Viaduct over the C-66 road

Name and location
Viaduct over the C-66 road in the town of Sant Julià de Ramis (Girona, Spain)
High Speed Line Madrid-Zaragoza-Barcelona-French border. Section Sant Julià de Ramis – Cornella del Terri.

Key features
Length: 287m. Spans: 31m + 2 x 44m + 55m +65m + 48 m.
Average height: 12m
Use: High Speed Railway
Materials: Reinforced concrete piers and prestressed concrete deck.
Construction: Span by Span with falsework supported on land, with a portal frame falsework under C-66 road.

Railway Infrastructure Administrator ADIF.

Years: 2007-2010

BT Intervention
Construction project for COPROSA, Technical assistance and engineering construction works.

General information
Construction pictures

General information

The viaduct, with a total length of 287m, is a continuous prestressed concrete box beam with spans 31 + 2 x 44 + 55 + 65 +48 m, with an average height of 10.0m above the ground. The spans distributions respond to the adaptation of the viaduct to several crossings: over the C-66 motorway, over the C-150A road, and over various county roads and underground services in the area, among which there is a storm drain that, if extreme rainfall, it is able to channel all the water flow, causing flooding in a small valley between P3 and P4 piers

The skew crossing over the C-66 motorway requires a span of 65m length, which makes conditional the geometry and the construction procedure of the deck. In this section, the highway has two lanes southbound and two lanes plus an addition lane, northbound.

The longitudinal static scheme is the classical in railway bridges:

– A continuous prestressed concrete box beam supported on piers and abutments.
– Fixed point against longitudinal actions located on an abutment. Transverse fixing off the deck to all piers of solid double-T section

So, the deck is a prestressed concrete continuous beam of 6 spans, simply supported on piers and abutments, suitable for a 14.0m-wide platform. The cross section is a box beam 3.14m height(3.0 at the edge), which increases to 5.14m at the supports on the piles P4 and P5, belonging to the span of 65m. The bottom slab has constant width equal to 5.0m, except in areas of variable depth, which respects the inclination of webs and the bottom slab should be narrower. The reduction in width is offset by a thickening of the bottom slab that, without generating additional internal forces (being very close to the support section) and additional consumption of concrete almost negligible, allows toincrease the ductility of the support section, with the Ultimate Limit State advantages that this fact implies

The cross sections of variable depth cannot be longer than 10.0m counted from the center stack support, because the formwork for their execution would invade the gauge of the road

It is noteworthy that the viaduct is located in an area of moderate seismic activity, with basic soil acceleration a = 0.09g, this action hasbeing decisive in the design of many elements of the structure.

The foundations of the piers are piles of 1500mm of diameter. The foundations of the abutments can be direct by conventional footings

The deck is constructed by the span by span method on a falsework supported on the ground, concreting the cross sections into two sub-phases. The first span concreted was number 5 and from there the construction progressed towards two ends.


Viaduct over the C-66 road 1

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Viaduct over the C-66 road 2

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Viaduct over the C-66 road 3

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Viaduct over the C-66 road 4

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Viaduct over the C-66 road 5

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Viaduct over the C-66 road 6

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Construction pictures