Client

Barratt Homes

Value

£3.99 million

Duration

50 Weeks

Project Summary

• Excavation and Compaction of 295,000 m3 of near surface soils

• Removal of 16,000m3 of reinforced concrete slabs and  underground obstructions

• Bioremediation of Hydrocarbon Contaminated Material

• Crushing and Screening of reinforced concrete to produce Type 1 Subbase and Pipe Bedding

• Construction Piled Retaining Wall, Outfalls and Drainage

On the site of the historic former Mabey Shipyard factory Barratt Homes are constructing 345 new houses. In order to facilitate the construction of the housing development the site required Remediation both Geotechnically and Geoenvironmentally.

Prior to any other works staring on site the areas contaminated with Knotweed were identified, excavated and placed in an on site burial cell outside the development area. The site was almost entirely covered by concrete hardstandings and due to the industrial nature of the site significant underground concrete obstructions were present  that required removal and crushing to provide recycled aggregate for the future development. Once the hardstanding and obstructions were removed the site was excavated and recompacted to a depth of 2.5m to provide a development platform for the new housing. Extensive plate load testing was undertaken by the Geotechnical Consulting Engineer to demonstrate compliance with the performance specification.

As turn and compaction works progressed any contamination soil from the former industrial use was excavated and treated. Primary contaminants of concern were hydrocarbons. Following the deployment of Neal Remediations mobile treatment permit excavated contaminated soils were formed in to bio piles, the piles were covered to control humidity and  aerated to stimulate the breakdown of the contaminants.

In addition to the Remediation works primary infrastructure was constructed for the scheme including piled retaining walls and outfall drainage.