2022 brought with it much carnage in the form of flooding in the Kwazulu Natal regions which saw Gabion Baskets doing our best to meet our obligations to clients and ensure that we get homes back to a safe environment for families. That being said, we thought we would touch a bit on the limits of mattresses on steep slopes :

When gabion mattresses are installed for hillside erosion and storm water control, a key question posed by designers is the limitation presented by sharper gradients. Mattresses can be laid on slopes of 33 to 45 degrees. At higher gradients than this, the design alternative includes concrete retaining block walls. When designers push the limits above 45 degrees, there’s a risk of the entire gabion mattress losing its ground-contact adhesion and slipping down the slope, with ultimate loss of the structure. Slope slippage can be caused by slippery or hard materials that lower the grip. However, at working gradient tolerances, mattresses can be anchored to prevent this.

When it comes to installation, specialised training is a given, especially when preventing potential plier-related damage to PVC-coated mesh, which is an essential added feature for corrosive conditions, in conjunction with an underlying Galfan zincaluminium-treated wire.

Here, a classic wing wall gabion and mattress combination provides a highly effective erosion control structure on a steep-sloping koppie in Johannesburg: 75 mm x 100 mm aperture welded mesh was used to maximise the aesthetic effect, while geotextiles are being installed as a standard procedure to prevent soil loss.

Get hold of your Gabion Baskets specialist who will correctly advise you on the right mattress combination to ensure a lasting and safe structure is installed.