Geobear provided urgent works to stabilise the bank of the Grand Western Canal running through Tiverton in the UK. The embankment had become unstable due to burrowing animals and Devon District Council needed an urgent solution.
The Grand Western Canal runs across the South West of the UK and a routine inspection raised alarms on a section of the embankment. Burrowing badgers created voiding in the embankment, clearly visible to the naked eye. The local council required a solution that could fill the voids created by the badgers and stabilise the bank. There was a significant chance that the failure of the bank would lead to the canal wall breaking and pose a flood risk to the local houses.
Difficulty with site access meant there were a limited number of solutions open to Devon DC. A cement-based material would put additional weight on the site weakening the deep soils and could lead to ruptures. Additionally, heavy plant equipment would not be able to access the site without significant enabling works.
We proposed a solution to fill the voids with one of our geopolymer materials.
The first step in the process was to carefully remove all the badgers from the site and relocated them to a new purpose-built home. Once the local council had completed the relocation, Geobear could inject expansive material into the site to completely fill all the voids and ensure badgers or other burrowing animals could not access the ground.
The geopolymer material comprises two components and is introduced to the site as a liquid. The two components react in the ground and form an expansive resin fill material. Using an engineered design, we injected the material to depths of four metres across a 20 metre stretch of the bank. The material completely filled the voids and was verified by visual inspection.
The Geobear solution was ideal for this scheme as the fill material is lightweight and adds minimal load to the existing site. Furthermore, a cementitious grout could have a negative environmental impact should the material find a path into the water, with significant fines pending from the Environment Agency.
Our geopolymer material has been subjected to leaching tests by Stantec; the results highlight that there would be no discernible presence of hazardous substances or non-hazardous pollutants if geopolymer entered groundwater.
After we filled the voids, the client needed to cut into the bank to ensure it retained a 45-degree angle. As the geopolymer material is easy to extract, the client could make the necessary ground alterations to ensure this angle was achieved. Cement-based solutions would require drilled excavation, something difficult to accomplish on the site.
Geopolymer material can be pumped from over 50 metres away; therefore, no enabling works were required for Geobear to deliver the solution.