Montabliz Viaduct | Spain
Cantabria is a mountainous region along the north central coast of Spain. The mountains hold deep valleys, fast-moving rivers, many caves and some of the world’s most significant archeological sites.
Spain needed a modern, fast and safe highway across its mountainous northern terrain. The answer was the new A-67 Meseta Higway from Madrid to Santander, the Cantabrian capital. The curving highway required the highest bridge ever built on mainland Spain – the Montabliz Viaduct.
Louis Berger designed Montabliz Viaduct at the behest of the Ministry of Public Works, General Roadway Directorate, Spain. The viaduct towers 490 feet above the Bisuena River as the most expensive component of the costliest stretch of highway in Spain’s history.
The dramatic structure was built by the balanced cantilever method, with a central span of 574 feet flanked by two smaller spans of 509 feet and approach spans of 413 feet and 361 feet. The five spans follow a continuously curving arc with a radius of 2,297 feet. The 85 foot wide, 5-lane deck is banked at 8 percent to counter the forces of the curving roadway. Each of the four massive piers was built with self-climbing formwork, a first for a bridge in Spain.
A tapered shape was maintained on all four sides to keep the mass of towers to a minimum while retaining an elegant profile blending into the valley of trees. Using the largest traveling cranes ever manufactured in Spain, the spans were built outward from the tops of the towers in 16-foot sections.
In 2010, the Montabliz Viaduct was awarded the Segovia Aqueduct Award in Spain and was nominated for a 2010 fib Award for Outstanding Concrete Structures award by the International Federation for Structural Concrete (fib - fédération internationale du béton) Third International Congress in Washington, DC.