Slope stabilisation using high-tensile stainless-steel wire mesh

Slope stabilisation systems with meshes made of high-tensile steel wire have been in use for 20 years and have proven to be reliable systems on loose rock and soil slopes. The optimization of the nailing pattern thanks to the high load bearing capacity of the system permits a reduction of the overall costs and represents an economical solution as well as an ecological solution. The expected service life with regards to corrosion depends, in addition to the corrosion protection used, on the environmental conditions and the corresponding chemical wear. The definition of aggressive corrosive environments for slope stabilisation projects are for example: coastlines by the sea, aggressive ground (low pH-value, sulphur content) and roads with de-icing (salt). If the micro-climatic conditions on site are known, systems made of stainless steel can be installed to counteract the aggressiveness and keep up a long service life. Stainless steel is a steel alloy, with a minimum of 10.5% chromium and less than 1.2% carbon content. The chromium produces a thin layer of oxide on the surface of the steel known as the 'passive layer'. This prevents any further corrosion of the surface. In this contribution the pilot project for stainless steel-based slope stabilisation is presented, which has been installed 14 years ago in an aggressive environment, along the coastline in the UK. It was installed in 2007, with a stainless high-tensile steel wire mesh. Not only does the slope stabilisation mesh have to be made out of stainless steel, the additional components have to present the same protection to avoid the phenomenon of bi-metallic corrosion. Therefore, the nails, spike plates and press claws were as well made of stainless steel. After fourteen years, the slope is still undisturbed and the material in good conditions although exposed constantly to the sea breeze.