Facing technical challenges of underground works at the world tunnel Congress

Tractebel French specialists and experts were present at the annular World Tunnel Congress, whose 2019 edition took place in Naples from May 6^th to May 8^th.

They had the opportunity to present their latest works and thus showed their active contribution to the technical improvement with the publication of 6 scientific publications.

Back on the presentations concerning the reliable prediction of the ground movements induced during the construction of tunnels and their impact on the existing constructions.

Since 2015, Tractebel in France is involved in the Grand Paris Express project as Design Engineer for the infrastructure of Line 16th and Line 15 East, as part of two Join-Ventures and for the Société-du-Grand-Paris.

To address the new engineering challenge of the Grand Paris Express project, our french team developed in 2016 their own internal tool dedicated to the prediction and mapping using GIS*, of ground settlement induced during underground works in densely urbanized areas, and that also allows performing sensitivity and vulnerability analysis of impacted existing buildings.

Moreover, in order to perform reliable prediction of these phenomena, filed data recorded between 2010 and 1011 during boring the tunnel of north extension of metro Line 12 were construed. Indeed, Line 16 and Line 15 East tunnels are planned to be bored in the same geological context and this makes Line 12th a valuable feedback case, on which to improve design choices and risk assessment for settlement analysis, and particularly empirical and numerical calculation parameters.

Between 2016 and 2018, Tractebel in France has carried out Engineering studies for the infrastructure of Metro Line 15th East. The reliable prediction of the settlement that are to be induced while boring the future 23 km long tunnel and their impact on surrounding buildings was a key issue for the optimization of the project, that was addressed optimally using this newly developed tool and this feedback.

Currently, Line 16 is under works and firsts TBM are planned to start at the end of 2019. Our skills and know-how acquired since 2015 will be used for the follow up of these works and our feedback will be again extended and renewed.

These engineering works have been presented  during the World Tunnel Congress 2019 by Samy Mahdi through two specific papers.

Click here to know more on our geo-engineering expertise.

*GIS : Geographic Information System