{"id":9453,"date":"2025-11-10T11:50:32","date_gmt":"2025-11-10T10:50:32","guid":{"rendered":"https:\/\/ingenius.ecoledesponts.fr\/?p=9453"},"modified":"2025-11-10T11:54:54","modified_gmt":"2025-11-10T10:54:54","slug":"assessing-the-environmental-performance-of-railway-projects","status":"publish","type":"post","link":"https:\/\/ingenius.ecoledesponts.fr\/en\/articles\/assessing-the-environmental-performance-of-railway-projects\/","title":{"rendered":"Assessing the environmental performance of railway projects"},"content":{"rendered":"\n\n\n
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Usine Saarstahl Rail \u00e0 Hayange – Rails de r\u00e9cup\u00e9ration destin\u00e9s \u00e0 \u00eatre refondus. Cr\u00e9dit : Arnaud Buissou \/ Terra<\/figcaption><\/figure>\n\n\n\n

We met with Asmaa Benzidane<\/strong>, a PhD student at the Navier Laboratory, who is working on a thesis as part of the national MINERVE<\/a> project, entitled Environmental Performance Analysis of Railway Projects: integrating BIM with Life Cycle Environmental Assessment.<\/em> Her work focuses primarily on railway infrastructure<\/strong>, Life Cycle Assessment (LCA), and the integration of environmental data into digital models (BIM), with the goal of assessing the environmental impacts of railway infrastructure.<\/p>\n\n\n\n

Why did you choose to work on the environmental assessment of railway infrastructure?<\/strong><\/p>\n\n\n\n

The railway sector presents a fascinating paradox as it is both a key pillar of the low-carbon transition and a sector with significant requirements in terms of materials and energy, especially during the construction phase, but also throughout its operation. This contrast raises a question that I aim to answer through my PhD project: How can we design, build, and maintain a railway line while reducing its environmental impact?<\/p>\n\n\n\n

My thesis is part of the national MINERVE project, which aims to provide industry stakeholders with robust and practical methods to better incorporate environmental considerations into their decision-making processes. It combines Life Cycle Assessment (LCA) with BIM digital modeling, to more accurately quantify the environmental impacts of the railway sector and make it easier to consider these impacts from the early stages of project development. The Navier Laboratory, where I conduct my research, offers an ideal environment for this work. I can draw on expertise in materials sciences, modeling, and data engineering to develop tools that are closely aligned with real-world conditions, and that will ultimately be used by professionals in the sector.<\/p>\n\n\n\n

How does the integration of BIM and Life Cycle Assessment (LCA) improve the environmental evaluation of railway projects?<\/strong><\/strong><\/p>\n\n\n\n

BIM (Building Information Modeling<\/em>) or collaborative digital modeling of a structure, makes it possible to describe in detail the objects that make up the structure, including their properties. By combining this method with LCA, we can quantify the environmental impacts of a construction project or object over its entire life cycle, from the design phase to deconstruction. This integration allows us to link both the quantities and the so-called \u2018living\u2019 parameters, i.e., data derived from the digital model that evolves in real time, to established impact models based on previous LCAs.<\/p>\n\n\n\n

To do this, I automatically extract the quantities of materials required (steel, concrete, ballast), that are used in the construction process, from the digital model. Then, in the testing phase, I also incorporated different variants, such as material thickness, low-carbon formulations within the model, and especially the construction phasing, which refers to the organization and scheduling of the various stages of the project. Finally, I carried out a comprehensive evaluation of environmental indicators that exceed carbon impact thresholds and included indicators related to biodiversity, such as land use and transformation, resource consumption (water, energy, etc.), and even human health. This makes it possible to identify thresholds that should not be exceeded during the design phase.<\/p>\n\n\n\n

What main technical or methodological challenges did you encounter?<\/strong><\/strong><\/p>\n\n\n\n

My first challenge was ensuring seamless data interaction. BIM objects are not always defined in the same way, depending on the databases or software used. This meant I had to harmonize them first, to be able to then make proper use of them. Next, I had to choose the right level of detail in my models. Too much precision makes the system too complicated to manage. On the other hand, data that is overly aggregated can lead to a loss of relevance. To solve this issue, I worked with so-called parametric assemblies, i.e., rather than modeling each component of an object separately, multiple elements are grouped together. This approach simplifies data management while maintaining precision.<\/p>\n\n\n\n

Another major challenge is uncertainty. Certain parameters, such as traffic, the lifespan of installations, maintenance plans, or even the end-of-life of materials, have a significant impact on the results. To anticipate this, I came up with various plausible scenarios, introducing variations in maintenance, replacement, or reuse of materials, in order to better assess and compare potential long-term impacts and identify the most suitable configurations.<\/p>\n\n\n\n

Another difficulty I encountered was accounting for biodiversity impacts and land use. These aspects are often overlooked in standard assessments, but they are central to my research. To address this, I used the European Corine Land Cover inventory, which describes different land use types (forest, urban areas, grassland, etc.). To translate this data into measurable environmental impacts, I created a correspondence table, which I then integrated into my model. Finally, the greatest challenge is ensuring that industry professionals can make use of the tool. I am currently working on clear presentations of the results, as well as simple modeling guidelines that engineers could easily apply to their own projects.<\/p>\n\n\n\n

How does your work contribute to the objectives of the MINERVE project, particularly in terms of carbon neutrality and climate change adaptation?<\/strong><\/strong><\/p>\n\n\n\n

The BIM-LCA integration makes it possible to identify major impact areas, such as concrete, steel, earthworks, or even the amount of energy consumed on the construction site, while also measuring the actual effect of alternative solutions. For example, we can quantify the impact of using low-carbon concrete formulations, prefabricated materials, or the reuse and recycling of materials. This helps to promote these practices and gradually integrate them into future projects.<\/p>\n\n\n\n

As for climate change adaptation, I conducted numerous tests on different variants designed to be resilient to climate hazards such as urban heat islands, freeze-thaw cycles, and extreme weather events. These scenarios were compared to maintenance strategies specific to the railway system. Water and soil management is also integrated into the model, which further supports the consideration of climate-related issues. Finally, a key part of my contribution to the MINERVE project is helping to improve maturity on a national scale. Since our goal is to promote the widespread adoption of shared practices among public contracting authorities, my work will support the harmonization of methodologies and help accelerate large-scale integration of environmental concerns into railway projects.<\/p>\n\n\n\n

You’re currently working on a specific project, the future Bordeaux\u2013Toulouse high-speed rail line. How does this collaboration with SNCF help reduce the carbon footprint or environmental impact of this part of the network? And how can these results be scaled to other rail projects?<\/strong><\/strong><\/p>\n\n\n\n

This collaboration with SNCF is essential because it provides real data and constraints that are specific to the Bordeaux-Toulouse project, such as construction phasing, types of structures, and issues related to cost, scheduling, and buildability.<\/p>\n\n\n\n

This enables us to:<\/p>\n\n\n\n