Alenquer, Pombal, Portugal
This preliminary assessment regarded the Bridges and Viaducts of the C1 Stretch – Alenquer (Ota)/Pombal of the high speed railway connection between Lisbon and Oporto. At this stage, in which all the alternative railway corridors were considered, a total length of approximately 43km, include 64 bridges and viaducts with an average height of 30m above the ground, were studied. One shall also emphasise that low vertical or horizontal deformations in structures is a main requirement of the high speed railway network. As a consequence, one shall avoid the use of large spans even at significant heights, which, with regard to the crossing restrictions, led to a maximum span of 92m. The defined structural solutions aimed the fulfilment of basic maintenance demands as well as the reduction in the number of bearings and rail expansion joints. Hence, the designed structures are continuous and also compatible with the ballasted railway track solutions with continuous welded rails (CWR). This assessment also included 73 overpasses and 58 underpasses.