Case Study – Geotechnical Earthworks Consultancy Services

Southern Testing provide geotechnical consultancy services to Local Authorities in relation to Section 38 and Section 278 agreements on Developer Lead Infrastructure Schemes.

The work undertaken by Southern Testing includes;

• The detailed review of geotechnical design reports, earthworks specification appendices, geotechnical sections of structure AIP’s and construction drawings.
• Attendance of progress meetings during the construction phase, with the Developer, the Principal Designer and the Principal Contractor.
• Undertaking site inspections and liaising with the Principal Contractor and the Engineers Representative during the construction phase.
• Undertaking walkover surveys to identify snagging items and final works inspections.
• Review of the geotechnical feedback / validation reports.

Recent projects have included; Three interlinked earthworks projects at South Broadbridge Heath, namely; the A24 Grade Separated Junction, the East West A24 Link Road and the A24 Access Embankment.

These schemes involved the construction of geogrid reinforced highway embankments up to 9m in height and required around 170,000 m3 of Class 2 fill material with side slopes of up to 1v: 2h.  A number of structures were also constructed including a single span composite concrete bridge over the A24 dual carriageway which is supported on reinforced soil abutments.

The Bognor Northern Relief Road which involved the construction of an 11 span, 0.5km long viaduct constructed over the Bognor to Barnham railway line and the Lidsey Rife River, the construction of around 1km of highway embankments and a number of geogrid reinforced noise bunds.

North Bersted Northern Relief Road which involved the construction of around 2.2km of highway embankment, 2m to 3m in height, over low strength and compressible ground.  The solution adopted by the Designer involved installing prefabricated vertical drains to accelerate the rate of consolidation settlement, surcharging and monitoring the performance of the embankment with a number of geotechnical instruments both during and after construction.

If you would like further information about our geotechnical consultancy service or any of the other services that we offer, then please don’t hesitate to contact us. You can get in touch with a member of the team by completing our contact form below, or alternatively by contacting one of our offices.