Abdalajis East Tunnel Breaks Through on Cordoba-Malaga High Speed Rail Link A ceremony presided by Magdalena Alvarez, Spain's minister of public works, was held on 13th February, 2006 to mark the end of tunnelling at the Abdalajis east tunnel, located in the municipalities of Antequera and Alora in the province of Malaga, Andalusia. The Abdalajis east tunnel (section 12) has been the most complex construction project on the 155 km Cordoba-Malaga high speed line. The line will include more than 24 km of tunnel, among which the one just completed and five others built in Alora, Cartama, El Espartal, Gibralmora and Tevilla. Progress rate of the line as of 31st January, 2006 was 81%. Click es/41.The Cordoba-Malaga high speed link has been divided in 22 sections. One of its outstanding achievements is the Abdalajis twin bored tunnel, consisting of single-track twin bores of 8.8 m of internal diameter (and cross section of 51.4 sq m) across Sierra del Valle de Abdalajis and Sierra de Huma. The east tunnel has a length of 7,270 metres (7,043 m of TBM-driven tunnel and 227 m in cut-and-cover). The east tunnel, which reached a milestone with the completion of tunnelling, was awarded to a JV between Dragados, Tecsa, SELI and Jaeger, for EUR117.6 million. Work commenced in November 2003. Tunnelling started from the south end using a double shield TBM for rock, christened 'La Alcazaba' and produced by MHI-Duro Felguera, with Robbins design (read E-News Weekly 32/2003 & 22/2003). The excavated diameter is 10 metres. Visit www.gdfsa.com and www.robbinstbm.comThe TBM which completed its job punched an aquifer in March 2005, causing the loss of a volume of 400 litres a second, which obliged to temporarily stop construction (read E-News Weekly 15/2005). A drainage system was designed to channel the groundwater to a decanting pond which function was to clean it up and improve its quality. After this filtering phase, the water was rejected into River Guadalhorce, which it supplied during a particularly severe drought in the region. In May 2004, construction was already held up after a methane gas pocket was encountered (read E-News Weekly 36/2004 & 23/2004). The support and lining of the tunnel consists of rings formed by seven 45 cm-thick x 1.5 m-wide prefabricated reinforced-concrete segments. The lining rings are made of a mixture of round-shaped reinforced concrete and steel fibres to improve the resistance in the corners and edges. To fit the shape of the segmental rings into the tunnel diameter, the segments feature an alternated conicity at the right and left hand sides and carry along the edge a rubber gasket to provide watertightness between the segments and rings. The segments are connected together by means of fasteners. The rings are connected together with connectors that help centre the segments and facilitate their correct placement. The waterproofing of the prefabricated lining rings will be reinforced constructing double internal reinforced-concrete rings in two zones of approx. 700 metres in each of the tunnels where further measures must be taken to obtain the perfect watertightness of the project and avoid the ingress of water.Construction of the west tunnel (section 13), of the same length, is well advanced and the second identical TBM is expected to hole through in March. Read E-News Weekly 5/2006. Visit www.adif.es and www.abdalajis.com 09/06.