Slope Stabilisation on the A465 Heads of the Valleys Section 2

Overview

South Wales is one of the most complex areas in the UK for geotechnical works, with numerous geological hazards, anthropogenic hazards and environmental challenges. These complexities make both the design and installation of geotechnical works challenging, particularly where the A465 passes through the steep sided valley of the Clydach Gorge.

The A465 Heads of the Valleys Section 2 project focused on the 8km stretch of road from Gilwern to Brynmawr, and forms part of a larger Welsh Government scheme to install a dual carriageway over a total of 40km of the A465 between Hirwaun and Abergavenny.

Costain began construction on site in January 2015, with BAM Ritchies becoming involved in 2016. Over the course of the next year, BAM Ritchies installed over 3,700 soil nails and rock bolts across three separate slopes on the project. Ground conditions quickly proved complex, with variable levels of glacial till overlying rockhead and boulders within the till causing complications during excavation.

The presentation will highlight the combination of drilling methods and techniques that BAM Ritchies utilised to overcome the challenges and successfully deliver the works which also included the installation of Deltax, Greenax & Maccaferri meshes.