ACCIONA Construction Receives Award for Pajares Tunnels Lining

By TBM News March 20, 2017

Members of the ACCIONA team were on hand to receive the JEC Innovation Awards.

ACCIONA Construcción has been recognized at the JEC Innovation Awards 2017 for the composite lining that it designed and patented to waterproof the 24-km Pajares twin tunnels, which form part of the route of the future high-speed railway between Madrid and Asturias and are among the longest tunnels in Europe.

The JEC Innovation Awards are presented every year to the best initiatives in the world of composite materials, recognizing projects that stand out due to their technical interest, potential markets, environmental impact or originality.

The awards are divided into 13 categories, including sectors such aeronautics, the automotive industry, 3-D printing, sports and construction. According to the jury, ACCIONA Construcción received the award in the latter category for its “innovative composite panels, as an alternative to steel and concrete in the construction of high-speed railway tunnels.”

Various solutions were studied to solve the problem of water seepage in these two tunnels before ultimately opting for the use of composite sheets that channel the water. The panels, which are 9.2 m long and 1.5 m wide, comply with the clearance criteria for the tunnels and enable the ring segments to be inspected. The flexibility of composite materials means that the panels can be adapted to the shape of the tunnel and its irregular features.

Fiberglass reinforced polymeric resin was chosen as the material for these panels. These sheets are manufactured using a pultrusion process in which the fiberglass is impregnated with a resin that sets hard when heat is applied. Once they have been manufactured, the sheets are transported via conventional means to the site, where each pair of panels is used to line 1.5 m of tunnel.

The composites used in the final lining also offer other advantages such as easy maintenance and a high resistance to corrosion compared to traditional construction materials used in these types of projects.

In addition to the functional advantages, the award-winning solution offers a significant reduction in CO2 emissions and once again demonstrates ACCIONA’s unwavering commitment to innovation and the environment.

More than 15,000 panels were produced to line more than 200,000 sq m of tunnel, using a total of 1,700 tons of composite materials.