A2-M2 Cobham, Junction 4 Widening

The A2/M2 contract was for upgrading and widening the existing carriageway between
Cobham and Junction 4. Carillion Piling undertook the work, that included the construction of 84 2400mm diameter soakaways to a value of £1.13m.

As part of the A2/M2 improvement project some large soakaways were installed adjacent to the M2 motorway. Working on or adjacent to the hard-shoulder. Carillion Piling drilled 2400mm diameter boreholes upto 35m deep to facilitate the installation of 2000mm diameter steel soakaway liners.

Each liner was assembled on site using corrugated steel sections. Some of the sections were perforated. Once lowered into the borehole, gravel was placed around the perforated section, a bentonite barrier was then placed and then concrete was used to fill the remaining annulus between the ground and the liner.

These soakaways were situated either side of the motorway for a distance of four miles

Client: CSM
Piling rig used: Casagrande C50
Contract value: £1.2m