Weathering of one of the rock faces and the upper soil slope above it to at this former quarry in Crich was causing progressively failure of land at the crest, putting the gardens of properties above at risk. The quarry owner had developed a remedial works design to stabilise the upper rock face and slope and CAN were contracted to undertake the build of the solution.
The remedial works called for removing failed soil material and reprofiling the upper slope to a slacker angle, before installing soil nails and netting to stabilise the slope permanently, with topsoiling/reseeding of the face carried out to encourage revegetation. A row of gabion baskets would then be installed along the crest to re-establish prior ground levels and allow reinstatement of the residential garden upon completion.
With the works taking place at height on the upper reaches of a tall cliff, the only access was through a residential property and through the back garden, where belay points for rope access were established to enable operatives to abseil down over the face to undertake the regrading work. Upper rows of soil nails were drilled using a compact 360 mounted drill rig, with specialist A-frame drill rigs used to install the remainder of the 184 soil nails up to 12m deep into the face.
The slope was then covered in a combined erosion matting and steel netting, with topsoil brushed into the erosion matting to form a medium for vegetation to re-establish, neatly hiding the completed works from view. The gabions were constructed in situ at the crest and a new fence installed, and the garden was returfed and fully reinstated.
Duration: 22 weeks
Client: Mitie
Location: Crich, Matlock