LINE 15: THE FINAL DIAPHRAGM WALL FOR CHAMPIGNY
Work began on the Champigny site - line 15’s first - back in March 2018, and it was the last to be finished. The final concreting of the North Red Box and the intermediate Box phase was completed on 17 March and is set to be followed by a one-month immobilisation phase. This offers us an opportunity to take a look back at this exceptional project.
It will feature a total of 775lm of 1,500mm diaphragm walls, more than 50,000m3 of concrete, nearly 4,000 tonnes of reinforcements, and the setup of 130m of 800mm temporary diaphragm walls equipped with glass-fibre reinforcements and is Grand Paris and Sefi-Intrafor’s highest-volume diaphragm wall project.
From a technical point of view, the team has been faced with major geotechnical issues in some strata, causing scheduling delays that had to be offset by changing drilling methods. It has turned out to be an outstanding success for the 30-person team led by the major projects manager, various works engineers, and a worksite supervisor. Congratulations to them all.
As the site shutdown caused by the COVID-19 lockdown resulted in scheduling issues, work on the site resumed on May 11 with the initially scheduled immobilisation phase, providing an opportunity to perform a range of much-needed maintenance work and repairs.
Finally, the project will end - from 11 June - with the A.G.E. (Avant Gare Est, i.e., east pre-station) diaphragm walls. This final phase will see the setup of more than 10 panels (width; 1.50m, depth: between 40 and 60m) over 5 weeks then the installation of 2 closing panels in August.
