CAN Geotechnical (an RSK company) is approaching the end of slope and rock face stabilisation work for the A465 Heads of the Valleys Road section 2 scheme, which runs between Gilwern and Brynmawr, South Wales. A case study of their work has been published by Construction Update, online and in its magazine.
“The A465 Heads of the Valleys Road runs across the northern edge of industrial South Wales, providing an east-west connection between west and east Wales,” the article begins. “The Welsh Government announced an ambitious plan to improve this main arterial trunk road, which in turn is critical in the social and economic regeneration of the area, by upgrading the road to a full dual carriageway along its entire length. For ease of delivery, Welsh Government have split the projects into a number of sections; section 1 (Abergavenny to Gilwern), section 2 (Gilwern and Brynmawr), section 3 (Brynmawr to Tredegar), section 4 (Tredegar to Dowlais), Section 5 (Dowlais to A470) and Section 6 (the A470 junction to Hirwaun).”
In 2014, CAN conducted initial slope stabilisation works in one area of section 2, a three-lane carriageway that runs through hilly landscape on the edge of the Brecon Beacons National Park. Improving the road through this undulating terrain presented several challenges, including demanding “extensive earthworks and the removal of well over 1.2 million tonnes of material to facilitate the creation of the many cuttings and embankments along the route. In addition, many sections of the road required widening and it has therefore been necessary to cut into the adjacent hillside, resulting in the significant steepening of the road boundary, which brought about intrinsic destabilisation.” CAN’s brief was to stabilise these steepened slopes.