2430 x 2430 px | 41,1 x 41,1 cm | 16,2 x 16,2 inches | 150dpi
Date de la prise de vue:
13 décembre 2002
Lieu:
Stratford, London, UK.
Informations supplémentaires:
Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.
The huge Stratford Box on the Channel Tunnel Rail Link (Contract 230) is 1075m x 50m with a depth of 25m to accommodate Stratford International Station and 160km/h crossovers allowing parked trains to accelerate up to the CTRL main line speed of 230km/h. The box has reinforced concrete diaphragm walls 1.5m thick and the centre section of the box is constructed using cantilever diaphragm walls. The base slab is concrete and acts as a strut to the diaphragm walls. The ‘Box’ is effectively a huge concrete lined trench cut into the native geology. Though the station box has been designed to avoid inundation from the River Lea and other measures are in place to dispose of rainwater, it wasn’t built to resist the uplifting effects of rising groundwater that (in a worst case scenario) might cause the structure to float like a gigantic concrete barge. To avoid such problems, the lower aquifer water level is maintained 10m below the base slab and a permanent de-watering system has been installed using submersible pumps in 22 boreholes drilled 30m into the chalk. The £5.2 billion Channel Tunnel Rail Link (now High Speed One) was built between 1998-2007 and partly funded by the European Union, it forms a section of the Trans European Rail Network. It is basically a French-style high-speed rail line linking London with the Channel Tunnel, the Eurostar trains were developed on proven technology from the French TGV high-speed system. Stations on the CTRL are the existing Ashford International and new stations at Ebbsfleet and Stratford. The line ends at the rebuilt St. Pancras. Fourteen new tunnels were constructed, the longest being the London Tunnel which is 10.5km long from Ripple Lane to Stratford, after which the line briefly comes to the surface at Stratford Station. Five huge shafts of 17.15m diameter ventilate the twin bore, single-track tunnels and provide emergency access and evacuation points.
