Section 8b: Larraskitu – Buia of the Bilbao Metropolitan South Link road
Type of worksHighway
The section in the main has two parts:
The first consists in widening to 4 lanes the A-8 both in the direction of Cantabria as well as in the direction of Guipúzcoa. The works took place on both sides of the road, with some 1600 m, from the trunk with the A-68 up to the Zabálburu exit. The singular feature of these works is that they took place while maintaining the service of the three existing carriageways, which had to be completed in eight phases. The works consisted in various types of walls (breakwaters, prefabricated walls, in situ) and a widening of the explanatory and asphalt.
The second part was the completion of the Larraskitu link. To do this a hypostatic mixed structure of 150 m was required, with five vanes, and a maximum pile length of 22 m; an inferior passage below the A-8 using reinforced concrete piles and slabs, subsequently excavating the mine; and finally moving the Miribilla exit by 50,000 m but with micropile walls that are anchored with 90 ton anchorings.