Static and dynamic testing of highway bridges: a best practice example

The load bearing capacity of a viaduct and its structural behaviour under traffic or seismic excitation can be evaluated using well-established modelling methods aided by computing facilities of great capability. However, to ensure reliable results, numerical models used in designing should be calibrated with accurate information on material properties and structural components. The static and dynamic testing procedures applied to a multi-span bridge along a new highway link inaugurated in 2014 in northern Italy are examined as a best practice example. The structural responses and performances are compared with and evaluated in the light of static and dynamic load test results. In particular, Operational Modal Analysis and Experimental Modal Analysis are used and compared to match with the numerical model. The comparison showed that the dynamic load test can supplement the static load test for the structural evaluation of new viaducts; it may also be taken as an alternative for the monitoring of operational viaducts.