SCA Group/Osbourne
Services Supplied on this Project:
- Geotechnical Ground Investigation
- Ground Water Monitoring
Key Considerations:
- Health and safety plans
- Public safety
- Stakeholder communications
- Utility scanning
- Traffic management
- Working on slopes
The Project
Geo-Environmental Services Limited was instructed by SCA Group on behalf of Osbourne to undertake a Geotechnical Assessment at Three Arch Cutting near to Sherbourne in Dorset. Emergency works had been undertaken which involved the removal of failed material from the running line and removal of dangerous trees. A temporary speed restriction had been imposed and subsequently a toe wall of ballast bags was constructed to remove the speed. It was proposed to remove the ballast bags and construct a permanent toe wall, with associated crest and track drainage works and removal of contaminated ballast. As such, the objectives were to obtain information on ground conditions in support of the slope stability assessment for the cutting and aid the
design of the proposed upgrade to the drainage.
Services Provided
- Provision of a Construction Phase Plan and RAMS pack specific to the proposed investigation and attendance of a PTS qualified Geo‐Environmental Engineer.
- Construction of 1 No. rotary borehole constructed with a Comacchio 305 multi-purpose drilling rig using dynamic sampling techniques to depths of 10.0m
to determine ground conditions at depth from the crest to the toe cuttings. - Standard Penetration Tests (SPTs) were undertaken within the borehole at 1.50m intervals to provide additional data to inform and support geotechnical
assessment. - Two groundwater monitoring wells were installed within BH1 upon completion of drilling to depths of 9.0m and 4.0m.
- In order to characterise the general chemical quality of the soils at shallow depth, two samples of shallow soils were submitted to a UKAS accredited
laboratory for analysis. - Provision of a Factual Report detailing the encountered ground and groundwater conditions and the results of in‐situ and laboratory base testing. The report
would be delivered in electronic format only.
Benefits
This was a rapid reaction project and we were required to mobilise to the site very quickly, something we could cope with because of our robust supply chain management and electronic resource management platform. A further difficulty on this project was that the borehole was undertaken at the crest of the slope with a road running within metres of the plant. This required negotiations with the local Council, as well as Network Rail, Osbournes and Arcadis, the latter of who were the lead consultant on this project. Whilst in this instance Arcadis undertook the slope stability and analysis themselves, Geo-Environmental have the in-house experience and the software to undertake slope stability assessments and designs in our own right and have done so on numerous projects in the highways, housing and utility sectors. Our staff include Chartered Engineers, Chartered Geologists, Chartered Environmentalists and Chartered Scientists.