MACCAFERRI HAS supplied 5,500m 3of gabions to retain chalk cuttings excavated during the construction of a Roadchef motorway services area on the M3 at Winchester.
Gabions were chosen because the services are in an area of ancient woodland and local conservation groups were keen to preserve the natural environ- ment. Structures such as reinforced concrete retaining walls were therefore ruled out at a public inquiry. The chosen retaining system also had to have a minimum design life of 60 years and be built within the footprint of the existing highway.
The up to 6m high walls are 340m long, running alongside the southbound on-slip and the northbound offslip access roads. An additional section of Green Terramesh soil reinforcement supports the southbound off-slip.
The walls were designed by consultant Woods Warren, working for the Highways Agency. Main contractor PJ Carey carried out excavation and installed the Green Terramesh. Gabion installation was subcontracted to PC Construction.
All lanes of both carriageways of the M3 remained open during the construction phase, with the chalk slopes cut during the day and the gabion