To deliver on this project, SGP chose international engineering and consulting group SYSTRA, headquartered in Paris, as one of their major partners on this ambitious project. With experience in delivering major rail engineering projects, SYSTRA was chosen to design the linear infrastructures, tunnels and elevated superstructures and coordinate with other partners.
The Grand Paris Express will add an extra 200 km of tunnels and tracks, 68 new underground and overground stations and five infrastructure maintenance sites, involving more than 120 people on the project team alone. Because of an overcrowded urban environment, the construction will also involve vertical develop¬ments on top of the stations and maintenance sites, such as offices and multiple real estate projects. In addition, the stations will also act as focal points for urban development, with the aim of kick starting other developments in the local area.
Sylvie Cassan, Head of BIM development and deployment in France, SYSTRA, says “This is a massive project for the Paris metro, and one of the biggest infrastructure projects seen in France for a number of years. Given the advances in BIM and related technologies, we realised this project was a fantastic opportunity to take advantage of new tools to deliver innovation and savings. Within two years we are doubling the size of a network that has taken 100 years to reach its current size.”
Saint-Maur Créteil Station, courtesy of SYSTRA and Agence Nicolas Michelin et Associés.
“Autodesk Customer Success Services helped us to build a strong standard foundation based on their wider industry experience. We’re integrating our unique know-how and robust processes, that we’ve developed over years as an innovation leader in railway infrastructures, into our very own BIM Standards. These standards are going be a competitive advantage for SYSTRA during the
The GPE is the first ever deployment of BIM (Building Information Modelling) on a large infrastructure metro project in France. All members of the consortium led by SYSTRA, including engineers, integrated architectural agencies and an independent architectural partner proactively chose to use BIM, even though there was no French national BIM mandate in place.
Several stations in the GPE are underground, and as a result are highly technical structures, subject to severe structural constraints. These stations range from 14 to 36 meters underground, with as much as 75 per cent of their structure below the surface. The structural constraints of underground construction, including vital structural support, had to be adapted to ensure the stations are user friendly and safe. Adding to this was the need to take into consideration the superstructures to be built on top of some of these stations.
BIM has been used on this project to facilitate data exchange, especially between civil design with AutoCAD Civil3D and architectural design using Autodesk Revit, as well as to improve 3D coordination and designs. Thanks to this project, SYSTRA extended its BIM usage from Revit and Navisworks to include Civil3D for rail infrastructure design. BIM was successfully used for track alignment, utilities, hydraulic system, overhead powerlines and telecom while interfacing with architecture, structure and MEP services.
Sylvie Cassan, Head of BIM development and deployment in France, SYSTRA, comments “Unique to this project is how a big team of various architects and engineers from different sectors and specialities worked together. Many of those involved in the project were not used to this way of working in a BIM based collaborative environment on infrastructure projects. As a result, even before the project started there was an extra level of unplanned complexity. BIM was a massive help for allowing us to overcome this challenge and concentrate on delivering the project.”
Saint-Maur Créteil Station, courtesy of SYSTRA.
Getting on board with Autodesk Customer Success Services
As part of this project, SYSTRA contracted Autodesk Customer Success Services to take advantage of its expertise on various elements of the project. Autodesk’s involvement commenced with implementing BIM for the line 15 station design which allowed SYSTRA and Autodesk to define the governance, processes and technology to be used for the most critical element of the BIM model, including model authoring, drawing production, 3D coordination and design review. The Autodesk Customer Success Services team also helped SYSTRA to build a strong technological foundation for the infrastructure design element of the project.
“Railway engineering design requires managing complex systems embracing multiple disciplines such as civil, stations, MEP, signalling, track design. It was of the utmost importance for us to approach the interaction of these different domains in our BIM processes with a global asset management vision. Autodesk customer success services helped us to build a strong standard foundation based on their wider industry experience. We’re integrating our unique know-how and robust processes, that we’ve developed over years as an innovation leader in railway infrastructures, into our very own BIM Standards. These standards are going be a competitive advantage for SYSTRA during the age of digital railways industry.” Eric Pruvost, corporate BIM director, SYSTRA.
At the same time, Autodesk assisted with three additional key initiatives to facilitate the deployment of BIM at a corporate level within SYSTRA. The first element of this was to help reach an agreement regarding the goals and roadmap for SYSTRA’s overall BIM transformation. Following this, Autodesk then helped create a framework for SYSTRA’s Corporate BIM standards. The final part of this work was to deliver a series of tools to facilitate the organisational change management needed to make the most of BIM, including educational webcasts, an IT infrastructure assessment and a BIM maturity assessment.
“Autodesk is pleased to collaborate with SYSTRA, a leader in the rail engineering industry, and share BIM implementation expertise from its Customer Success Services teams. Through their digital transformation journey, not only is SYSTRA establishing their competitive advantage but enabling a better collaboration process across the value chain of Railway Engineering, Construction and Operation.” Frabrice Dreneau, director Customer Success Services, Autodesk.
Infrastructure maintenance site at Vitry, courtesy of SYSTRA.
Keeping the Project on Track
BIM-based collaboration has been critical for accelerating the delivery, increasing the quality and reducing the overruns between stakeholders for the GPR project. During the advanced preliminary design phase, the work-in-progress model was shared weekly, ensuring each stakeholder was using the latest version. This approach also meant that during the detailed design phase, the models from different disciplines could be synchronised in real time. Although this new BIM based methodology required additional time for the teams to become familiar with the solution, the final result was a robust design and much better collaboration.
In addition to this, BIM allowed SYSTRA to simplify the transition from the preliminary stages of the project to the detailed design phase. This has been achieved by using BIM to create dependable production delivery workflows, enabling the engineers to make changes to the same model, improving version control and reducing the number of errors getting past the planning stage. This simplification has been supported with features of the BIM solution, such as templates and a master object catalogue allowing remodelling and a coherent replacement of modelled objects in multiple sub-projects. An example of this was the MEP team creating a specific model of stations containing proposed structural voids and recesses which the civil engineers needed to review. This collaborative model could be updated in real-time, using new metadata (such as material properties or fire-resistance ratings) and enriched geometry.
Saint-Maur Créteil Station, courtesy of SYSTRA.
The use of BIM to collaboratively design the maintenance site was an opportunity to measure the capacity of data-exchange tools and the interoperability between Revit and Civil 3D. It meant that this collaborative design was more robust and reliable, enabling the construction phase to stay on schedule. Data for communication can then be extracted directly from the digital model, helping ensure a direct representation of design data, leading to further time savings.
This benefit of improved collaboration due to BIM has also been realised between the architects and engineers. Civil engineering costs for the underground stations on average represent between 70-80 per cent the total structure costs. Using a 3D model, it was possible to optimise the design and this led to optimisation through the reduction of the total volume of the stations and the cost of the moulded retaining walls. This also means that a more efficient use of underground space has reduced the amount of excavation and resulting spoil, further generating financial savings as well as limiting the impact on the environment from spoil transportation.
“Using digital models allowed us to be much more efficient with every phase of the project. Reducing the volume of the stations is a key example of this, as it not only reduces excavation time, but limits waste and allows for a more efficient use of the limited underground space we have,” explains Sylvie Cassan, Head of BIM development and deployment in France, SYSTRA
Another challenge unique to the GPE project was the requests from the client for rolling-wave modifications to the planned work, based on new passenger flow estimates, and required frequent changes to the size and location of elevators and escalators. Thanks to the BIM model, the impact of this on the overall designs could be quickly measured, leading to significant time savings. In addition, the quantity surveyor could work directly with the BIM model to estimate quantities, helping simplify rolling-wave planning and producing quicker and more reliable estimates of structure costs.
The adoption of BIM has accelerated the deployment of collaborative GIS models (incorporating data such as building surveys or geotechnical metadata), which has helped the overall 3D visualisation. It means that models and analytical studies based on geo-referenced data are coordinated and coherent. In the future, the BIM and GIS models will be able to talk to each other, and this data could then be used to analyse the risk of subsidence in buildings around the stations.
In addition, the digital BIM models can generate 2D and 3D views to allow SYSTRA to inform and consult residents and institutional partners that will be affected by the future stations. SGP has also integrated the BIM model in its own town-and-country planning models which give a 360° view of the station in its urban context. These contextual models can be used to demonstrate to residents what the station will look like in a real-world context, helping to build understanding and support with those affected. This is especially important for SYSTRA to demonstrate the resulting benefits following sometimes lengthy construction work.