Tunnelling Ground Investigation Project of the Year

This award seeks to reward ground investigation that stands out for it’s innovation, quality, sustainability and value engineering as part of a tunnelling project between January 2023 and July 2024. Projects entered into this category should have elements within the design and delivery that focus on minimising risk from unexpected ground conditions.

BakerHicks, Morgan Sindall Engineering Solutions, National Grid
Grain to Tilbury Cable Tunnel FEED Study Ground Investigation

The project will replace the existing cable tunnel between Tilbury and Gravesend below the River Thames. An over-water and on-land ground investigation was designed and undertaken collaboratively between National Grid (Client), BakerHicks, Morgan Sindall Engineering Solutions and sub-contractors Fugro GeoServices and Socotec UK. This investigation provided risk reduction to the shafts and tunnel’s construction methodologies and designs. Key to the success of the investigation was active stakeholder management by BakerHicks and National Grid with stakeholders including the Environment Agency, Natural England, Metropolitan Police and the Ports of London and Tilbury. Working collaboratively with all parties allowed the scheme to adapt to external events and constraints to sequence the work and avoid disruption and delays. Using the information obtained from the high-quality rotary borehole drilling and logging, the depth of the tunnel and shafts were reduced by 5m, presenting value engineering savings to the scheme and saving 116.7 tonnes of CO2e.

Geoptic Infrastructure Investigations 
Muon imaging of rail tunnels  

Geoptic Infrastructure Investigations Ltd (Geoptic) has pioneered the application of muon tomography - a novel imaging technique - to vital ground investigations on Network Rail. Muon tomography works in a similar way to an X-ray and is sensitive to density variations in objects that are otherwise difficult to access. The muons are created naturally and so are freely available and can easily penetrate many tens of metres of rock. The muon imaging technique is also non-invasive and so no contact with any ground infrastructure is needed in order for density variations to be mapped and imaged. The technique has been successfully applied in a programme of work spanning a dozen rail tunnels on Network Rail's Wales and Western region. Using muon tomography, high fidelity 3D images of voiding and hidden shafts have been successfully created, non-invasively, with significant reduction to H&S concerns when compared, e.g. with invasive drilling programmes.

Mott MacDonald
The Ohio River Tunnel

Many underground projects are benefiting from the value that digital field tools provide. The implementation of a Digital Field Tracking System (DFTS) for the Ohio River Tunnel Geotechnical Investigation Program (GIP) showcases these benefits. The DFTS standardized the QC process and enhanced efficiency in every aspect of the GIP. Built with Microsoft Power Apps/Automate and utilizing a single cloud-based data source, the DFTS offers protection from data loss and reduces errors related to data transfers. The customizable nature of Power Apps/Automate allows for the DFTS to be programmed according to specific project needs, giving it a distinct advantage over commercially available software options

Soiltech India Private 
Geotechnical Investigation for Construction of Underground Cavern

The project encompassed a comprehensive array of investigations to thoroughly assess ground conditions and geological properties for upcoming cavern development. These included: Drilling both vertical and inclined boreholes up to depths of 200 meters. Conducting a 24-channel Seismic Refraction Tomography over a span of 3000 meters. Performing Electric Resistivity Tomography across the same distance. Executing Hydraulic Fracturing Tests to determine In-situ Stress conditions. Conducting Electrical Logging in boreholes, alongside measurements of Natural Gamma and temperature. Utilizing Acoustic Televiewer technology to inspect borehole walls. Implementing Double Sonic Logging to analyze rock properties and structures.

SSE Renewables, Strabag, Fugro, Stantec, Cowi and BGS
Coire Glas Ground Investigation

SSE Renewables has invested >£100M in the proposed Coire Glas hydro pumped storage scheme with a significant proportion assigned to ground investigation. Coire Glas will be the largest such scheme to be developed in the UK for over 40 years. The GI, designed and supervised by Stantec/COWI, comprised: -1.2km exploratory tunnel delivered by STRABAG UK. -Wider Site GI delivered by Fugro with 1,775m of boreholes including one 650m deep. BGS provided a watching brief across the GI due to the complexity of ground conditions in the Great Glen of Scotland. The team’s goal was to minimise the risk from unexpected ground conditions through collection of high-quality data to be used in Main Works design and in development of the project’s Geotechnical Baseline Report. The team overcame significant access challenges including limited existing infrastructure and rugged terrain. Effective communication and collaboration resulted in the team delivering outstanding results for the project.