MacMat R1 and DT Mesh were used in a combined solution
A coastal road in Melilla, Spain, needed to be protected from both erosion and rockfall hazards. The mitigation solution we proposed used our erosion control geomat MacMat R1 to reinforce the soil and DT steel wire mesh to contain falling rock and gravel.
The Spanish Ministry of Environment launched a scheme to protect a coastal road from slope erosion in the Municipality of Melilla. Delfi Vertical was awarded the project and contacted us to offer proposals to solve the stability problems.
The presence of different materials on the slope required the use of a combined solution. We suggested the use of three products:
- MacMat R1 Steel for the upper part of the slope where the soil was unstable and where the erosion problem was more evident;
- Double Twisted (DT) wire mesh with GalMac 4R coating on the vertical rock face to prevent small rocks from falling on the road;
- DT wire mesh with PVC coating on the lower part of the slope, to contain rock and gravel.
MacMat R1 Steel is a 3-dimensional geomat made from polypropylene fibres and reinforced with a double twisted steel wire mesh with GalMac zinc-aluminium galvanising for greater protection. The geomat protects the soil from the direct impact of the rain and therefore improves the growth of vegetation compared to an unprotected slope. The double-twist steel wire mesh reinforcement is integral within the 3-d geomat; this increases the punch and tensile resistance of the product improves the slope stability by limiting slumping of the slope. Also on this project, a layer of topsoil was brushed into the 3-d matrix of the geomat which was then hydroseeded. Autochthonous plants were also planted in different areas of the slope after the installation of the MacMat. This regime will vegetate the slope and the plant roots will be reinforced by the MacMat R, making them and the slope more resistant to future erosion.
Beneath this sloped area, the ground steepened to almost vertical. In this case, it would not have been possible to establish vegetation and the problem was the prevent rockfalls from the face. Our double twist “DT” steel wire hexagonal mesh with a GalMac 4R zinc-aluminium galvanising was installed to protect the vertical rock face beneath the slope and connect it to the MacMat R above.
The lower part of the slope, beneath the road level and continuing down to the sea and along a coastline made of rock and gravel, was secured with DT wire mesh with an additional polymer coating. Given the exposure conditions, a mesh (even heavily galvanised) which does not have an additional polymer coated is unsuited to these aggressive environments.
For this project, we provided:
- 6,100 m² of MacMat R1
- 5,600 m² of GalMac 4R coated Double Twist “DT” hexagonal steel wire mesh
- 3,000 m² of GalMac 4R + Polymer Double Twist “DT” hexagonal steel wire mesh
For more technical information, please download our case history.