Diseño antisísmico en los viaductos SG25, SG27 y SG28 de la línea de alta velocidad Atenas-Tesalónica

Antiseismic design of viaducts SG25, SG27 and SG28 in the high speed railway line Athens-Thessaloniki

The Lianokladi-Domokos Section of the New Double Track High Speed Railway Line between Athens and Thessaloniki includes some postensioned concrete box girder bridges. The structures SG25 y SG28 were incrementally launched from one abutment and the structure SG27 was built following a span-by-span construction on conventional falsework.Due to the high seismicity of the area (ac = 0,39 g), an isolation-damping strategy has been adopted by means of various anti-seismic devices on piers and abutments: elastomeric bearings, spherical bearings (guided or fixed), pendulum bearings and shock transmitters-dampers (transversal and longitudinal). Thus, seismic energy input is reduced whilst damping limits deck movements. A complete dynamic non-linear time-history was conducted, applying seven pairs of real accelerograms to the models of the bridges.