We were about to commence our second phase of project work on the reinforced soil walls at the toe of the existing A13/A1014 interchange embankment when it became evident that the necessary excavation to provide sufficient space for this structure would affect the stability of the existing highway slopes.
Following consultation with Civil Engineering Principle Contractor Murphy and Atkins Consulting Engineers, we put forward a proposal to design and project manage a pattern of soil nails and structural mesh facing in order to provide temporary earthworks support to the cut slopes prior to the installation of the reinforced soil bank at the toe of the new northbound slip road extension.
This approach was accepted and approved with the works taking place over two phases each of 1 week duration where over 300 nails and 750 sqm of mesh facing were installed with benefits to programming, speed of installation and economies of construction being realised. Further, the current permanent works design for the embankment could be maintained without the need to submit to a lengthy design approval process for an alternative embankment retaining structure, and there were gains in the reinforced soil mass design too as improved soil parameters were obtained through supplementary window sampling and inspection of the cut slope prior to and during the installation of the nails.