High-Speed Railway Line Vitoria – Bilbao – San Sebastián. Section: Elorrio.
This 3 km segment of the Spanish high-speed railway line runs through the municipality of Elorrio in the Bizkaia province, extending from west to east, approximately 1 km away from the urban center.
This segment is a crucial link connecting the three provincial capitals of the Basque Country. The design includes five railway axes and two single-track platforms that merge into one double-track platform in the middle, before returning to two single-track platforms in the final 200 meters.
The design had to address the region's challenging orography. Severe slopes necessitated the construction of five viaducts, some of which are up to 500 meters long and 75 meters high, such as the Zumelegui viaduct. A notable feature is the Zabaleta Sur viaduct, which, while not remarkable for its length or height, was uniquely designed to pass over a pier of an existing high-speed viaduct from the Atxondo - Elorrio segment of the same line. Despite the challenging elevation, a 206-meter-long cut-and-cover tunnel was required at the highest point of the segment.
Given the difficult terrain, constructing these structures in such an unfavorable environment demanded the design of several access roads. While initially intended to be temporary, some of these roads are expected to improve accessibility to the area in the future.