The ground improvement solution
The solution involves the construction of 6,448 stone columns flexible inclusions between 6 and 9 metres deep over an area of 22,500 m². The columns strengthen the compressible layers of anthropogenic fill and quaternary clayey silts and terminate in the compact tertiary sandy clay layer.
Our teams have to work around the significant constraints imposed by airport activity, which include maintaining air traffic during work on site, and scheduling operations over day shifts and night shifts.
Daytime working must comply strictly with the height limitations dictated by the takoff cone of individual aircraft types. Although the height limitation is suspended at night, working hours are reduced (the maximum period is from 11:30 pm to 05:30 am) and governed by the variability of air traffic schedules.
Two stone column machines are used for this major project to offer maximum flexibility in terms of soil conditions and on-site constraints. A compact short-mast (SPD) drilling rig delivers maximum production during the day, while a traditional Enteco E500 rig reaches greater depths at night.
The work begun by Menard in October 2019 were completed in Quarter 2 of 2020 ahead of the new section of runway being commissioned in 2021.