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GUADARRAMA TUNNELS, SOUTH END NEW RAIL ACCESS TO THE NORTH AND NORTHWEST OF SPAIN. SOTO DEL REAL – SEGOVIA STRETCH TECHNICAL ASSISTANCE FOR THE CONTROL AND SUPERVISION OF WORKS Segovia, 2002-2007 • Birdseye views of the south end of the tunnel and the tunnel boring machine. • In accordance with the Environmental Impact Declaration, the entrances are located before the crossroads with the M- 611 road from Soto del Real to Miraflores and the excavation waste was transported on belts to the transfer plant for loading on rail wagons. Phase 2 of the project for the South End of the 16.7 km long Guadarrama Tunnel begins in the municipal district of Miraflores de la Sierra and soon reaches the 2,131 m long Soto Siding, with a gradient of 3‰. The layout crosses the M-608 road from Soto del Real to Guadalix de la Sierra, and continues over the Matarrubias stream by means of a 660 m long viaduct. At a distance of 3.4 km from the start of the stretch, the separation of the two tracks leads to the south end of the two single-track tunnels with a gradient of 3‰. The tunnel crosses the Morcuera Range with a maximum cover of 960 m (5.3 km from the mouth). At the highest point of the layout it starts the descent to the end of the stretch. The excavation of the mined tunnel, with a length of 13.4 km and an inner diameter of 8.50 m, was performed with two double shields of 9.46 m Ø clad with 32 cm thick prefabricated voussoirs, forming standard rings with a base voussoir and an inner radius of 8.50 m. The standard rings were composed of 6 voussoirs plus the keystone. To ensure safety, 11 connection galleries were built between the tunnels, 250 m apart, and an emergency room was designed (equivalent to a 500 m long by 5 m wide gallery), totalling just over 800 m of linear excavation. Furthermore, ~300 m of passing loops were also created.
