A465 Dualling Brynmawr to Gilwern Section


Costain Group


A465 Heads of the Valleys



Quantum have carried out a number of services for Principal Contractor Costain on this major Welsh Government and European funded highways scheme. The overall scheme is to dual the existing A465 from Brynmawr to Gilwern which runs through the Clydach Gorge.

Quantum commenced ground investigation works in February 2015 and will continue into 2017, undertaking works including ground investigation, slope stabilisation, ground stabilisation and ground monitoring works.

GI works carried out to date include:

  • In excess of 150 rotary and cable percussive boreholes to various depths for geotechnical, environmental and mining investigation purposes.
  • Machine excavated trials pits for contaminant land and geotechnical assessment including asbestos investigation, with appropriate Quantum risk management and methodologies in place.
  • Installation of groundwater and land gas monitoring standpipes, inclinometers and heavy duty vibrating wire piezometers.
  • Geophysical televiewer and acoustic logging of selected deep boreholes.
  • Geophysical seismic survey including rope access surveying.
  • Laboratory testing and post-fieldwork monitoring.
  • Reporting