Two 10.2m diameter Robbins/Mitsubishi TBMs arrived on the site of the 7km long Abdalajis rail tunnel in Spain last month, ready to start boring in September.
The machines were constructed by Spanish manufacturer Duro Felguera. Robbins supplied the basic TBM design, including cutterheads, while Mitsubishi heavy Industries designed the other components.
One machine is going to the Ute Abdalajis consortium (Dragados, Tecsa, SELI and Jaeger), which will bore the US$114M east tube, and the other is going to the Sacyr/Somague JV, which will use it to bore the US$120M west tube.
The machines have a cutterhead power of 4,900kW, and a maximum cutterhead thrust of 82,500kN. They will erect a 450mm thick pre-cast concrete lining behind them, bringing the internal diameter down to 8.8m. Nineteen cross-passages, 25m-30m in length, will also be constructed.
The alignment passes through hard rock, which comprises: quartzite (11.2%); sandstone and pizarra (6.2%); flysch, conglomerate and lutite (12.8%); limestone, marl and marly limestone (61.2%); dolomite, limestone and marl (8.6%).
Engineers hope to build the tunnel in 36 months, one year less than officially stipulated.
The contract was awarded by Gestor de Infraestructuras Ferroviarias (GIF) as part of the 155km long high-speed rail link between Cordoba and Malaga.
