Most practitioners and engineers who currently design walls and slopes still prefer to work with high quality and free draining granular fills as backfill. However, as we move towards a Net Zero world, engineers can make a significant difference and act to help reduce carbon emissions within projects and therefore address climate change.
Infrastructures required to get to Net Zero need to be resilient and financeable. Thus, consider marginal fills or recycled spoil generated as part of construction activities shall become the new normal for the creation of walls and slopes. Marginal fills typically have high silt and/or clay contents which, when loaded, have the potential to generate excess pore water pressures in the structural backfill. Poor drainage in the structural fill reduces the available strength of the fill, thus reducing the bond between the fill and the geogrid reinforcement. Therefore, to use marginal fill efficiently, adequate drainage must be provided in the reinforced soil structure. By using composite able to provide reinforcement and drainage into a geostrip, sustainable and environmentally friendly slopes and walls can be designed and constructed.
Significant monetary and environmental savings can be achieved on construction projects by utilizing excavated site won marginal fills in earthworks, especially as the structural fill in reinforced soil structures. Concerns around the generation of excess pore pressures in marginal fills during construction are often cited as reason not to use these soils in this application. Experience have shown that a wide range of marginal fills, going from colliery spoil to made ground to high plasticity clays, when combined with a draining geogrid have been successfully used in constructing reinforced soil structures to considerable height. Tailor System can help!
