A465 Heads of the Valley
The A465 Heads of the Valleys route cuts across the top of the south Wales valleys, between the southern fringes of the Brecon Beacons National Park and the industrial centres of Newport, Cardiff and Swansea to the south. The road passes through some stunning scenery and while the hilly terrain is certainly dramatic, its undulating route has called for extensive earthworks. To widen the road, it has been necessary in several locations to cut into the adjacent hillside, significantly steepening the road boundary which then needs reinforcement to stabilise the ground and remove the risk of collapse.
ByrneLooby is the temporary works designer for Costain, providing the design of soil nails and temporary netting to support temporary slopes beneath the existing road to enable the construction of the permanent works. ByrneLooby analysed the cross sections to provide an assessment of the likely movements to ensure that the road remained serviceable. ByrneLooby defined the monitoring strategy and procedure to enable the movements to be checked to confirm that the temporary works were acting in accordance with the design.