Our experts participated in the AFTES congress in Paris

The French Tunnel and Underground Space Association (AFTES) organised its congress from 6 to 8 September in Paris around the theme "The underground, a space for innovations." A look back at this event.

A topic in the news

Tractebel, with its expertise in underground structures, was present at this congress. First during the conferences and poster sessions, but also by welcoming participants at our booth over the three days!

The AFTES focused on the potential for underground spaces today, both in terms of urban planning and in the design and building of structures - particularly with the assistance of digital modelling - and in the progress made in materials (digging, construction, etc.).

Among the initial findings were the early stages of low-carbon design as a cross-cutting concern in the transport engineering industry. As the event was less international than in previous years due to the travel restrictions still present, the focus was more on local projects such as the Grand Paris Express or TELT.

Geotechnical, modelling: our experts meet the challenges

The conferences, organised around four major technical and scientific axes, have made it possible to focus on the role of underground space in the city of the future and to innovation in the construction of underground structures. It is on this last theme that our experts have been able to illustrate their expertise, notably thanks to our participation in the Grand Paris Express projects.

Our Director of the Geotechnical and Underground Works Department, Pascale Massaad, and Imre Miszlay, Senior Engineer and manager of the station, were co-authors of the article “How can underground structures adapt to the presence of gypsum? The case of Grand Paris Express L16.2 Sevran-Beaudottes station”. A second article was written within the research project carried out by INERIS and CEREMA in collaboration with the SGP and the MOE-Tractebel on the Sevran-Livry station of the L16 of the Grand Paris Express. Pascale Massaad and Imre Miszlay contributed to the article "Adaptation of the constructive rules of engineering structure of Grand Paris Express in the Gypsum dissolution area."

Then Reza Taherzadeh, Technical Director Infrastructure, participated in the writing of the article “Experimental Studies and Digital Simulations of Plastic Clays.” This work was carried out as part of the return of the experience of the construction site of the White House station of the Greater Paris project. It presents the results of experimental studies and numerical simulations on plastic clays, as well as preventive and corrective measures against this major geological risk.

And finally Christian Noubissi also presented this thesis work under the supervision of Reza Taherzadeh, in partnership with CentraleSupélec, in a poster session. Three objectives are to be pursued in this work: The first is the determination of the true soil parameters by a back-analysis approach that takes into account the scale effect. The second objective is to examine the influence of tunnelling parameters on soil response in order to determine the 2D pressure that would simplify 3D modelling. Finally, the development of a rapid approach to estimate the settlement field over the entire linear from the first settlement measurements was achieved. In this section, soil parameter calibration and artificial intelligence (AI) methods are combined to provide reliable results with considerable time savings.

AFTES participants