MHB Consultants was appointed by QTS Group on behalf of Network Rail to provide geotechnical design services for the remediation of a soil and rock cutting near Maryburgh on the Inverness to Wick line. The aim of the scheme was to address instability due to saturated overburden and rock slump to the cess which presented a risk to the operational railway.
The site presented a number of constraints that shaped the design from the outset. Ecologically, the cutting sits in close proximity to the Lower River Conon SSSI and the Conon Islands Special Area of Conservation. At the crest, a public footpath and third-party landowners immediately beyond the Network Rail boundary ruled out land purchase and limited the available working width.
Slope stability analysis was carried out by MHB Consultants using GeoStudio’s Slope/W software, applying the Morgenstern-Price method and a partial factored approach in accordance with Eurocode 7 and BS8006.
The proposed solution comprised Geobrugg Tecco netting over the full soil and rock cutting face, pinned with rock anchors and soil nails, with light manual scaling of the rock face carried out during installation. This covered over 350 metres of earthworks.
The works were carried out successfully in Autumn 2025 under a series of Rules of the Route possessions. MHB Consultants also provided temporary works design in the form of a temporary Road Rail Access Point to help manage the limited night time working.
