Read profiles of the initiatives shortlisted in the Sustainability Award category for the 2016 GE Awards
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.
Atkins, Volker Fitzpatrick, Network Rail: Risk management and observational design approach on Ashdon Way Railway Embankment, Basildon
Ashdon Way was one of 37 at risk embankments identified for remediation under CP5 on Network Rail’s Anglia Route Collaboration. The risk management and observational design approach (Roda) system was used to assess the site and Ashdon was the first to be dealt with in this way.
Conventional remediation using sheet piling and backfilling would have cost £8M but the Roda system focuses on simply fixing the worst affected areas using reduced design life solutions with less capital expenditure and continuing to monitor adjacent areas to the mitigation. Taking this approach reduced costs for remediation to £5.8M freeing up finances for other schemes.
CH2M: Safety, health and environment code of practice at Spring Gardens
Early adoption of the Environment Agency’s Safety, Health and Environmental Code of
Practice on the Spring Gardens project has helped the design and delivery of the work lead to numerous examples of good sustainable practice.
The project was needed to consolidate mine workings below an existing flood storage dam and sustainable practices applied to the work included use of the EA’s water extraction rights, bicycles for site access and reuse of excess grouting materials to undertake another project at the site rather to save costs and reduce waste. The main project was delivered on time and under budget.
Concrete Pipeline Systems Association: Circular precast concrete manhole base system
The concrete Pipeline Systems Association (CPSA) has developed a precast alternative to casting the base and connections for a manhole cover insitu, which it says improves quality and safety, while reducing time on site. The factory quality of the precast solution ensure water-tightness and prevents groundwater becoming contaminated, while removing the casting insitu reduces waste on site. The CPSA estimates that the precast alternative could reduce embodied carbon by 22,000t a year if all new manholes were constructed using this system.
Kier: EPS Road Embankment Construction, Windsor Road, Cardiff
Use of expanded polystyrene blocks enabled a 9m high embankment to support approach viaducts to a replacement bridge to be built within the project programme, at less cost than a conventional approach and with a lower carbon footprint too.
Kier has said that this project is the first time it has used polystyrene blocks on such a scale but the scheme would not have been able to meet the bridge replacement needed in the time demanded. The use of the blocks enabled the scheme to overcome the soft made ground without major foundations work or the need to import fill material.
London Underground, Cementation Skanska and Mott MacDonald: Embankment stabilisation on the Metropolitan Line
Stability assessment of a cutting through superficial deposits over Chalk on the Metropolitan Line found that most of the cutting fell below the minimum standards set by London Underground.
Cementation Skanska and Mott MacDonald developed a scheme to regrade the unstable deposits at the top of the slope and use the material to create a berm to form a toe weight at the base. Trees cleared at the top of the slope to enable the works were cut up as firewood and given to local residents, farmers and a school to reduce the need to transport the material away from site.
The approach is estimated to have saved £2M over a conventional approach and reduced carbon dioxide emissions resulting from transport of waste material by 28t.
Wardell Armstrong: Ballynacor Waste Water Treatment Works sewage sludge remediation
Assessment of former sewage sludge settling lagoons at Ballynacor identified a risk of ongoing contamination to local water sources and a stabilisation and solidification design was developed by Wardell Armstrong. The remediation design included the use of sewage sludge incinerator ash that would normally be sent to landfill, which removed the need to import pulverised fuel ash (PFA) from a power station 20km away to complete the work. According to Wardell Armstrong, there is no market for the reuse of sewage sludge incinerator ash, whereas PFA is a valuable commodity.
West Dorset District Council, CH2M, Balfour Beatty Construction Services UK and Aecom: Lyme Regis environmental improvements, Phase IV
Stabilisation of the landslide on the eastern side of Lyme Regis has been described by the Environment Agency as the largest and most complex coastal stabilisation schemes in the UK. The challenge to the designers and contractors was to undertake this major civil engineering scheme in an ecologically and geologically sensitive setting, which has Unesco World Heritage Site status.
Detailed mapping and surveying of the ecology was carried out ahead of the work to ensure appropriate mitigation measures were planned and implemented.