Brisa – Auto-estradas de Portugal
The widening of the PH20 Viaduct is the direct consequence of the improvement works planned for the Carregado/Aveiras Stretch of A1 in order to ensure the continuity of the motorway platform with its cross-section of 2×3 lanes.
A similar structural solution to the existing bridge was designed for the widening of this viaduct.
The existing viaduct, with a total length of 231,5m, consisted of two separated decks. The deck structure consisted of 8 independent spans comprising a plane grid with 12 longitudinal precast prestressed beams and 6 prestressed cross beams. Regarding the widening, the application of 4 longitudinal beams per deck was required. These beams were bonded to the existing beams through a compression slab, 0,1m thick, and through the adaptation of the cross beams.