Extension of Five Nursery Schools in Birmingham (Government Sure Start Initiative)

Birmingham City Council (Education Dept)

Geo Environmental Group (GEG) where commissioned by Birmingham City Council Urban Design (BCC UD) to undertake a geotechnical and environmental assessment of number of sites in Birmingham in order to enable foundation design and satisfy planning requirements for the construction of extensions to five nursery schools.

Five individual Phase I desk study reports were undertaken providing site history, geology, hydrology and flood risk, hydrogeology, landfill /mining and preliminary risk assessment. Further information on the history of the site was provided by BCC UD. These were followed by Phase II intrusive investigation consisting of window sampled boreholes with associated chemical sampling/analysis of soils/groundwater and in-situ/ex-situ geotechnical testing. Hand dug pits were also excavated adjacent to the existing school buildings to expose the existing foundations. Phase II reports for each school detailed environmental risk for soils and groundwater, any remedial requirements and foundation design.

Only one of the schools required limited remediation due to elevated concentrations of PAH.
Traditional shallow strip foundations were determined as being suitable for two of the extensions, but due to softened natural clays and deep made ground, strip foundations were unsuitable for the remaining two schools. Further complications were the close location of mature trees and the restriction placed on vibration. Therefore, driven and vibro-piles were considered unsuitable, and CFA bored, cast in-situ or mini piles were recommended. All works were overseen by BCC UD.