PAYMACOTAS - Consulting and assistance services for the supervision of the construction works of Highway A-63 (Oviedo-La Espina) and Road N-634 (San Sebastián-Santiago de Compostela) Section: Grado (O)-Doriga, from km 2+500 to 6+500
The main trunk of the highway has a length of 4,218 m and runs from east to west, making two turns. First, it turns to the left up to El Fresco Tunnel, a two-tube tunnel with one tube per carriageway. The left one has a length of 949 m (904 m of excavated tunnel + 45 m of cut-and-cover tunnel) and the right one has a length of 923 m (878 m of excavated tunnel and 45 m of cut-and-cover-tunnel). The horizontal alignment has a constant radius and a constant gradient of 0.6%.
Doriga Junction is located at the end of this road section: a trumpet junction intended to access SL-9 road by means of a roundabout at the end of the bidirectional branch line of the junction. The route also includes an access to AS-15 road, with a length of 720 m.
The works comprised 9 structures (3 overpasses and 6 underpasses). The overpasses were built with post-tensioned slabs and a prestressed lightweight concrete deck with 6 double T-beams, 2 m thick. The underpasses are frame-type structures with 7 x 5 m clearance, with the exception of two: one of them is composed of an arch span and a deck built with double T-beams; the other is made of a reinforced concrete vault with a 7 m horizontal clearance.
The project included the construction of 17 culverts of different sizes and installation of control and safety systems in the tunnel.