in in this area, specifically about bridges. What sort of emerging topics or trends are you starting to see come through? Are you excited about researchers exploring? And I was also wondering about, you know, there's always sort of like a connection now, to sort of the impact of anything, you know, to do with infrastructure, you know, sort of the social implications. And I just wondered you might want to touch on, you know, have you seen much research in the area of, sort of fostering social and environmental resilience, potentially, and then, I guess, you know, how does the journal, support and shape the future of bridge engineering also through its publications.

SM: Yes, it's an exciting era, right? So we're going through the times where resilience and sustainability are in the epi-center of infrastructure assessments and design, as well as digitalisation, the way we use data and advanced technology. So yes, when I assumed my role as Editor in chief of the Journal of Bridge Engineering this year, my first editorial was titled ‘Bridge engineering, what next?’ And and I believe this describe, in my opinion, the future of bridge engineering from the lenses of not only, you know, the traditional consultant bridge engineer, but also much more, from a multi disciplinary angle, where bridges underpin the new philosophies of resilience and sustainability of structures and urban environments, and they also leverage digital technologies such as Internet of Things and digital twins for more efficient designs, operation and maintenance and the way they're, you know, this is a way to integrate them into our complex urban systems. So emerging topics around bridges, these are, you know, areas where we marry bridge engineering with emerging topics around satellite imagery, UAV enabled digital twins, digitalisation and also focus on methods for fostering new and existing bridges to climate emergency, and natural and human induced threats. So apart from the deployment of technologies, which is the, I would say, the technological bridge engineering side of things, we also have bridges that serve humanity, where bridges are the epicenter of you know, human engineering, and they serve as enablers of equality and diversity and help ending poverty. So I do believe that bridges are, you know, in the epicenter of critical infrastructure, of the of the critical infrastructure ecosystems, both in urban environments and outside cities. And I believe the Journal of Bridge Engineering is doing a fantastic work at the moment in attracting cutting-edge research around these topics and fostering cross-disciplinary collaboration, helping shaping, you know, we're shaping the the future of bridge engineering. At the same time, we're very proud that we also attract high quality papers from practitioners and designers and, you know, bridge engineers and consultants. So we are right in the epicentre of you know, traditional slash, I would say future bridge engineering from that point of view. And we would really like to see bridges transforming our urban environments and critical infrastructure.

RT: Oh, it's fascinating. And it's really exciting time to be an editor in this area and to see and to encourage research in these different fields. And I think inevitably, you know more I know from from an Emerald perspective. You know, we want to link our all our research to Sustainable Development Goals, and so seeing more research come through, and seeing how it impacts sustainability, and I mean, the, you know, the issues around resilience, I think you know for us, it's definitely something we support, and we're excited to see that, and you know and promote and encourage research around those areas. What would be your ideal scenario for bridge infrastructure in the next 20 to 30 years? What's your dream scenario? How would it look for you? And what really can we do in terms of balancing the current challenges of this with our structures that we've got while building new, resilient ones, you know, because inevitably we will, as a globe, be building because our populations are expanding. So you know, what does the future have in store? 

SM: So, yeah, that's an interesting question, isn't it, and thinking about all the challenges of of our world and urbanisation. Think about climate change, and what is the role of bridges in that, in all that, and how, how bridges will leverage solutions and will help humanity to grow. So for me, the ideal scenario for bridges would be to, you know, see bridges designed and maintained, having always in mind the resilience of our cities and our critical infrastructure, the sustainability of of our cities, of our urban environments, but also, you know, the sustainability of our communities, so building bridges to enhance the climate resilience of our communities to help us grow, and also bridges that will help us reduce inequalities, and also bridges that that embrace smart technology and integrate data, AI and digital twins, you know, being at the epicenter of future research. I think balancing upgrades of bridges with new construction is also an area that I would like to see a lot in the future. And I'm sure there's going to be a lot of research, R and D and construction in the near future. And of course, you know the way we prioritise reconstruction, or prioritise, you know, adaptation of our bridges, you know, try to select, try to choose the most vulnerable structures, the most vulnerable bridges in our complex building ecosystems, is also very, very important. So not only thinking about bridges from bottom up, you know perspective, where you know, you select the materials, you select the design, and you just, you know, design the bridges based on current design guidelines, but rather understanding and conceiving bridge designs using, you know, a top down approach, where bridge plays a very vital, a very key role into our communities, into our cities. I think that will be, that will be the basis of our design in the future. So I would say, you know, a systems perspective for designing our bridges. We also need to remember that bridges are connecting people, okay, so they also underpin our economies, our communities, and are part of part of our heritage and culture, and hence we have a duty to preserve our bridges and make them stronger, but also accessible to all.

RT: Thank you for joining us on this episode of the Emerald Podcast Series. We hope you found our discussion on ageing infrastructure and bridge resilience insightful and thought-provoking. A big thank you to Dr Stergios Mitoulis for sharing his expertise and knowledge with us. You can find more information and a transcript of the episode, on our website. A final thanks goes to Podcast Producer Daniel Ridge, and the studio This is Distorted. This is Rebecca Torr, signing off. See you next time.