A465 Widening: Temporary Rock Face Stabilisation

Client

Costain

Location

Brynmawr

Value

£150,000

The major realignment and widening of the A465 Heads of the Valley Road between Brynmawr and Gilwern required large rock cuttings. Quantum were appointed to provide temporary support in the form of rock bolts and support cabling, in order to prevent large blocks of massively bedded quartzitic sandstone toppling into the work area. The outcrop was located some 5m above the working platform, adjacent to a busy haul road.

Quantum’s solution involved:

  • Rock Bolting: Installation of 100 3m long 40mm diameter GEWI bar dowels in 100mm diameter open holes drilled using one of our TEI Hem 560 drill masts. Access to the BH location for installation and grouting was provided by a 360 degree tracked MEWP.
  • Rockfall Netting: Placing and securing 1300 sq. metres of Geobrugg Deltax rock netting.
  • Support Cabling: Placing and securing circa 300m of 16mm galvanised wire rope.