Central Alliance brings ground investigation expertise to Highland Enhancement Programme for BAM Nuttall

Ground investigation

Central Alliance brings ground investigation expertise to Highland Enhancement Programme for BAM Nuttall

Extensive programme of both on and off-track ground investigation works along the Aberdeen to Inverurie route

Project Background

Central Alliance were commissioned by BAM Nuttall to carry out ground investigation works along the Highland main line route between Aberdeen and Inverurie as part of the Highland Enhancement Programme (HEPS). Works included an extensive programme of both on and off-track works comprising rotary drilling, cable percussive boreholes, automatic ballast sampling, dynamic sampling and trial pitting.

Project Scope

Undertaking this work at this location required particular attention to fatigue management and staff wellbeing. Our approach ensured that all our staff were accommodated near to the site with travelling carefully managed. Our management of fatigue was strengthened by the fact that between January and June 2015, our SHEQ Director was seconded to Network Rail to project manage their fatigue programme, as summarised and published in Network Rail’s own Network magazine, as illustrated.

This insight and experience has been continually brought back to Central Alliance so that we have an extremely proactive approach with regards to fatigue. We manage working hours to ensure that staff do not become mentally or physically unfit due to fatigue or are exposed to stress due to working long hours.

Project Deliverables

Central Alliance and BAM Nuttall worked collaboratively for the duration of this project, for example, for on track positions CA installed pressure transducers to reduce the possession requirements for completing on-track monitoring. Structure investigation comprising slit trenching for services was completed by BAM Nuttall with CA providing expertise for logging and reporting for inclusion in our Factual Report.

Site visits with the contractor, consultant and client were essential to ensure that the works were completed safely in a difficult environment with no disruption to trains. Using our bespoke, modular dynamic sampling rig it was possible to provide both Standard Penetration Test’s and undisturbed U70 samples in areas where hand held equipment had been specified due to access constraints.

As part of the ground investigation works instrumentation was installed into the boreholes standpipes and piezometers. All instruments were read during the fieldworks and subsequently for over 12 months. Central Alliance’s early contractor involvement and input to the client allowed for the inclusion of pressure transducers for on-track monitoring providing significant cost savings to the client by reducing the number of possessions required for monitoring from 36 to 6 whilst also providing quantative groundwater records

The works comprised the completion of on and off track works 219 window sample and dynamic probe boreholes, 142 cable percussive boreholes, 11 on track rotary cored boreholes, 8 hand augers and installation of 100 groundwater / ground gas monitoring installations. The works were completed over a 12 month duration and were fully supervised by Geo-Environmental engineers supplied by Central Alliance. Extensive suites of Chemical and Geotechnical laboratory testing (value over £100k) was arranged by CA.

CA worked in conjunction and collaboration with BAM Ritchies on the high mileage section of the scheme, sharing equipment, expertise and occasionally resources in order to deliver works successfully.

Project Benefits

The project was highly successful with an exemplary Health and Safety record.