The Sustainability category required entrants to demonstrate an innovative, unusual or cutting-edge approach to environmental and sustainability issues on a geotechnical project.
The shortlisted entries outlined benefits to all three pillars of sustainability – environmental, social and economic; an involvement with others in the supply chain; and the potential for the approach to be rolled out to other schemes or projects.
Aecom and VolkerFitzpatrick – Daventry International Rail Freight Terminal (DIRFT)
As part of the DIRFT scheme, a raised platform, 9m above existing ground level, with new railway lines, sidings and intermodal transfer facility was constructed. The project involved a sustainable earthworks solution involving the improvement and re-use of 250,000m3 of site-won materials to construct the engineered platform for the intermodal facility. This approach resulted in reduced costs of importing fill and eliminating the cost of removing alluvial soils and disposal of otherwise unacceptable excavation materials to landfill.
Bachy Soletanche with Costain and Crossrail – Sol Thread – threaded rotary bored piles
The aim of this technique was the reduction of material use in rotary piles through the creation of a threaded rotary bored pile in London Clay. This patented pile consists of a central core, with a helical thread formed around this, increasing the effective geotechnical diameter of the pile by 150mm. The construction of the thread increases the pile capacity compared to a normal straight shafted pile. This shortens the pile length needed, further reducing materials and spoil.
Canary Wharf Contractors, Arup and Concept Site Investigations – Reuse of piled foundations for the redevelopment of Southbank Place, London
The site investigation for the 12-storey wing building of the Shell Centre on London’s South Bank involved a novel approach based on ISO2859 to determine the number of piles that should be investigated to demonstrate their adequacy for re-use. The project sets the benchmark for a risk-based practical approach to the investigation of existing foundations which can bring considerable savings and environmental and social benefits to projects.
National Grid – In-situ remediation of Beckton Gasholder No. 1
Gasholder No.1, which lies within the former Beckton Gasworks site, was known to contain residual tar (NAPLs). There was a need to reduce environmental liabilities associated with the tank and develop a remediation solution. The approach combined initial stage recovery techniques to remove as much primary source as possible from within the tank, with in-situ grouting techniques to enhance recovery of NAPLs and encapsulate remaining material into a monolithic block. By filling void spaces in the tank with grout, the tar emulsions were forced out of the tank into recovery wells.
Power Cem – Wrightington Hospital, Wigan
The scheme involves a solution for a sustainable access, parking, materials storage and temporary accommodation compound for Wrightington Hospital. A costing exercise established that stabilising the soils with Road Cem would be faster and cheaper than a stone mat. Figures published by the Vinci Construction/Sir Robert McAlpine consortium showed that a saving of 20% was made in construction costs for the works and the number of vehicle movements to and from the site has been reduced, together with a reduction in carbon emissions of 60%.
United Utilities – Discontinuance: Returning Hurst Reservoir to the landscape
United Utilities (UU) sustainable long-term solution for Hurst Impounding Reservoir Discontinuance was achieved through removal of the dam and restoring Hurst Brook to its natural course, using material from the embankment to re-profile the valley. Complex stakeholder involvement and buy-in was key to completing the project successfully.
VHE Construction, Aecom, Provectus and Clyde Gateway – Shawfield Remediation, Glasgow
Clyde Gateway has embarked on the largest regeneration scheme in Scotland, designed to drive forward an investment programme over a 20-year period. The remediation of the Phase 1 site at Shawfield required close collaboration across the supply chain to deliver the project using an innovative process for the treatment of hexavalent chromium at depth and the recycling and re-use of existing demolition materials. It is calculated that this will result in a saving of 800t of CO2 emissions.
West Dorset District Council, CH2M Hill, Balfour Beatty Construction Services UK and Aecom – Lyme Regis Environmental Improvements (Phase IV)
The project aims to address the landslide threat to the east flank of Lyme Regis through the construction of a new seawall to replace an existing dilapidated wall; slope stabilisation works; extensive landscaping; and environmental mitigation works. The scheme has a design life of 60 years and aims to provide long-term protection of 480 properties, the main road and associated land and infrastructure.