It is nighttime, and the section of the A24 between Tornimparte and L’aquila Ovest is closed to allow a very delicate and spectacular job to take place.
We are in the final stages of earthquake-proofing the Genzano Viaduct, a few kilometers from L’Aquila. Here the old piers have been demolished and replaced with new ones made of corten steel. So is the new deck, which will be built of this material, which is much stronger, elastic, and earthquake-resistant.
The first stages of the launching took place during the daytime, without having to close traffic on the highway and ordinary roads below. For this last span, 25 meters long, 10 meters wide, weighing more than 40 tons, traffic had to be stopped. Therefore, the operation is to be completed in a few hours, so as not to cause further disruption to traffic.
The span will have to be moved more than 30 meters from the existing viaduct, adjacent to its final location. To do this, two cranes are being used, one 400-ton crane and one 250-ton crane, one of which works from below and is at an elevation about 25 meters below the viaduct floor.
This span concludes the main structure of the viaduct, which has been completely replaced, because the previous one was demolished and new piers, made of corten steel, filled with concrete, have been rebuilt. And the first three spans consisting of corten steel beams have already been laid as well.
Being within the crater of the L’Aquila area, seismic actions are strong and it is necessary to build structures that have particularly advanced performance characteristics.
The new steel structure is lighter than the previous structure, which was made of reinforced concrete, and prestressed concrete, and is characterized by better resistance to seismic actions.
Cover photo: copyright Enzo Liberati for I.B.A. CRANE S.r.l.
