The MORE consortium will construct the £1.25 billion project for the Stonehenge Bypass on the A303 route in the UK. The consortium comprises Webuild with a 42.5% stake, FCC Construcción with a 42.5% share and BeMo Tunnelling UK with the remaining 15%.
The project is to improve the A303 trunk road and the key portion will be the excavation of a dual tube tunnel near Stonehenge between Amesbury and Berwick Down in southern England. The partners were named preferred bidders in May. The work entails building a 13km dual carriageway including a 3.3km tunnel that will remove traffic that passes through the UNESCO World Heritage Site and return the landscape to something resembling its original setting. The project is to create more than 1,000 jobs.
Known as the A303 Stonehenge – Main Works Contract, it covers the construction of the proposed tunnel’s civil, structural, mechanical, electrical and technology components, including the tunnel-boring machine, along with the approach roadworks and structures and the environmental components. Construction is to last five years.
The project is not without its share of controversy. Archaeological and environmental groups have opposed the work because of the historical importance of the area and the environmental issues involved. The project is required as the stretch of the A303 alongside Stonehenge only features a single lane in either direction and suffers frequent traffic delays. Carrying a high percentage of heavy trucks, there are serious safety concerns over the existing route and crashes are a risk.
Nor will the work be easy. Tunnelling through the ground in the area will be difficult as the geology is poor with fragmented and faulted rock, as well as a high water table. Ensuring the tunnel bores remain structurally sound will require vast quantities of concrete, while they will also have to be fully waterproofed. Extensive drainage including treatment facilities will have to be installed to prevent contamination from the roadway reaching local water courses.