This was a rehabilitation project where sections of a 100-year-old structure, Elan Valley Aqueduct (EVA), needed to be replaced. The EVA is an extremely crucial resource as it supplies water to Birmingham and its adjacent areas. There was a need to refurbish and modernize the aqueduct so that it can be preserved for the future. For this, a new conduit with a tunnel of 1.8 km long and 3.0 m diameter was proposed to be constructed. To construct the bypass conduit, a horizontal working platform was required to support the construction traffic, the 1000 ton crane used to assemble the Tunnel Boring Machine (TBM), and finally, the 150 ton TBM.

The solution consisted of a reinforced soil wall using StrataGrid™ 120 and 60 and site-won cohesive material as part of the cut-and-fill balance of the project.

On top of the reinforced soil wall, a reinforced working platform was constructed with selected granular material of 970 mm thickness and biaxial geogrid to distribute the load.

The use of StrataGrid™ helped in considerable cost savings compared to the conventional method of constructing the wall. It was an environment-friendly solution.