Other important projects

High Speed Tunnels Guadarrama

Madrid-Segovia, Spain


The 28,7 km long, twin-bore Guadarrama tunnel is the longest railway tunnel in Spain and the fifth in the world. These tunnels are the first and only high speed tunnels of that length excavated without intermediate access shafts. The tunnels were bored through granite (26%) and gneiss (62%), with compress strenght usually greater than 80 MPs. Average quartz content was 30 – 35 %. The TBM bore rate at the Guadarrama tunnels, the greatest civil engineering project ever built in Spain, reached a milestone 80 m/day advance. The average daily bore rate was 16,6 m The excavation was performed with four 9,5 m diameter double-shield telescopic Tunnel Boring Machines (TBMs) constructed by Herrenknecht and Wirth. 2 TBMs were launched from the North portal  (one from each supplier) and 2 from the South portal (one from each again).

Concurrently  with the excavation, the machines installed the tunnels’ final lining, composed of 32 cm thick, 1,6 m long prefabricated ring segments, bolted in all directions. The useful tunnel diameter is 8,5 m; In keeping with standard safety regulations, the final tunnel project includes connection galleries, 250 m apart, but temporary connection galleries, 1000 m. apart, were constructed during construction to guarantee the safety of the workers.  A 2500 m2 Emergency and Evacuation Room with capacity for 1,200 people was constructed between the tunnels at the mid-point of the project. This room has a separate, independent ventilation system that guarantees fresh air during 48 hours in case of fire. This design/build project also included track installation, both on  ballast and on fixed plates (49,378 m). The work was completed in 57 months.

FACTS OF THE PROJECTS
Length: 2 x 28.700 m
Excavation diameter: 9,51 m.
Excavation volume: 4.075.000 m3
Inner diameter: 8,50 m