A465 Heads of the Valley

Overview

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 for 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.

The scheme will improve road safety, reliability and travel times and includes extensive provision for active travel along the route. It is critical to the economic and social regeneration of the Heads of the Valleys area. 

Our role

Ayesa 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. Ayesa analysed the cross sections to provide an assessment of the likely movements to ensure that the road remained serviceable. Ayesa 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.