The conversion of the internal fire access roads: road no. 51 and 52 in the Forest District Cybinka

The plan was to perform construction works consisting in the conversion of the internal fire access roads: road no. 51, about 2.2km long and road no. 52 about 2.4km long. A soil-surfaced road, heavily deformed. The projected solutions included making a roadway of 3.5m using crushed stone aggregate, mechanically stabilised 0/31.5mm and a layer for soil stabilisation, made of a geonet with the tensile strength of 30/30kN/m in both directions.

The most important feature of the soil stabilisation with layers of aggregate stabilised with geonets is their ability to make the aggregate grains wedge between each other so that they produce the effect of lateral grain stabilisation. The more rigid the net structure that does not deform under the pressure of the aggregate, the better the ability to make the aggregate grains wedge between each other. Therefore, the construction of fire access roads in a forest requires bidirectional geonets with stiff monolithic knots and a square rib section with a high reduction coefficient of the aggregate layer thickness. Moreover, the uniformly distributed ribs of the mesh are made of top quality, uniform material.

The product in the form of the geonet E’GRID SX30/30 is perfect for underground structures as reinforcement (strengthening). The activation of the soil stabilisation function relies largely on the use of the forces resulting from the net ribs wedging between the aggregate, hence it is very important to choose the right grain size of the aggregate as compared to the mesh of the net.