Earl Shilton Treatment Works
We were approached by Severn Trent’s contractor to discuss the creation of site access and the installation of a proposed working platform at the sewage treatment works at Earl Shilton, southwest of Leicester. The works were being developed to increase its waste processing capacity. The proposed plant for the site works required temporary works access as well as a working platform for the concrete pump and hydraulic (Kobelco CKE700) crawler crane. The traditional approach to working platform design is to use a BR470 design methodology as suggested by BRE – Working Platforms for Tracked Plant (2004). Instead, our technical team proposed a load-spread analysis using TerraGrid Pro Biaxial geogrid. This meant the working platform thickness could be reduced by a further 40% compared to BR470. Although the application area was not large, the benefit was significant when operating in such confined spaces. Reducing the resources required can have a very positive impact on such a restricted site, not only reducing costs but also minimising the contractor’s construction programme and overheads. 
Within a well-managed time frame, the technical team was able to value-engineer the traditional approach to platform construction. With tight site constraints and limited resources, the impact on value engineering the temporary working platform was a 40% cost reduction, after an allowance for the cost of the geogrids. Throughout the project, we assisted with coordinating the proposals, collaborating with the full supply chain, which included Noble Works as the scheme designer and Stantec as the Tier 1 contractor. TerraGrid Pro Biaxial geogrid from Wrekin is a large-aperture polypropylene geogrid used to reinforce the ballast layer, reducing ballast settlement and subsequent maintenance interventions following ballast renewal. TerraGrid Pro delivers ground stabilisation under roads, railways (we have a Network Rail certificate of acceptance for TerraGrid Pro Biaxial Grid) and paved areas. Employed in single or multilayers, the tough platform created provides tremendous load dispersal, allowing previously weak soils to be reclaimed for a wide range of uses, including, as at Earl Shilton, for access roads and platforms. When granular particles are compacted over TerraGrid Pro Biaxial grids, they partially penetrate the apertures and project through them to create a strong, positive interlock. The load-dispersal effect from the interlocking mechanism increases shear resistance in the soil, improving compaction and allowing the sub-base thickness to be reduced, ultimately cutting construction costs and time. |
