This cutting on the Micklefield to Leeds Station line had suffered rockfall historically, and a programme of works was devised to assess rockfall risk to the line and implement measures to reduce the rockfall risk within the cutting. CAN were enlisted to undertake the specialist work in the difficult access location.
To allow inspection of existing rock netting systems and rock faces, 19,000 sqm of vegetation and rock scaling was undertaken, removing scrub, trees and loose rock. Due to the steepness of the slopes, the need to remove loose material and the proximity to the line, these works were undertaken using rope access techniques during Saturday night possessions.
With the clearance completed and geotechnical inspection undertaken, around half of the cutting was deemed at high risk of future rockfall, and a passive rock netting system was specified. This required 366no. crest and toe bolts to be drilled up to 3m depth, and installation of 9700 sqm of passive rockfall netting over the cutting slopes.
The toe bolts were drilled during possession, utilising bespoke drill masts fitted to RRV’s to access the cutting. Compact 5T 360 mounted drill rigs were utilised along the narrow crest lines to install the top netting anchors, and A-frames were used to drill in the most difficult access areas.
The stumps from the cleared vegetation were treated to prevent regrowth destabilising the cutting, and the Maccaferri passive netting was installed and secured over the cutting slopes.
Duration: 18 weeks
Client: Story Rail
Location: Micklefield, Leeds