As part of the improvements to the A75 Annan bypass in Scotland, a 40m long retaining wall was constructed using a prototype anchored earth system developed at the Transport and Road Research Laboratory (now the Transport Research Laboratory). The wall had a maximum retained height of 7m, and carried a slip road to a bridge over the bypass. The system comprised 1.0m diameter half-disc concrete anchors, connected to window box facing units by continuous loops of polymeric strap. A clayey till that outcropped in a cutting close to the site of the wall was used as backfill. Details of the site, the design and relative costs of different types of retaining wall, and the construction and performance of the wall are given in this report. The results of a comprehensive series of laboratory tests and a field monitoring programme are also presented and discussed. (A)
Abstract