Bishops Court Quarry – Exeter

Bishops Court Quarry – Exeter

From the late 19th century, the former Bishops Court Quarry (just off junction 30 of the M5) operated as an opencast site for the extraction of aeolian sands. After the late 1990s, the site was backfilled with around 300,000m³ of sand arisings from surrounding infrastructure works - up to 30m above the former quarry base. When Harrow Estates acquired the site and proposed with Redrow Homes South West to redevelop it for 190 homes, we were asked by remediation contractors VertaseFLI to review the earthworks tender documents. These had been issued for the re-profiling of the site, with treatment via dynamic compaction to create a development platform suitable for shallow foundations.
 
After critically assessing the geotechnical data and the proposed methodology, our team of specialist geotechnical and ground engineers redesigned the earthwork strategy - taking a mainly conventional excavation and compaction approach with localised use of high energy impact compaction to improve deeper areas of fill.
 
The scheme successfully received NHBC regulatory approval within four weeks of submitting our validation report. Our revised approach realised cost savings not only on the remediation earthworks, but also on the eventual foundations used for the residential units.