en.Wedoany.com Reported - The first "green tunnel" built using the "cut-and-cover" method on the UK's HS2 high-speed railway project has recently been completed. Named the Copthall Tunnel, the structure is 880 meters long and located near West Ruislip in the western suburbs of London.
The tunnel construction utilized 1.2 million cubic meters of material excavated from the nearby Northolt twin-tube tunnel project. Engineers employed the "cut-and-cover" method during construction, allowing all excavated material to be reused on-site for backfilling, thereby eliminating approximately 100,000 truckloads of earth transportation and significantly reducing the impact on the local community and environment. The Copthall Tunnel is the only single-bore tunnel on the HS2 route, designed to withstand forces generated by trains traveling at speeds of up to 200 miles per hour (approximately 320 kilometers per hour). The project was constructed by the SCS joint venture (comprising Skanska, Costain, and Strabag), which is responsible for civil engineering works on the southern section of the line. UK Minister for Rail, Lord Peter Hendy, stated that the completion of the Copthall Tunnel is a significant milestone for HS2, with innovative engineering solutions integrating the tunnel into the landscape and avoiding extensive transportation by utilizing materials on-site.
The Copthall Tunnel is the first of five planned green tunnels along the HS2 route from London to the West Midlands to complete structural construction and backfilling. In the next phase, the tunnel surface will be greened with trees and vegetation planted to naturally blend it into the surrounding environment. The remaining four green tunnels are also in the late stages of construction, with the Chipping Warden Tunnel in Northamptonshire having completed structural work before backfilling. The Copthall Tunnel is located between the Northolt Tunnel and the Colne Valley Viaduct, the latter being the UK's longest railway bridge, which was completed last year. The tunnel structure is over 800 meters long, approximately 12 meters high, and 16 meters wide internally, equipped with five natural ventilation shafts.
HS2 Ltd is implementing a comprehensive project restructuring plan to optimize costs and improve efficiency. According to the UK Department for Transport, by simplifying certain design and operational aspects, savings of up to £2.5 billion can be achieved, with the construction timeline shortened by approximately one year.
