WITH THE WESTERN bore holed through at 12.30 on June 1, tunnelling work has been completed on the 28·4 km Guadarrama tunnel on the Madrid - Valladolid high speed route. Spanish Development Minister Magdalena Álavarez had been on hand when the eastern bore was completed on May 5.
The boring of the world’s fifth-longest rail tunnel began on September 28 2002 and the total cost of the project is €1·22bn, 85% of which has been provided by the European Union’s Cohesion Fund. Situated 30m apart and connected by cross-passages every 250m, the bores with an internal diameter of 8·5m were dug using four double-shield TBMs. Concrete tunnel lining segments were cast at plants located at each end of the bores partly using excavated material, with 22% of the 4million m3 of spoil recycled during construction.
