Los Gallardos – Sorbas High Speed Railway Viaducts. New Anti-Seismic Device to Face Horizontal Forces

In Los Gallardos – Sorbas segment of the High Speed Railway between Murcia and Almería, there are 4 viaducts built span by span: Almocaizar Viaduct, Barranco Hondo Viaduct, La Gloria Viaduct and Barranco Los Giles Viaduct. This bridges are formed by a continuous concrete single-cell post- tensioned box-girder, erected span by span by means of a self launching formwork gantry and full shoring. They are situated in a medium risk seismic zone. In order to face the longitudinal earthquake action, a new anti-seismic device has been designed. It consists of hydraulic viscous dampers, to dissipate energy, in the abutments and sliding pendulum bearings with low friction, for recentering, on the piers. A nonlinear seismic analysis was carried out for the dimensioning of the anti seismic devices. Artificial acceleration time history for the earthquake analysis was needed.