Within the European economic system, or more precisely, within a space where goods and people move more freely, at an ever-increasing rate and, by all effects, road and rail infrastructure represent the skeleton of the Union and all of the individual countries that belong to it. Subsequently, it is clear that an efficient and well-maintained infrastructure system has a substantial impact on the economy, helping to increase the mobility of both goods and people. Furthermore, a rational infrastructural system favours a reduction in the environmental impact of transportation, which also renders it more sustainable.
In Italy, like most European countries, many of the constructions for the road and railway networks were built in the Sixties and Seventies of the last century, and many are now obsolete or are almost fifty years old.
This means that we not only need to update the existing infrastructure, but we also need to apply a different logic to planning, maintenance and management that views the system as a whole, not just as an individual system in itself. It needs to take into account the possibilities opened up by the new technologies, most importantly, digitalisation and the management capabilities of enormous quantities of data. Furthermore, it is important to remember that, more often than not, excess is not economically sustainable. This gives rise to the need to carry out a careful analysis of the project’s impact on an economic, local and global scale.
A snapshot that emphasises not only the importance of the various technical and scientific aspects but also and, above all, the centrality of a multi-disciplinary approach that can tackle this theme, while taking all of its parts into consideration. With this in mind, the Politecnico di Milano has set up a work group that brings together researchers and professors from different departments, from civil engineering and mechanics, to electronics, mathematics and management. The adopted approach is collaborative and interdisciplinary in nature, which are fundamental factors for supporting infrastructure managers in the definition of guidelines for the structural monitoring and integration of maintenance and diagnostic systems.
In this sense, an emblematic project is the collaboration agreement between Politecnico di Milano and Lombardy Region for the development of an expert support system for the decision-making process, planning, inspection and maintenance activities. An initiative devised to ensure adequate safety levels, while at the same time allowing for an efficient allocation of resources, based on the combined analysis of the system’s risks and impact.
The analysis systems have been defined on the basis of currently available documentation which, when integrated with verified traffic flow data, have allowed for the classification of the works into different typological clusters. The information was then inserted into a classic risk matrix, hence defining a logical assignment of the available resources. The level of priority of each work is then established according to the risk matrix, which is established through a two-tier evaluation process that combines the technical priorities – vulnerability and risks – and the functional priorities associated with the road network in question.
This approach is quite significant at this moment in time because, thanks to the measures introduced by the National Recovery and Resilience Plan, the relaunch of the infrastructure system will provide a vast amount of resources for the modernisation and introduction of new technologies.
More specifically, when establishing the level of priority of a given intervention within the system, there is a clear need for standardised databases, and their subsequent integration, which not only increases the level of knowledge on the infrastructure and the works of art, but also allows for more accurate planning for using the enormous amount of resources available. It is from this perspective that the Politecnico is collaborating with the Italian Ministry of Infrastructure and Sustainable Mobility (MIMS) to analyse the possibility of the integration of the monitoring and diagnostic systems into the maintenance plan framework for road network constructions
If we then move on to consider the purely technological aspects, it is important to underline how the reduced cost of the measuring instruments of these huge amounts of data, make structural monitoring (static and dynamic) a concrete and realistic verification system that allows for the real-time monitoring of the structural behaviour of the infrastructure, not only in terms of the works of art already installed but also in terms of new construction works.
Nevertheless, until this is possible, the measuring systems need to be planned and created with very clear and specific objectives in mind. In fact, there are various approaches for analysing data and evaluating structural behaviour. The two principal methods of analysis are divided into ‘model-based’ and ‘machine learning’. The former is based on the numerical modelling of the structure, while the second is founded on the pure analysis of the data. In particular, when applying the first approach, it is important to interact with a digital twin of the construction, which allows for the continuous calibration and updating of the model’s parameters.
The use of model-based methods is certainly extremely interesting for new works of art that have been designed using the BIM (Building Information Modelling) finite element models approach, or rather all of the elements that allow us to create a digital twin before the structures are built. Whereas the use of an artificial intelligence or machine learning system is preferable in the case of building works that present a wide range of complexities – another reason why it is often very difficult and consequently expensive to define a numerical model that can leave room for ample margins of uncertainty.
The same applies to structural monitoring techniques, where the definition of standards is of the utmost importance, not only for establishing a detailed definition of the most reliable and convenient form of the data transmission architecture, but also for verifying and proving the proposed system’s ability to detect and signal the onset and evolution of any eventual structural degradation.
Furthermore, the data analysis and acquisition capabilities of the structural data must be integrated with the informations gathered by the traffic management systems and self-driving and connected vehicles. A practical example of this is the possibility of knowing the weight of the load that travels across the infrastructural system, by tracking the vehicles using weighing systems installed at strategic points within the network. Knowing the overall load is fundamental when using digital twins because it allows us to identify the structural solution that can better withstand the incoming force.
Last but not least, one of the crucial activities of the polytechnic is highlighting the need for innovation in the educational offering and training of human capital. The Master’s Degree course in Mobility Engineering, together with numerous interdisciplinary courses represents a cornerstone for the training of technical figures who can capably plan and manage innovative systems.
Increasingly smarter cities, new types of vehicle, highly complex national and international transport links, safety and environmental impact, are just some of the critical issues that mobility experts will be called to solve in the futures. A sector that not only requires engineering and technical skills but also management skills and vision. These are the real priorities for companies and institutions that operate in this sector.
Hence, the university’s role is to act as an ‘adhesive’: on one side, by providing training and research, while on the other offering a strategic vision that is not only timely but can also fully embrace the prospects of systems. Infrastructure is the backbone of a country and if we want a modern and advanced Italy; if we are to be at the heart of this dynamic economic growth, we will need to be connected with the rest of Europe. But just like any advanced system, the realisation of this vision will largely depend on our ability to invest in innovation, education and research.
* Marco Belloli, Professor, Department of Mechanics, Politecnico di Milano is co-author of this article