BIM and infrastructures: feedback on the implementation of BIM processes on the A63 motorway widening project
BIM processes are already well used in the construction industry, unlike linear infrastructures. The fundamental differences between these two fields mean that the concepts defined for one are not directly transposable to the other.
The issues and challenges of BIM differ between the players in large linear infrastructure projects. Indeed, while the technical and geometric aspects will focus the attention of project managers, it is rather the concepts of operation and maintenance of the infrastructure built that will be at the center of the concerns of the owner. This positioning is logical when we know that it is this phase of the infrastructure life cycle that represents the major part of its total cost.
Therefore, the real added value of the digital model will reside in its semantic component. The relevant choice and quality control of the attributes entered within the latter via new Workflow is a crucial point that will make this digital twin accessible and searchable by the motorway operator. Thanks to the efforts of infrastructure design software publishers and the development of the first IFC formats specific to this field, it is now possible to produce 3D models that go beyond simple communication objects.
It is certain that the client is the actor for whom BIM is the most profitable. Indeed, it represents for him a formidable opportunity to reinforce the control of his projects, at all phases and thus improving the overall quality of the design and the construction. One of the client's wishes is to promote concurrent engineering and co-construction. This results in the taking into account, from the project design phase, of the requests and comments of all the stakeholders in the operation.
To assess the extent of the benefits generated by the implementation of these new collaborative processes, ASF's construction department and the company Ecartip Groupe Fondasol jointly carried out a test over a four-kilometer portion of the A63, in study phase.
This experiment made it possible to achieve several objectives:
- The production of a digital model of the A63 motorway. The existing 2x2-lane situation and the 2x3-lane widening project were modeled over 4 km (27 km by the end of 2017), taking into account all the structures traditionally present on a motorway infrastructure (toll stations, overpasses, underpasses, hydraulic structures, networks, etc.).
- Drafting of a standard convention for linear BIM infrastructure projects. The latter respects the methodological guide for drafting a BIM convention published by Mediaconstruct, the association representing BuildingSMART in France.
- The development of Cartage, a multi-source data aggregation platform (GIS, digital models, CAD, DAO, PDF, etc.) which is based on a realistic 3D base resulting from a LiDAR survey carried out over the entire linear of the A63. This tool makes it possible to fill the void and ensure interoperability and exchanges between the world of GIS and that of BIM. Widely used in project reviews where it replaces paper plans, Cartage democratizes the use of digital models by all project stakeholders.