The Southall Waterside development is a new neighbourhood alongside the Grand Union Canal in West London. The 45-hectare site, which housed the Southall Gasworks until 1973, will be accessed partly via the Western Access, which comprises a road over three new embankments and two integrated bridges, constructed within a 0.75 hectares area of brownfield land adjacent to the main site.
The earthworks will support a new carriageway with a designated cycle lane and footways that span Yeading Brook and the Grand Union Canal.
Due to poorer than anticipated ground conditions at this location, a basal reinforced embankment with a single horizontal layer of Paralink at existing ground level was required. The ground investigation identified a stratum of Made Ground in an old canal arm, which was removed as part of the ground remediation works. The area was excavated to a depth of between 1m and 1.5m below the original ground level and backfilled with lime-and-cement-stabilised Class 9E material.
A layer of crushed concrete was placed over this Class 9E material to create a solid platform. The typical height of the embankment through this section is around 4.0m but with a maximum height of up to 6.1m. The majority of the earthworks in this section were supported by concrete retaining walls along the extremities of the embankments. Paralink was laid for the Approach Embankment located to the east of the Grand Union Canal. The earthworks design was managed by CGL GCL while FN Conway installed the Paralink.
The embankment above the Paralink was constructed from a combination of Class 6N-IBAA at the core and Class 6N/6I immediately behind the retaining walls along the extremity of the embankment.
Due to its 120-year design life and the lowest partial factors in the market, Paralink was specified as the most suitable solution to increase the stability of the new proposed embankment built over soft soil.