The structure consists of an isostatic pergola with a single span of 10.50 m (design span) over the existing railway, which is crossed obliquely by high-speed train lines at an angle of approximately 7 centesimal degrees. The deck typology is a beam-slab system with prestressed beams measuring 0.70 m in depth, spaced at 0.67 m intervals, and a compression slab with a minimum thickness of 0.07 m, resulting in a total structural depth of 0.77 m.**

The compression slab has a variable thickness, with a minimum depth of 7 cm at the ends and a 2% camber on both sides of the high-speed line axis, reaching a maximum depth of 19 cm at the center.

The deck is subdivided into two zones: Zone 1, the central area under the railway tracks, which is 105 m long; and Zone 2, the exterior areas of the deck. The number of prestressing tendons in the beams varies between these two zones, with 8 strands of 0.6” diameter in Zone 1 and 6 strands of 0.6” diameter in Zone 2.

Due to the structure’s typology, elastomeric bearings with confinement reinforcement are placed under the beams. Two bearing sizes have been defined according to the maximum loads they must support: 150x200 mm bearings on the abutment walls, and 100x150 mm bearings in the pier zone. The total height of the bearings is 28 mm, with a net height of 20 mm in both cases.

The abutments are composed of a reinforced concrete wall section and a portal frame section formed by concrete columns and a lintel that supports the beams. The abutment foundation consists of deep foundations using piles with a diameter of 1.00 m and a length of 14.00 m, embedded at least 6 diameters into the competent stratum.

The abutment wall has a constant thickness of 1.10 m. It is supported on a pile cap measuring 6 m in width and 1.30 m in depth, with a transverse pile spacing of 4.00 m and a longitudinal spacing of 2.50 m.

The portal frame section is composed of 12 columns, each 5.98 m high with a cross-sectional area of 1.10 x 0.60 m. These are supported on a pile cap measuring 2.20 m in width and 4.50 m in length, resting on two piles spaced 2.50 m apart longitudinally.

Given the considerable length of the portal frame section, if all the columns were fully fixed to the lintel, they would be subjected to extremely large forces due to imposed deformations. Therefore, for the six columns furthest from the pergola’s center, guided POT-type bearings are used. These allow for longitudinal deformation along the abutment while restraining transverse movement.

At both ends of the structure, cantilever retaining walls are built, founded on spread footings. These walls have a variable thickness and a back face slope of 15V:1H, with a thickness of 0.30 m at the top. Five types of walls are defined according to height, separated by expansion joints.