Arcos de Alconétar Viaduct (analysis)

A detailed assessment of the condition of an object.


Element type
"During construction, the action of the wind triggered a resonant response in the structure in January 2006 (vortex shedding). The structure was just the freestanding arch (the columns had not yet been assembled).

The phenomenon produced considerable damage at intermediate sections of the arch. The movement was an antimetric vibration of the arch in its plane with a frequency of 0, 70Hz (second mode).

A dynamic data acquisition system was installed and more than 2.600 wind events were recorded between February and June 2006. Aerodynamic deflectors were installed (see picture below).

They proved to be very effective in suppressing or reducing the formation of vortexes.

However, It was decided to keep the dynamic monitoring system with the bridge opens to traffic to survey the structural behavior under the wind action. The opportunity was taken to obtain information regarding joint movements and other environmental actions.

The total amount of sensors is 54 (thermometers, anemometers-vanes, accelerometers, and lasers for joint displacements)."
Case type
Initiation of assessment
Pure research interest
Predominant verification type
Engineering judgement
Predominant verification scale
Structural component
Structural analysis
Ultimate limit state, Fatigue limit state, Serviceability limit state
Information updating
Indirect non-bayesian
Physical intervention
Operational intervention
Maintenance, Monitoring

Other initiation of assessment: Verification of the correct structural behavior due to the vibration problem detected during construction.

Other physical intervention: Physical intervention (strengthening/Upgrading) will only be considered if the structural behavior during working life is found to be not suitable.