On September 2016, a lateral displacement was detected in the viaduct located in the road Z-32, above the highway AP-68 and railway tracks. The 18m displacement was found on abutment 1 of the right carriageway, in the province of Zaragoza. In view of this Freyssinet and INES Ingenieros were commissioned the Spanish Ministry of Development to inspect the viaduct’s bearings and deliver a technical report and suggest an emergency solution.

On the basis of the inspection and structural assessment, it was concluded that the causes of the registered displacement were unanchored elastomeric bearings with non-standardized dimensions. Bearings have great stiffness under bending stress in relation to their larger dimension. When they are used in high skewed bridges, the larger dimension depends on the piers’ axes and meets the beams’ axis at a great angle. An unusual bending stress is created on the bearing. EN-1337-3 checks indicate that some bearings are unstable with respect to rotation.

In order to solve the problem, INES Ingenieros suggested the replacement of the existing bearing devices by anchored/ embossed bearings, reconstruction of some of the joints and repositioning of the deck. To this end, it was required to lift, stabilize and lateral translation of the deck.