Coastal landslip stabilisation - The Leas, Folkestone

REQUIREMENT

As a result of heavy rainfall saturating the sandy soils, a surface landslip occurred along a 75m stretch of The Leas in Folkestone, a steeply sloping coastal area.

Shepway District Council required the ground to be rapidly and cost-effectively stabilised to prevent any further erosion and appointed Shepway Contract Services who chose mechanical ground anchors to secure plastic coated wire meshing installed over turf to prevent further movement of the coastal embankment.

SOLUTION

Shepway Contract Services first had to clear the section of uprooted bushes and trees and level the 45m high embankment, to the same gradient as the surrounding terrain, before covering the area with turf to help bind the surface.

Coated wire mesh was placed over the slope and secured with mechanical ground anchors with stainless steel wire tendons. Using hand-held air breakers, over 1200 anchors were installed to depths of between 1.5m and 2.5m and locked into position.

The mechanical ground anchors were set to a proof load of 10kN and the wire tendons were then connected to 120mm high density geogrid discs which held the mesh in position.